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CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of U.S. application Ser. No. 11/505,788, filed on Aug. 18, 2006, entitled “Creation and Transmission of Part of Protocol Information Corresponding to Network Packets or Datalink Frames Separately” which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION [0002] The present invention relates to efficient transfer of datalink frame or network packets in a “custom” network. The network is “custom” as all switches and end nodes need to create or process datalink frames or data packets of special formats. [0003] The OSI, or Open System Interconnection, model defines a networking framework for implementing protocols in seven layers. Most networking protocols do not implement all seven layers, but only a subset of layers. For example, TCP and IP protocol corresponds to layers 4 (TCP) and 3 (IP) respectively. Network packets contain protocol layer information corresponding to the packet. For example, a TCP/IP packet contains a header with both TCP and IP information corresponding to the packet. [0004] The physical layer (layer 1 ) specifies how bits stream is created on a network medium and physical and electrical characteristics of the medium. The datalink layer (layer 2 ) specifies framing, addressing and frame level error detection. For outgoing packets to the network, the datalink layer receives network packets from networking layer (layer 3 ) and creates datalink frames by adding datalink (layer 2 ) protocol information and passes the frame to the physical layer. For incoming packets from network, datalink layer receives datalink frames from physical layer (layer 1 ), removes the datalink (layer 2 ) protocol information and passes network packet to the networking layer. The network layer (layer 3 ) specifies network address and protocols for end to end delivery of packets. [0005] Network packets contain protocol layer information corresponding to the packet. FIG. 1A illustrates a network packet containing 01001 layer 1 , 01002 layer 2 , 01003 layer 3 , 01004 layer 4 headers, 01005 Data and 01008 layer 1 , 01007 layer 2 , 01006 layer 3 trailers. FIG. 1B illustrates a network packet with 01011 layer 1 , 01012 layer 2 (data link), 01013 layer 3 (networking) and 01014 layer 4 (transport) headers and 01017 layer 1 and 01016 layer 2 trailers and 01015 Data. For each layer, the corresponding header and trailer (if present) together contain all the protocol information required to send the packet/frame to the the consumer of the data in a remote node. [0006] For example, headers/trailers corresponding to a TCP/IP packet in a 10 BaseT Ethernet LAN are: [0007] i) Physical layer header contains Start-of-Stream Delimiter [0008] ii) Data link layer header contains Preamble, Start-of-Frame Delimiter, Ethernet Addresses, Length/Type Field etc. [0009] iii) IP header contains Version, Length, IP Address etc. [0010] iv) TCP header contains Port Numbers, Window, Flags etc. [0011] v) Datalink layer trailer contains 32 bit FCS [0012] vi) Physical layer trailer contains End-of-Stream Delimiter. [0013] When parts of networks get congested and end nodes continue transmitting packets to congested parts of a networks, more and more switches can get congested. This can lead to switches dropping large number of packets, nodes retransmitting the dropped or lost packets and network slowing down. [0014] U.S. Pat. No. 6,917,620 specifies a method and apparatus for a switch that separates the data portion and the header portion. This method has a disadvantage that overhead and logic for separating the data portion and the header portion and then combining the header portion and the data portion before transmission is required. This method also can not consolidate headers from more than one packet for transmission to the next node or delay packet arrival if the destination path of the packet is congested and therefore, can not avoid congestion. [0015] According to claim ( 1 )(c) of U.S. Pat. No. 5,140,582, the header portion of a packet is decoded prior to the receipt of full packet to determine the destination node. This invention can help with faster processing of the packet within a switch. This method can not consolidate headers from more than one packet for transmission to the next node or delay packet arrival if the destination path of the packet is congested and therefore, can not avoid congestion. [0016] U.S. Pat. No. 6,032,190 specifies an apparatus and method of separating the header portion of an incoming packet and keeping the header portion in a set of registers and combining the header portion with the data portion before transmitting the packet. This method has a disadvantage that overhead and logic for separating the data portion and the header portion is required. This method can not consolidate headers from more than one packet for transmission to the next-node or delay packet arrival if the destination path of the packet is congested and therefore, can not avoid congestion. [0017] U.S. Pat. No. 6,408,001 improves transport efficiency by identifying plurality of packets having common destination node, transmitting at least one control message, assigning label to these packets and removing part or all of header. This method has a disadvantage that switches need to identify messages with common destination node and additional logic to remove header and add label. This method can not delay packet arrival if the destination path of the packet is congested and therefore, can not avoid congestion. BRIEF SUMMARY OF THE INVENTION [0018] It is the object of the present invention to create and transmit part of protocol information separately from the Datalink Frame or Network Packet (DFoNP) containing data. The Separately Transmitted Protocol Information is referred to as STPI. Network congestion can be reduced or avoided using STPI. [0019] According to the invention, there should be at least one DFoNP which contains the data and rest of the protocol information not contained in STPI, corresponding to each STPI. Preferably, there will be only one DFoNP corresponding to each STPI. The STPI and DFoNP together contain all the protocol information required to send the packet/frame to the the consumer of the data in a remote node. [0020] The creation of STPI and DFoNP is done by the originator of the frame or packet such as an operating system in an end node. The format (contents and location of each information in a frame or packet) of the frame or packet containing STPI and DFoNP should be recognized by the final destination of the frame or packet. The format of STPI and DFoNP should also be recognized by switches in the network. So preferably, all STPIs and DFoNP in a given network should be of fixed formats. [0021] Preferably, one or more STPIs are transmitted in a datalink frame or a network packet. The datalink frame containing STPIs is referred to as STPI Frame. The network packet containing STPIs is referred to as STPI packet. The switches in this case should be capable of extracting each STPI in an incoming STPI Frame or STPI packet and forwarding it to the next node in a different STPI Frame or STPI Packet. The switches can add each STPI from an incoming STPI Frame or STPI Packet into an STPI Frame or STPI Packet it creates. Preferably, the layer 2 address in the datalink frame containing multiple STPIs will be the next hop node address. [0022] Optionally, STPI Frame or STPI Packet contains number of STPIs or length of the STPI frame. Optionally, STPI Frame or STPI Packet contains the offset or position of STPIs in the STPI frame—this is required only if STPIs supported by the network are not of fixed length. [0023] Optionally, STPI Frame or STPI Packet does not contain the number of STPIs and switches in the network are capable of identifying the number of STPIs from length of the frame as they are of fixed length. [0024] Preferably, some protocol information contained in STPI may not be contained in the corresponding DFoNP. But protocol information contained in STPI and the corresponding DFoNP need not be mutually exclusive. In this method, the switches obtain both STPI and the corresponding DFoNP before the STPI and the corresponding DFoNP are forwarded. Optionally, STPI need not be forwarded to end node if sufficient protocol information is contained in the corresponding DFoNP. [0025] The proposed invention can be employed for data, control and/or RDMA packets in a network. [0026] The proposed method allows switches to read the more than one STPI, and then delay obtaining the corresponding DFoNP. The DFoNP may be read or forwarded in a different order compared to the order in which STPI are read or forwarded. This method allows switches to optimize resources and packet/frame forwarding efficiency. [0027] STPI contain temporary information such as current node or port number of the node containing the corresponding DFoNP. STPI also contains an address of a buffer containing the corresponding DFoNP or an offset in a buffer where the corresponding DFoNP is stored or an index of the corresponding DFoNP in an array. These information help in associating STPI to the corresponding DFoNP. The exact information contained in STPI whether it is an address or an offset or an index or a combination of these is implementation specific. [0028] Optionally, STPI may contain originating node identifier and a sequence number. Such information can help in reporting errors when STPI or corresponding DFoNP are corrupted or lost. [0029] Optionally, STPI may contain other vendor specific or DFoNP related miscellaneous information. [0030] Optionally, DFoNP may contain some information that help in associating itself with corresponding STPI, such as originating node identifier and a sequence number. Preferably, DFoNP sequence number is same as the sequence number of the corresponding STPI. [0031] Optionally, DFoNP may contain other vendor specific miscellaneous information. [0032] The originating node creating an STPI by creating and initializing one or more data structures. Preferably, there is only one data structure containing STPI. [0033] A switch receiving both frame containing STPI and the DFoNP before forwarding a frame containing STPI or DFoNP to the next switch or node. [0034] Preferably, a switch receiving frame containing STPI before reading the corresponding DFoNP. [0035] A switch can delay transmitting or reading DFoNP after the corresponding STPI is transmitted or received, allowing the switch to optimize its resource usage and improve efficiency. [0036] A switch can read DFoNPs corresponding to a switch port with minimum outbound traffic, ahead of other DFoNPs, thereby improving link efficiency. [0037] The switch modifying temporary information in STPI such as node number or port number corresponding to the node containing corresponding DFoNP and buffer pointer or index or offset for the corresponding DFoNP, when the DFoNP is transmitted to another node. [0038] If the DFoNP and STPI is forwarded to another subnet, layer 2 information in STPI and DFoNP should be updated to be compatible with the subnet to which it is forwarded (for example, in an IP network when a packet moves from Ethernet to ATM, layer 2 protocol information will have to be modified to be made compatible with ATM network). [0039] If STPI contains a multicast or broadcast destination address, the switch transmitting both the DFoNPs and the STPI to all next hop nodes identified by the address. [0040] A switch can delay reading or forwarding the DFoNP after the corresponding STPI is received or forwarded, and vice versa. [0041] A switch may or may not receive or transmit DFoNPs in the same order as the corresponding STPIs are received or transmitted from a switch port. [0042] Optionally, a switch may receive or transmit one or more DFoNP in one frame. [0043] For networks that support layer 5 / 6 / 7 (example OSI networks), STPI optionally containing part of or all of layer 5 / 6 / 7 information. Preferably, no layer 5 / 6 / 7 information may be contained in STPI. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0044] FIG. 1 illustrates datalink frames in normal networks. [0045] FIG. 2 illustrates examples of different design options for frames containing STPIs and the corresponding DFoNPs. [0046] FIG. 3 illustrates an option for transmitting STPI and the corresponding DFoNP to next hop node. [0047] FIG. 4 illustrates an option for transmitting STPI and the corresponding DFoNP to next hop node. [0048] FIG. 5 illustrates an option for transmitting STPI and the corresponding DFoNP to next hop node. [0049] FIG. 6 illustrates an option for transmitting STPI and the corresponding DFoNP to next hop node. [0050] FIG. 7 illustrates an option for transmitting DFoNP and optionally, the corresponding STPI to destination node. [0051] FIG. 8 illustrates examples of different design options for frames containing Read-STPI request. [0052] FIG. 9 illustrates examples of different design options for frames containing Read-DFoNP requests. [0053] FIG. 10 illustrates examples of different design options for frames containing Number-of-STPIs message. [0054] FIG. 11 illustrates Ethernet frames adhering to this invention. [0055] FIG. 12 illustrates PCI-Express transactions adhering to this invention [0056] FIG. 13 illustrates examples of design options for frames containing more than one type of requests or messages. [0057] FIG. 14 illustrates how this invention can be used by switches to reorder transmission of DFoNPs. DETAILED DESCRIPTION OF THE INVENTION [0058] There are a very large number of design options with network component designers with respect to the format of DFoNP, STPI and STPI frame/packet. FIG. 2 illustrates some examples of different formats in which the STPI and the corresponding DFoNP can be created adhering to this invention. The layer 2 , layer 3 , and layer 4 information that may be present in the DFoNP and STPI may or may not be mutually exclusive and is dependent on specific format or formats of STPI and DFoNP supported by switches and endnodes. Each network will employ only few STPI/DFoNP formats (preferably, as few as 1-3), one each for a subtype of a packet or a frame. Preferably, a network may employ only one format for STPI and one format for DFoNP to reduce complexity in switches and endnodes. STPI should have enough information for the switch to find the port for the next hop. [0059] i) FIG. 2A illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. All layer 2 02021 02024 (including Destination Node Address used for routing), layer 3 02022 and layer 4 02023 information are in STPI and the DFoNP contains no layer 3 and 4 information. DFoNP contains minimal layer 2 02001 02004 information mandated by datalink layer (an example of optional layer 2 information is the VLAN tag in Ethernet). Frame Type in the frame gives the type of frame, DFoNP 02002 , STPI 02012 , etc. All data 02003 are in DFoNP. Three STPIs 02013 are sent in a STPI Frame. The destination address 02011 of the STPI Frame is the next hop switch or node address. In this example, 3rd STPI 02014 in the STPI Frame corresponds to the DFoNP shown. The STPI contains the length 02026 of the corresponding DFoNP and the current node number 02025 and current buffer address 02026 containing the corresponding DFoNP. When the DFoNP is transmitted to the next node the node number 02025 and buffer address 02026 in the corresponding STPI are updated. [0060] ii) FIG. 2B illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. The frames in this network do not have layer 2 trailer. All layer 2 02051 (includes destination node address for routing), RDMA address 02051 for STPI in the destination node, RDMA address 02054 for DFoNP in the destination node, layer 3 02052 and layer 4 02053 information are in STPI. The DFoNP contains no layer 3 and 4 information. In this network, layer 2 02031 02041 contains frame type and hence, no additional field for frame type is present. DFoNP contains layer 2 header 02031 with next hop node address. STPI contains the node number 02055 and an index 02056 to the array containing the corresponding DFoNP. When DFoNP is transmitted to the next node, the node number 02055 and the index 02056 in the corresponding STPI are updated. STPI also contains Source Node Number 02057 (the node number of the node which created the STPI) and STPI sequence number 02058 . The STPI 02042 02043 is the only STPI in the STPI Frame. [0061] iii) FIG. 2C illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. All layer 3 02081 and layer 4 02082 information are in STPI and the DFoNP contains all 02061 layer 2 information. In this network, switches use 02081 layer 3 address to find next hop port. So 02071 layer 2 of STPI Frame does not have next hop node address. Frame Type in the frame gives the type of frame, DFoNP 02062 , STPI 02072 , etc. There are 2 STPIs 02073 in the STPI Packet and the first STPI 02074 corresponds to DFoNP. STPI contains the DFoNP Current Node Port Number 02083 corresponding to the node containing DFoNP and an offset 02084 in a buffer to the current location of the corresponding DFoNP. The port number 02083 is the port number on the switch containing STPI. When DFoNP is transmitted to the next node, the port number 02083 and offset 02084 in the corresponding STPI are updated. The port number 02083 is also updated-when STPI is transmitted to the next node. STPI also contains Source Node Number 02085 and a sequence number 02086 . [0062] iv) FIG. 2D illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains layer 3 02112 , layer 4 02113 , and part of layer 2 02111 protocol information (including route to the destination), RDMA address 02111 for STPI in the destination node. DFoNP contains data 02093 , part of layer 2 protocol information 02091 02096 and RDMA address 02091 for the DFoNP in the destination node. STPI contains 02115 DFoNP length and the port number 02114 and the buffer address 02115 to the location of the corresponding to DFoNP. When DFoNP is transmitted to the next node, the port number 02114 is reset (as DFoNP is in the same node) and buffer address 02115 in the corresponding STPI are updated. DFoNP Port number 02114 is also updated when STPI is transmitted to the next node. Both STPI and DFoNP contains originating node number 02116 02094 and STPI sequence number 02117 02095 . The address in the datalink header 02101 of the STPI Frame is the final destination node address in the subnet indicating all STPIs in the STPI Frame are to the same final destination and switching can be done using STPI Frame address. Frame Type in the frame gives the type of frame, DFoNP 02092 , STPI 02102 , etc. STPI Frame does not contain the number of STPIs as STPIs are of fixed length and the number of STPIs can be derived from the length of STPI frame. The first STPI 02103 in the frame corresponds to the DFoNP shown. [0063] v) FIG. 2E illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains part of 02143 layer 2 (Layer 2 in STPI contains destination address used for routing), RDMA address 02143 for STPI in the destination node, 02144 part of layer 3 information and all of 02145 layer 4 information. The DFoNP contains 02121 layer 2 protocol information, RDMA address 02121 for DFoNP in the destination node and 02123 part of layer 3 information. Frame Type in the frame gives the type of frame, DFoNP 02122 , STPI 02132 , etc. STPI corresponding to the DFoNP shown is the first STPI 02133 in the STPI Frame. STPI contains the current node number 02146 and index 02147 to the location of the corresponding to DFoNP. When DFoNP is transmitted to the next node, the node number 02146 and index 02147 in the corresponding STPI are updated. STPI also contains Source Node Number 02141 , STPI Sequence Number 02142 and miscellaneous 02148 information. The layer 2 header 02131 of the STPI frame contains next hop node address. [0064] vi) FIG. 2F illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. The network medium does not support layer 1 header or trailer. STPI contains part of layer 2 02173 (including destination node identifier used for routing) and part of layer 3 02174 protocol information. DFoNP contains layers 2 02151 , part of layer 3 02153 and all of layer 4 02154 protocol information. STPI contains the buffer address 02175 and an index 02175 in the buffer to the location of the corresponding to DFoNP. When DFoNP is transmitted to the next node, buffer address 02175 and offset 02175 in the corresponding STPI are updated. STPI also contains Source Node Number 02171 , STPI sequence number 02172 and miscellaneous 02176 information. Frame Type in the frame gives the type of frame, DFoNP 02152 , STPI 02162 , etc. The STPI Frame contains length 02163 of STPIs and since STPIs of this network are of fixed length, the position of the STPIs in the frame can be determined by the switch. Expanded view of the second STPI 02164 in the STPI frame is shown. The layer 2 header 02161 of the STPI frame contains next hop node address. [0065] vii) FIG. 2G illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. The network medium does not support layer 1 header or trailer. STPI contains part of layer 2 02203 (including destination node address for routing), part of layer 3 02204 and part of layer 4 02202 protocol information. DFoNP contains layer 2 02181 , part of layer 3 02183 and part of layer 4 02184 protocol information. STPI contains the current node number 02205 , an index to a buffer 02206 and an offset 02206 in the buffer to the location of the corresponding DFoNP. When DFoNP is transmitted to the next node, the node number 02205 , the index 02206 and the offset 02206 in the corresponding STPI are updated. STPI also contains the Source Node Number 02201 and miscellaneous 02207 information. Frame Type in the frame gives the type of frame, DFoNP 02182 , STPI 02192 , etc. The STPI Frame contains length 02193 of STPIs and since STPIs of this example are of fixed length, the position of the STPIs in the frame can be determined by the switch. Expanded view of the second STPI 02194 in the frame is shown. The layer 2 header 02191 of the STPI frame contains next hop node address. [0066] viii) FIG. 2H illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains part of layer 2 02233 (including destination node address for routing) and all of layer 3 02234 protocol information. The DFoNP contains layer 2 02211 and layer 4 02213 protocol information. STPI contains the length 02235 of the corresponding DFoNP and the current node identifier 02235 , buffer address 02236 and an offset 02236 in a buffer to the location of the corresponding DFoNP. When DFoNP is transmitted to the next node, the Current Node identifier 02235 , buffer address 02236 and the offset 02236 in the corresponding STPI are updated. STPI also contains Source Node Number 02231 and STPI Sequence Number 02232 . Frame Type in the frame gives the type of frame, DFoNP 02212 , STPI 02222 , etc. The STPI Frame in this example is allowed to have only one STPI 02222 . The layer 2 header 02221 of the STPI frame contains next hop node address. Expanded view of the STPI is shown. [0067] ix) FIG. 21 illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. The network supports protocol layers 5 , 6 and 7 in addition to lower layers. STPI contains 02263 layer 2 and 02264 layer 3 information. The DFoNP contains minimal layer 2 02241 protocol information allowed by the datalink layer, layer 4 , layer 5 , layer 6 , and layer 7 02243 protocol information. STPI contains the current node number 02265 , a buffer address 02266 in the node and an offset 02266 in the buffer to the location of the corresponding DFoNP. When DFoNP is transmitted to the next node, the node number 02265 , the buffer address 02266 and the offset 02266 in the corresponding STPI are updated. STPI also contains Source Node Number 02261 and STPI sequence number 02262 . Frame Type in the frame gives the type of frame, DFoNP 02242 , STPI 02252 , etc. The STPI Frame in this example is allowed to have only one STPI 02253 and 02251 layer 2 of the STPI frame contains address of the destination node in the subnet which is used for routing the STPI frame. Expanded view of the STPI is shown. [0068] x) FIG. 2J illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains layer 2 02293 protocol information (including destination node address for routing). The DFoNP contains 02271 part of layer 2 and all of layer 3 and layer 4 02273 protocol information. Frame Type in the frame gives the type of frame, DFoNP 02272 , STPI 02282 , etc. The STPI[ 1 ] 02284 is the only STPI 02283 in the STPI Frame. STPI contains the current node number 02294 and the buffer address 02295 in the node to the location of the corresponding DFoNP. When DFoNP is transmitted to the next node, the node number 02294 and the buffer address 02295 in the corresponding STPI are updated. STPI also contains Source Node Number 02291 and STPI Sequence Number 02292 . DFoNP contains Source Node Number 02274 and a DFoNP sequence number 02275 which is different from STPI sequence number. The layer 2 header 02281 of the STPI frame contains next hop node address. Expanded view of the STPI[ 1 ] is shown. [0069] xi) FIG. 2K illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains layer 2 02323 information (including destination node address for routing). The DFoNP contains minimal layer 2 02301 mandated by datalink layer of the subnetwork and all of layer 3 and 4 02302 information. The DFoNP contains control data 02323 such as requests to open a file in addition to data 02323 . In this network, layer 2 02301 02311 protocol information contains frame type and hence, no additional field for frame type is present. The STPI[ 1 ] 02313 is the only STPI 02312 in the STPI Frame. STPI contains the length 02324 of the corresponding DFoNP and the node number 02324 and the buffer address 02325 in the node to the location of the corresponding to DFoNP. When DFoNP is transmitted to the next node, the node number 02324 and buffer address 02325 in STPI are updated. STPI also contains the Source Node Number 02321 and STPI sequence number 02322 . DFoNP contains Source Node Number 02304 and a DFoNP Sequence Number 02305 which is different from STPI sequence number. Expanded view of STPI[ 1 ] is shown. [0070] xii) FIG. 2L illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains layer 2 02354 (including destination node address for routing) and layer 3 information 02353 and part of layer 5 / 6 / 7 02357 protocol information. The DFoNP contains minimal layer 2 Header 02331 mandated by datalink layer of the subnet, layer 4 02333 and part of layer 5 / 6 / 7 02334 protocol information. The DFoNP contains control data 02335 such as requests to open a file in addition to data 02335 . Frame Type in the frame gives the type of frame, DFoNP 02332 , STPI 02342 , etc. The STPI[ 1 ] 02344 is the only STPI 02343 in the STPI Frame. STPI contains the node number 02355 and buffer address 02356 in the node to the location of the corresponding DFoNP. When DFoNP is transmitted to the next node, the node number 02355 and buffer address 02356 in the corresponding STPI are updated. STPI also contains the Source Node Number 02351 and STPI sequence number 02352 . The layer 2 header 02341 of the STPI frame contains next hop node address. Expanded view of the STPI[l] 02344 is shown. [0071] xiii) FIG. 2M illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains layer 2 02386 (including destination node identifier used for routing), layer 3 02385 and layers 5 / 6 / 7 02387 protocol information. The DFoNP contains layers 2 02361 , layer 3 02363 and layer 4 02364 protocol information. Frame Type in the frame gives the type of frame, DFoNP 02362 , STPI 02372 , etc. STPI frame contains two STPIs 02373 and expanded view of the 2 nd STPI (STPI[ 2 ]) 02376 is shown. The STPI frame contains offsets 02374 to all STPIs in the frame. The network in this example supports more than one length for STPIs. STPI[ 1 ] offset 02374 gives the location of the first STPI (STPI[l] 02375 ) in the STPI frame. STPI[ 2 ] offset 02374 gives the location of the second STPI in the STPI frame. Offsets in this example are with respect to beginning of the frame. STPI contains the node number 02381 and buffer address 02382 in the node to the location of the corresponding DFoNP. When DFoNP is transmitted to the next node, the node number 02381 and buffer address 02382 in STPI are updated. STPI also contains Source Node Number 02383 and STPI sequence number 02384 . The layer 2 header 02371 of the STPI frame contains next hop node address. [0072] xiv) FIG. 2N illustrates example formats for DFoNP, the corresponding STPI and an STPI frame which contain STPIs. STPI contains layer 2 02415 (including destination node identifier used for routing) protocol information. The DFoNP contains layer 2 02391 , layers 3 02394 and layer 4 02394 protocol information. Frame Type in the frame gives the type of frame, Read Completion 02392 for DFoNP frame and Write 02402 for STPI frame. The STPI Frame contains the length of write 02403 (which is the length of STPI[ 1 ] 02403 and STPI[ 2 ] 02404 ) and address 02403 for the write. DFoNP contains Read Requester ID 02393 (Identifier) and a tag 02393 to identify the read request. DFoNP also contains address 02393 from which the layer 3 / 4 headers and the data 02395 is read and the length 02393 of the the read. The STPI Frame contains two STPIs and expanded view of the 2nd STPI (STPI[ 2 ]) 02404 is shown. STPI contains the node number 02411 and buffer address 02412 in the node to the location of the corresponding DFoNP and the length of the DFoNP 02416 . These information are used to read the corresponding DFoNP. When DFoNP is transmitted to the next node, the node number 02411 and buffer address 02412 in STPI are updated. STPI also contains Source Node Number 02413 , STPI Sequence Number 02414 and Miscellaneous 02416 information. The layer 2 header 02401 of the STPI frame contains next hop node address. [0073] Below five options for transferring STPI and the corresponding DFoNP from one node to another, are described. One of the first 4 methods can be used for transferring STPI and the corresponding DFoNP from the originating node or a switch to another switch or end node. The fifth method can be used for transferring STPI and the corresponding DFoNP to a destination end node: [0074] i) FIG. 3 illustrates one of the options that could be used in a given network for transmitting STPI and DFoNP to the next hop node. In this option a switch/node responds to Read-STPI request by transmitting STPIs. The switch/node receiving STPIs sends Read-DFoNP requests using the information contained in STPIs to fetch the corresponding DFoNPs. A frame containing a Read-STPI request is called Read-STPI Frame. A frame containing Read-DFoNP requests is called Read-DFoNP Frame. In FIG. 5A , Switch/Node A 03001 contains an STPI 03003 and the corresponding DFoNP 03004 to be transmitted to the Switch/Node B 03002 . In FIG. 3A , the Switch/Node B transmits Read-STPI Frame 03005 to the Switch/Node A giving the maximum number of STPIs that can be transmitted. The maximum number of STPIs 03005 are 5 in the example. In FIG. 3B , the Switch/Node A responds by sending an STPI frame 03011 containing the STPI 03003 (the STPI frame in this example can contain upto 5 STPIs). In FIG. 3C , the Switch/Node B decides to fetch the DFoNP corresponding to the STPI 03003 and sends Read-DFoNP Frame 03021 to the Switch/Node A containing the Read-DFoNP request for the DFoNP 03004 . The Read-DFoNP request contains the location (a location could be a buffer address or an offset in a buffer or an index or a combination of addresses, offsets or indexes) of the DFoNP 03004 in the Switch/Node A. The location of the DFoNP to be used in Read-DFoNP request will be present or can be derived from the contents of the corresponding STPI 03003 . In FIG. 3D , the Switch/Node A responds to the Read-DFoNP request for the DFoNP by sending the DFoNP 03004 . In FIG. 3E , the STPI 03003 is updated with the identifier of the Switch/Node B and the location of the DFoNP 03004 in the Switch/Node B. [0075] ii) FIG. 4 illustrates another option for transmitting STPI and the corresponding DFoNP to the next hop node. In this option, a switch/node transmits STPIs followed by DFoNPs corresponding to the STPIs transmitted. In FIG. 5A Switch/Node A 04001 contains an STPI 04003 and the corresponding DFoNP 04004 to be transmitted to the Destination Node B 04002 . In FIG. 4B , the Switch/Node A transmits an STPI Frame 04011 containing the STPI 04003 to the Switch/Node B. In FIG. 4C , the Switch/Node A transmits the DFoNP 04004 to the Switch/Node B. In FIG. 4D , the Switch/Node B updates the STPI 04003 with the location of the DFoNP 04004 in the Switch/Node B. [0076] iii) FIG. 5 illustrates another option for transmitting STPI and the corresponding DFoNP to the next hop node. In this option a switch/node transmits STPIs and the switch/node receiving STPIs sends Read-DFoNP requests using information contained in STPIs to fetch the corresponding DFoNPs. In FIG. 5A Switch/Node A 05001 contains an STPI 05003 and the corresponding DFoNP 05004 to be transmitted to the Switch/Node B 05002 . In FIG. 5B Switch/Node A transmits a frame 05011 containing the STPI to the Switch/Node B. In FIG. 5C , the Switch/Node B decides to fetch the DFoNP corresponding to the STPI and sends Read-DFoNP Frame 05021 to the Switch/Node A containing DFoNP request for the DFoNP 05004 . The DFoNP request contains the location of the DFoNP 05004 . The location of the DFoNP used in the Read-DFoNP request will be present or can be derived from the contents of the corresponding STPI 05003 . In FIG. 5D , the Switch/Node A responds to the Read-DFoNP request by transmitting the DFoNP 05004 . In FIG. 5E , the STPI 05003 is updated with identifier of Switch/Node B and the location of the corresponding DFoNP 05004 in the Switch/Node B. [0077] iv) FIG. 6 illustrates another option for transmitting STPI and DFoNP to the next hop node. In this option a switch/node responds to Read-STPI request by transmitting STPIs followed by the corresponding DFoNPs. In FIG. 6A Switch/Node A 06001 contains an STPI 06003 and the corresponding DFoNP 06004 to be transmitted to the Switch/Node B 06002 . The Switch/Node B transmits Read-STPI Frame 06005 to the Switch/Node A giving the maximum number of STPIs that can be transmitted. The maximum number of STPIs 06005 is 0 in the example indicating that all STPIs can be transmitted. In FIG. 6B , the Switch/Node A responds by sending an STPI frame 06011 containing all STPIs to be transmitted to the Switch/Node B. In FIG. 6C , the Switch/Node A transmits the DFoNP 06004 corresponding to the STPI to the Switch/Node B. In FIG. 6D , the STPI 06003 is updated with identifier of the Switch/Node B and the location of the corresponding DFoNP 06004 in the Switch/Node B. [0078] v) FIG. 7 illustrates an option which can be used for transmitting DFoNP and optionally the corresponding STPI from a switch/node to a destination node: In this option DFoNP is transmitted to the destination node and then optionally, the corresponding STPI is transmitted. In FIG. 7A , Switch/Node A 07001 contains an STPI 07003 and the corresponding DFoNP 07004 to be transmitted to the Destination End Node B 07002 . In FIG. 7B , Switch/Node A transmits the DFoNP 07004 to the Destination End Node B and updates the STPI 07003 with the location (DMA address) of the DFoNP in the Destination End Node B. In FIG. 7C , Switch/Node A transmits the STPI in an STPI frame 07021 to the Destination End Node B. In FIG. 7D , both STPI 07003 and DFoNP 07004 are received by End Node B. [0079] A switch can employ one of the STPI and DFoNP transfer options (strategies) listed above, for each port. Both ports on a point-to-point link must agree to the same frame transmitting option. All ports on a link or bus must follow the same frame transmitting option. Preferably, a network employs only one of the four STPI/DFoNP transfer options listed in FIG. 3 , FIG. 4 , FIG. 5 and FIG. 6 . Preferably, a network also employs the STPI/DFoNP transfer option listed in FIG. 7 . For the option corresponding to FIG. 7 , updating STPI with address (location) of DFoNP in the end node is optional. [0080] If DFoNPs do not contain information (such as originating node identifier, DFoNP identifier, DFoNP address in previous node, etc.) that allow a DFoNP to be mapped to the corresponding STPI, then the DFoNPs must be transmitted in the same order as requested in Read-DFoNP frame/s with design options listed in FIG. 3 and FIG. 5 . With design options listed in FIG. 4 and FIG. 6 , if DFoNPs do not contain information that allow the DFoNP to be mapped to the corresponding STPI, DFoNPs must be transmitted in the same order as the corresponding STPIs are transmitted. This will allow switches to identify STPI corresponding to an DFoNP that is received. [0081] There are a very large number of design options with network component designers with respect to the format of Read-STPI request and Read-STPI Frames containing Read-STPI request. FIG. 8 illustrates some examples of different formats in which the Read-STPI Frames can be created adhering to this invention. Preferably a given network employs only one format (design option) for Read-STPI request to keep the design of switches and end nodes simple. [0082] i) FIG. 8A illustrates a Read-STPI frame with Frame Type [0083] “Read-STPI” 08001 and “Number of STPIs” 08002 set to 3. The frame also contains Miscellaneous 08003 field. [0084] ii) FIG. 8B illustrates a Read-STPI frame in a network where explicit frame type specification is not required. The frame specifies an address 08011 for read (the location of the STPIs) in the node receiving the Read-STPI Frame. The frame also provides the length 08012 for read. The address where STPIs are stored can be dynamically configured on the switch for each node/switch it is connected to. [0085] iii) FIG. 8C illustrates a Read-STPI frame in a network without layer 1 headers or trailers. Frame Type 08021 is “Read-STPI”. The “Number of STPIs” 08022 is 0 indicating permission to transmit an STPI Frame with as many STPIs for the node transmitting Read-STPI Frame as possible, from the node receiving the Read-STPI Frame. The frame also contains a Miscellaneous 08023 field. [0086] iv) FIG. 8D illustrates a Read-STPI frame in a network without layer 1 headers or trailers. Layer 2 header 08031 contains Frame Type (Read-STPI). The “Number of STPIs” 08032 is −1 indicating permission to transmit all STPIs for the node transmitting Read-STPI Frame, from the node receiving the Read-STPI Frame. [0087] A Read-DFoNP Frame contains one or more Read-DFoNP requests and each Read-DFoNP request contains the location of the requested DFoNP. There are a very large number of design options with network component designers with respect to the format of Read-DFoNP requests and Read-DFoNP Frames containing Read-DFoNP requests. FIG. 9 illustrates some examples of different formats in which the Read-DFoNP Frame can be created adhering to this invention. Preferably, a given network employs only one format (design option) for Read-DFoNP request to keep the design of switches and end nodes simple. [0088] i) FIG. 9A , illustrates a Read-DFoNP frame with Frame Type 09001 “Read-DFoNP” and “Number of Read-DFoNP requests” 09002 set to 2 . The DFoNP[ 1 ] 09003 and DFoNP[ 2 ] 09004 buffer addresses provide the location of the DFoNPs in the node receiving the Read-DFoNP Frame. The frame also contains Miscellaneous 09005 field. [0089] ii) FIG. 9B illustrates a Read-DFoNP frame in a network where explicit frame type specification is not required. Frame specifies an address 09011 for read (the location of the DFoNP) in the node receiving the Read-DFoNP Frame. The frame also provides the length 09012 for read. [0090] iii) FIG. 9C illustrates Read-DFoNP frame in a network without layer 1 headers or trailers. Frame Type 09021 is “Read-DFoNP”, the “Number of Read-DFoNP requests” 09022 is 3. Each Read-DFoNP request contains a buffer address and an offset. The DFoNP[ 1 ] 09023 , DFoNP[ 2 ] 09024 and DFoNP[ 3 ] 09025 buffer addresses and offsets provide the location of the DFoNPs in the node receiving the Read-DFoNP Frame. [0091] iv) FIG. 9D illustrates a Read-DFoNP feame in a network without layer 1 headers or trailers. Frame Type (Read-DFoNP) is contained in layer 2 header 09031 . Only one Read-DFoNP request 09032 is allowed in the frame and the the Read-DFoNP request gives the index of the DFoNP to be read. [0092] Optionally, a switch or node can send the number of STPIs available for transmission to the next hop node or switch. There are a very large number of design options with network component designers with respect to the format of Number-of-STPIs message and Number-of-STPIs Frames containing Number-of-STPIs message. FIG. 10 illustrates some examples of different formats in which the Number-of-STPIs Frame can be created adhering to this invention. Preferably a given network employs only one format for Number-of-STPI message to keep the design of switches and end nodes simple. [0093] i) FIG. 10A , illustrates a Number-of-STPIs frame with Frame Type 10001 “Number-of-STPIs” and “Number of STPIs” 10002 set to 3. The frame also contains a Miscellaneous 10003 field. [0094] ii) FIG. 10B illustrates Number-of-STPIs frame in a network where explicit frame type specification is not required. Frame specifies an address 10011 to the location where value of Number of STPIs will be written and the length 10012 of the field to be written. The next field contains data (Number of STPIs) 10013 for the write, which is 2. [0095] iii) FIG. 10C illustrates Number-of-STPIs frame in a network without layer 1 headers or trailers. Frame Type 10021 is “Number-of-STPIs”. The “Number of STPIs” 10022 is 3. The frame also contains a Miscellaneous 10023 field. [0096] iv) FIG. 10D illustrates a Number-of-STPIs frame in a network without layer 1 headers or trailers. Layer 2 header 10031 contains Frame Type (Number-of-STPIs). The “Number of STPIs” 10032 is 1. [0097] The network described in this invention can be connected to an I/O card (in a server or embedded system) or to a PCI bus. [0098] i) The switch corresponding to this invention can be connected to an Ethernet card. a) A recommended frame format for use with Ethernet is as follows: 1) Ethernet header contains destination MAC: The network can use next hop MAC address in the STPI/DFoNP/Read-STPI/Read-DFoNP/Number-of-STPIs frame. 2) Ethernet header contains source MAC address: A DFoNP frame can contain the MAC address of the originating node in this field. All other types of frames (STPI, Read-STPI, Read-DFoNP, Number-of-STPI) can contain MAC address of the node transmitting the frame in this field. 3) The Ethernet header contains length field as per Ethernet Protocol standard. 4) The first byte of the data field contains the “Frame-Type”: one bit each for STPI, DFoNP, Read-STPI, Read-DFoNP and Number-of-STPIs. 5) Each STPI will contain the final destination MAC address. Optionally, each STPI can also contain source MAC address of the the originating node of the STPI. 6) The formats specified examples such as FIG. 2A , FIG. 2C etc., can be used with Ethernet. 7) The Ethernet trailer contains FCS for the frame. b) FIG. 11A illustrates an example of DFoNP and STPI frames which can be used with Ethernet. FIG. 11B illustrates Read-DFoNP frame which can be used with Ethernet. 1) Destination MAC address 11001 in DFoNP frame is the MAC address corresponding to the port or node (next hop node) receiving the frame. If switches are designed to ignore Destination MAC address in a DFoNP frame, the final destination node MAC address could be used in the Destination MAC address field. 2 ) Source MAC address 11002 in the DFoNP frame is the MAC address of the node that created the DFoNP. 3) The length field 11003 provides the length as per Ethernet Protocol standard. 4) The first field in the data portion of Ethernet Frame is Frame Type 11004 and Frame Type of DFoNP frame is DFoNP (DFoNP bit is set). 5) The DFoNP contains layer 3 11005 , layer 4 11006 protocol information and data 11007 . 6) Destination MAC address 11011 in the STPI frame is the MAC address corresponding to the port or node (next hop node) receiving the frame. 7) Source MAC address 11012 in the STPI frame is the MAC address corresponding to the port transmitting the frame. 8) The length field 11013 provides the length as per Ethernet Protocol standard. p9) The first field in the data portion of the Ethernet Frame is Frame Type 11014 and Frame Type of STPI frame is STPI (STPI bit is set). 10) The STPI frame in this example contains 2 STPIs 11015 . 11) Expanded view of the second STPI 11016 is shown. 12) Each STPI contains the Final Destination MAC address 11021 for the STPI and the corresponding DFoNP. Switches can use this address for routing. 13) The STPI contains the Source MAC Address 11022 of the Ethernet port through which the STPI entered the Ethernet LAN. 14) STPI contains “Destination STPI Address” 11023 which is the address to be used for RDMA Writing the STPI in the destination node. 15) STPI contains “Destination DFoNP Address” 11024 which is the address to be used for RDMA Writing the corresponding DFoNP in the destination node. 16) The STPI contains the MAC address of the node containing DFoNP 11025 , buffer address 11026 of the DFoNP in this node and length 11026 of the DFoNP. These fields are used to create Read-DFoNP request. 17) After an STPI an STPI frame is received, the next hop node can initiate read for the corresponding DFoNP. FIG. 11B illustrates a Read-DFoNP frame containing 3 Read-DFoNP requests. 18) The destination MAC address 11031 in the Read-DFoNP frame is the “DFoNP Current Node MAC address” 11025 from the STPI. 19) The source MAC address in the Read-DFoNP frame is the MAC address corresponding to the port transmitting the Read-DFoNP Frame. 20) The length field 11013 provides the length as per Ethernet Protocol standard. 21) The first field in the data portion of the Ethernet Frame is Frame Type 11034 and Frame Type of Read-DFoNP frame is “Read-DFoNP” (“Read-DFoNP” bit is set). 22) The Number of DFoNPs 11035 being requested from the node receiving Read-DFoNP frame is 3 in this example. 23) The DFoNP buffer address 11036 and the length 11036 of DFoNP in Read-STPI frame are from DFoNP Current Buffer Address 11026 and DFoNP Length 11026 fields in STPI. ii) If the switch corresponding to this invention is connected to a PCI bus, it behaves like an end node. The switch will use PCI transactions to communicate with the server. a) The host (in turn the PCI root bridge) can use PCI memory write transaction to transfer STPIs to a switch corresponding to this invention OR the switch can use PCI memory read transaction to read STPIs. The host can use PCI memory write transaction to write the address of the memory location holding STPIs which the switch can use for PCI Memory Read transaction. b) The switch can use PCI read transaction to read each DFoNP using the buffer address contained in the corresponding STPI. c) The host (in turn the PCI root bridge) can optionally use PCI write transaction to write the number of STPIs to a switch corresponding to this invention. d) The switch can use PCI memory write to write DFoNPs and STPIs to the memory of the destination node. e) FIG. 12 illustrates an example of transaction formats which can be used within PCI Express™ (PCI Express™ is a trade mark of PCI-SIG) transactions for transferring STPIs and DFoNPs from root bridge to a switch corresponding to this invention and vice versa. 1) Example in FIG. 12A illustrates format of PCI Express Read Completion containing DFoNP, from a root bridge in response to a Memory Read request from a switch. The first field of PCI Express Read Completion data provides the Frame Type 12001 which is DFoNP. The rest of the Read Completion data is layer 3 / 4 protocol information 12002 and Data 12003 being transmitted to the remote node. 2) Example in FIG. 12B illustrates format of PCI Express Read Completion containing STPIs, from a root bridge in response to a Memory Read request from a switch. The first field of data provides the Frame Type 12011 which is STPI. The second field in data is “Number of STPIs” 12012 which is 3 followed by three STPIs 12013 . Each STPI contains “Final Destination Node Identifier” 12021 which is used by switches for routing, Source Node Identifier 12022 which is the identifier of the node that created the STPI, “Destination STPI Address” 12023 to be used for RDMA Writing STPI in the destination, “Destination DFoNP Address” 12024 to be used for RDMA Writing the corresponding DFoNP in the destination, “DFoNP Current Node ID” 12025 , DFoNP Length and DFoNP Current Address 12026 to be used for reading DFoNP from the node where it is currently stored. The DFoNP Length field 12026 is also used for RDMAing DFoNP to the memory of the destination node. 3) Example in FIG. 12C illustrates a PCI Express Memory Write transaction containing DFoNP, from a switch to a root bridge . The first field of PCI Express Memory Write transaction data provides the Frame Type 12031 which is DFoNP. The rest of the Read Completion data is layer 3 / 4 information 12032 and Data 12033 that arrived from the remote node. 4) Example in FIG. 12D illustrates a PCI Express Memory Write transaction containing STPIs, from a switch to a root bridge. The first field of PCI Express Memory Write data provides the Frame Type 12041 which is STPI. The second field in the data is “Number of STPIs” 12042 which is 2 followed by two STPIs 12043 . Each STPI contains “Final Destination Node Identifier” 12051 which is used by switch for routing, Source Node Identifier 12052 which is the identifier of the node that created the STPI, a miscellaneous field 12053 , “DFoNP Current Node Identifier” 12054 , DFoNP Current Buffer Address 12055 and DFoNP Length 12055 to be used for reading DFoNP from the node where it is currently stored. The DFoNP Length field 12055 is also used for doing PCI Express Memory Write transaction to the root bridge (DMAing DFoNP to the memory of the destination node). The DFoNP and STPI are DMAed into read buffers provided by the destination node. [0141] When destination address contained in an STPI is a Multi-cast and Broadcast address, both STPI and DFoNP are transmitted to all next hop nodes identified by the Multi-cast or Broadcast address. [0142] When STPI or DFoNP frames are corrupted or lost, switches and nodes may employ retransmission of the corrupted or lost frame. The retransmission policy and error recovery are link (example PCI) and vendor specific. [0143] Some networks allow more than one type of content to be present in the same frame. The types of contents are STPI, DFoNP, Read-STPI request, Read-DFoNP request and Number-of-STPIs message. i) FIG. 13A illustrates a frame containing both Number-of-STPIs message and Read-DFoNP requests. The Frame Type 13001 is a bit-OR of “Number-of-STPIs” and “Read-DFoNP”. The “Number of STPIs” 13002 is 5 indicating that there are 5 STPIs available to be transmitted to the receiving node. The “Number of DFoNPs” 13003 is 3 and the receiving node is expected to respond to the request by transmitting the three DFoNPs requested. ii) FIG. 13B illustrates a frame containing both Read-STPI request and Read-DFoNP requests. The Frame Type 13011 is a bit-OR of “Read-STPI” and “Read-DFoNP”. The “Number of STPIs” field 13012 is 2 and the “Number of DFoNPs” field 13013 is 3. The node receiving the frame is expected to respond with two STPIs and the three requested DFoNPs. [0146] FIG. 14 illustrates an example of reading DFoNPs in a different order compared to the order in which STPIs are received. In FIG. 3A , Switch A 14001 has 3 DFoNPs 14004 to be transmitted to Switch B 14002 . The Switch A forwards 3 STPIs corresponding to the DFoNPs in an STPI frame 14003 to Switch B. The Switch B has 10 STPIs in its queue 14006 for its link to node D. The switch B has no STPIs in its queue 14005 for its link to node C. In FIG. 14B , the switch identifies that STPI[ 1 ] and STPI[ 2 ] received are for node D and adds STPI[ 1 ] and STPI[ 2 ] to the queue 14006 for the node D. The Switch B delays reading DFoNP[ 1 ] and DFoNP[ 2 ] since there are a large of STPIs already queued for the node D. The Switch B identifies that STPI[ 3 ] received is for the node C and queues STPI[ 3 ] to the queue 14005 for the node C. The Switch B sends Read-DFoNP Frame 14013 to the Switch A with DFoNP[ 3 ] address. [0147] If STPI contains a priority or QoS field, a switch can use it for controlling the order in which DFoNPs are read. Similarly, a priority or QoS field in STPI or DFoNP could be used by switches or nodes to control the order in which STPIs are transmitted to the next node. [0148] A network corresponding to this invention could be used to connect a server or servers to storage devices (such as disks, disk arrays, JBODs, Storage Tapes, DVD drives etc.). iSCSI and iSER (iSCSI Extensions for RDMA) are examples in which SCSI commands and SCSI data are transmitted using networks technologies used for server interconnect. ADVANTAGES [0149] A switch can delay receiving DFoNP for paths which are already congested. [0150] A switch can read DFoNP corresponding to a lightly loaded link ahead of other DFoNPs and transmit STPI and DFoNP more quickly to the lightly loaded link improving link efficiency. [0151] A switch can delay reading DFoNPs based on QoS or priority field in STPI. [0152] A switch can optimize switch resources, memory and frame/packet queues as congestions are minimized by delaying DFoNPs for ports which are already congested. [0153] The switch can ensure higher throughput on all links by rearranging order in which DFoNPs are read.

Datalink frames or networking packets contain protocol information in the header and optionally in the trailer of a frame or a packet. We are proposing a method in which part of or all of the protocol information corresponding to a frame or a packet is transmitted separately in another datalink frame. The “Separately Transmitted Protocol Information” is referred to as STPI. The STPI contains enough protocol information to identify the next hop node or port. STPI can be used avoid network congestion and improve link efficiency. Preferably, there will be one datalink frame or network packet corresponding to each STPI, containing the data and the rest of the protocol information and this frame/packet is referred to as DFoNP. The creation of STPI and DFoNP is done by the originator of the frame or packet such as an operating system.

FIELD OF THE INVENTION [0001] This invention relates to power conditioning units (inverters) for use with photovoltaic (PV) modules for delivering ac power either directly to the mains (grid) utility supply or for powering mains (grid) devices directly, independently from the mains utility supply. More particularly the invention relates to improved techniques for manufacturing such inverters, and to inverters manufactured by these techniques. BACKGROUND TO THE INVENTION [0002] We have previously described a range of improved techniques for increasing reliability and efficiency in photovoltaic inverters (see, for example, WO2007/080429 and others of our published patent applications). [0003] We now particularly address problems which can arise with so-called microinverters. A microinverter is an inverter dedicated to one or a few PV panels, and may be defined as an inverter having a power rating suitable for connection to less than 10 or less than 5 panels (for example less than 1000 watts, often less than 600 watts) and/or as an inverter having a dc input voltage which is less than half a peak-to-peak voltage of the ac mains, more typically less than 100 volts dc or less than 60 volts dc. One of the advantages of a microinverter is that it can be physically located close to the PV panel or panels to which it is connected, thus reducing the voltage drop across the connecting cables (which can be significant). However, locating a microinverter adjacent to or on a PV panel brings other difficulties, in particular because such locations are subject to extreme temperature and environmental conditions including, for example, water, ice, humidity, and dry heat (depending upon the installation, up to or above 80° C.). [0004] The very large temperature excursions, and in particular the extremes of high temperature which may be encountered, create particular difficulties. In addition a microinverter generates heat which increases the internal temperature of the electronic components above the local ambient conditions. Simple potting of the electronic components can in principle help to address some of these issues but in practice air bubbles and the like can give rise to local temperature hotspots (caused by the low thermal conductivity of air), which can lead to reliability problems and premature failure of the inverter. [0005] There therefore exists a need for improved manufacturing techniques for solar photovoltaic inverters, in particular microinverters. SUMMARY OF THE INVENTION [0006] According to the present invention there is therefore provided a solar photovoltaic inverter, the inverter comprising: a power conditioning circuit mounted on a circuit board, the power conditioning circuit having a dc power input to receive dc power from one or more photovoltaic panels and an ac power output to deliver ac power to an ac mains power supply; an electrically conductive shield enclosing said circuit board; and a plastic overmould over said conductive shield and said circuit board; wherein said electrically conductive shield has one or more holes to allow said plastic overmould to extend through said shield to cover said circuit board. [0007] In embodiments the electrically conductive shield comprises a metal can having portions which fit opposite faces of the circuit board. In embodiments each portion has a flange which fits on, around or against a perimeter of the circuit board, so that the portions of the can clamp around the circuit board. The one or preferably more holes in the conductive shield (or can) enable the plastic, for example polyamide, overmould to be injection moulded over the combination of the circuit board and can. Thus the injection moulded plastic provides a sealed, solid plastic housing which encases the power conditioning circuit, the holes in the can enabling the plastic overmould to pass through the can to overmould the circuit board. The finished item is a robust, solid, sealed plastic unit, which is substantially free of air bubbles, and which provides a high degree of environmental protection. Furthermore the combined overmoulding and can arrangement facilitates the spreading and dissipation of heat from power components on the circuit board, helping to address the issues causing reliability problems. [0008] In some preferred implementations one or more of the magnetic components that is coils, transformers and the like, is/are pre-coated with an elastic material such as silicone. This is because such magnetic components, in particular the core of such components (often comprising a ceramic material), have a different coefficient of thermal expansion to the plastic or polymer overmould. Thus by providing a relatively soft, compressible material between the coil or transformer and the overmould, the core is able to thermally expand without cracking. In some preferred embodiments the power conditioning circuit includes an RF transmitter and/or receiver, for example to permit monitoring and/or control of the solar inverter (as described in our UK patent application number 1017971.1 filed 25 Oct. 2010). In this case, advantageously, the electrical shield can also be employed as an antenna. The shield may float or may be coupled to a ground connection of the power conditioning circuit by a reactive component or circuit, in particular which has low impedance at low frequencies and a high impedance at higher frequencies. When the shield or can is functioning as an antenna preferably the hole or holes in the shield/can have a maximum dimension which is less than a free space wavelength of an operating frequency of the RF transmitter/receiver. More preferably the maximum dimension is less than half a wavelength, most preferably less than a quarter wavelength. In embodiments the power conditioning unit includes a transceiver operating in the 2.45 GHz ISM (industrial, scientific, medical) band, for example a ZigBee™ device, in which case preferably a hole has a maximum dimension of no more than 35 mm. [0009] In some implementations of the technique, dc input and/or ac output cables are overmoulded by injection moulding together with the shield and circuit board. This can help reduce the risk of water ingress through the cables. However an alternative approach, in embodiments preferable, is to replace in particular the dc cable or cables by a modular connector system in which a first interface part is mounted on the circuit board and then overmoulded to leave what is, in effect, a standard interface to the microinverter. Then any of a set of second mateable interface parts may be mated with this first interface part to connect to the photovoltaic panel or panels. This is advantageous because there is at present no universal standard for dc connection to a PV panel or module, and thus were the dc cable or cables to be overmoulded multiple different inverter versions would be needed to interface with multiple different types of PV panel. Instead the aforementioned approach enables a common manufacturing procedure followed by a customisation of the device to interface to a particular panel or panels. [0010] Thus the inverter may be provided with a set of second interface parts each configured to provide a connection to a different type of photovoltaic panel. Additionally or alternatively the set of second interface parts may be configured to make connection with two or more PV panels of the same type, for example to provide the advantages described in our GB1009430.8 and U.S. Ser. No. 12/947,116 patent applications (incorporated by reference). Furthermore, because the first interface part is sealed by the overmould, there are no particularly stringent environmental requirements on the modular connector system since this is sealed at/behind the first interface to the circuit board. [0011] In some preferred embodiments the plastic overmould is also configured to define one or more mounting points for the inverter, for example to define a mounting plate and/or one or more tags, ears or the like optionally bearing mounting holes. [0012] in preferred embodiments the inverter is a microinverter, and is preferably configured for mounting behind or adjacent to the PV panel. [0013] In a related aspect the invention provides a method of manufacturing a solar photovoltaic inverter, the method comprising: providing a power conditioning circuit mounted on a circuit board, the power conditioning circuit having a dc power input to receive dc power from one or more photovoltaic panels and an ac power output to deliver ac power to an ac mains power supply; providing an electrically conductive shield enclosing said circuit board; and injection moulding a plastic overmould over said conductive shield and said circuit board; wherein said electrically conductive shield has one or more holes to allow said plastic overmould to extend through said shield to cover said circuit board. [0014] Preferred embodiments of the method further comprise pre-coating a coil or transformer of the inverter with an elastic material prior to the injection moulding, to make provision for thermal expansion of the core of the coil or transformer. [0015] Some preferred embodiments use the shield (or can) as an antenna for an RF communications circuit coupled to a microcontroller of the power conditioning circuit. In this case preferably the one or more holes are arranged so that they have a maximum dimension less than a wavelength, half wavelength or quarter wavelength of a frequency of operation of the RF circuit. [0016] As previously mentioned, In some preferred embodiments the dc power input of the circuit board is provided by a modular connector system for connecting to any of a set of photovoltaic panels (with either the same, or different, types of dc connections). [0017] In embodiments the modular connector system comprises a first interface part and a set of second interface parts to interface with the set of photovoltaic panels, the first part being mateable with any of the second parts. The method may then further comprise overmoulding the first interface part, selecting one or more second interface parts to connect to a PV panel, and then mating the selected second interface part or parts with the first interface part (or parts) subsequent to the overmoulding. [0018] In preferred embodiments the electrically conducted shield comprises a metal can having two parts within which the circuit board is sandwiched to, in combination with the overmoulding, spread and dissipate heat from one or more power components on the circuit board. Such power components may include, for example, one or more power semiconductor switching devices. [0019] In embodiments the overmoulding is used to mount the microinverter on or adjacent to a PV panel, and the injection moulded overmoulding is configured to provide a mounting plate or the like. [0020] In embodiments the injection moulding process comprises injecting the overmould plastic or polymer into an injection moulding tool in which the circuit board and conductive shield (and optionally connecting cables) are located, under pressure to expel air. BRIEF DESCRIPTION OF THE DRAWINGS [0021] These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures, in which: [0022] FIG. 1 shows an outline block diagram of an example power conditioning unit; [0023] FIGS. 2 a and 2 b show details of a power conditioning unit of the type shown in FIG. 1 ; [0024] FIGS. 3 a and 3 b show details of a further example of solar photovoltaic inverter; [0025] FIGS. 4 a and 4 b show an exploded views of solar photovoltaic inverters according to embodiments of the invention; [0026] FIG. 5 shows details of an antenna connection for the solar inverters of FIG. 4 ; and [0027] FIGS. 6 a and 6 b show, respectively, an example of an overmoulded solar photovoltaic inverter according to an embodiment of the invention, and elements of the inverter of FIG. 6 a prior to overmoulding. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Power Conditioning Units [0028] By way of background, we first describe an example photovoltaic power conditioning unit. Thus FIG. 1 shows photovoltaic power conditioning unit of the type we described in WO2007/080429. The power converter 1 is made of three major elements: a power converter stage A, 3 , a reservoir (dc link) capacitor C dc 4 , and a power converter stage B, 5 . The apparatus has an input connected to a direct current (dc) power source 2 , such as a solar or photovoltaic panel array (which may comprise one or more dc sources connected in series and/or in parallel). The apparatus also has an output to the grid main electricity supply 6 so that the energy extracted from the dc source is transferred into the supply. [0029] The power converter stage A may be, for example, a step-down converter, a step-up converter, or it may both amplify and attenuate the input voltage. In addition, it generally provides electrical isolation by means of a transformer or a coupled inductor. In general the electrical conditioning of the input voltage should be such that the voltage across the dc link capacitor C dc is always higher than the grid voltage. In general this block contains one or more transistors, inductors, and capacitors. The transistor(s) may be driven by a pulse width modulation (PWM) generator. The PWM signal(s) have variable duty cycle, that is, the ON time is variable with respect to the period of the signal. This variation of the duty cycle effectively controls the amount of power transferred across the power converter stage A. [0030] The power converter stage B injects current into the electricity supply and the topology of this stage generally utilises some means to control the current flowing from the capacitor C dc into the mains. The circuit topology may be either a voltage source inverter or a current source inverter. [0031] FIG. 2 shows details of an example of a power conditioning unit of the type shown in FIG. 1 ; like elements are indicated by like reference numerals. In FIG. 2 a Q 1 -Q 4 , D 1 -D 4 and the transformer form a dc-to-dc conversion stage, here a voltage amplifier. In alternative arrangements only two transistors may be used; and/or a centre-tapped transformer with two back-to-back diodes may be used as the bridge circuit. In the dc-to-ac converter stage, Q 9 , D 5 , D 6 and Lout perform current shaping. In alternative arrangements layout may be located in a connection between the bridge circuit and the dc link capacitor. Transistors Q 5 -Q 8 constitutes an “unfolding” stage. Thus these transistors Q 5 -Q 8 form a full-bridge that switches at line frequency using an analogue circuit synchronised with the grid voltage. Transistors Q 5 and Q 8 are on during the positive half cycle of the grid voltage and Q 6 and Q 7 are on during the negative half cycle of the grid voltage. [0032] Control (block) A of FIG. 1 may be connected to the control connections (e.g. gates or bases) of transistors in power converter stage A to control the transfer of power from the dc energy source. The input of this stage is connected to the dc energy source and the output of this stage is connected to the dc link capacitor. This capacitor stores energy from the dc energy source for delivery to the mains supply. Control (block) A may be configured to draw such that the unit draws substantially constant power from the dc energy source regardless of the dc link voltage V dc on C dc . [0033] Control (block) B may be connected to the control connections of transistors in the power converter stage B to control the transfer of power to the mains supply. The input of this stage is connected to the dc link capacitor and the output of this stage is connected to the mains supply. Control B may be configured to inject a substantially sinusoidal current into the mains supply regardless of the dc link voltage V dc on C dc . [0034] The capacitor C dc acts as an energy buffer from the input to the output. Energy is supplied into the capacitor via the power stage A at the same time that energy is extracted from the capacitor via the power stage B. The system provides a control method that balances the average energy transfer and allows a voltage fluctuation, resulting from the injection of ac power into the mains, superimposed onto the average dc voltage of the capacitor C dc . The frequency of the oscillation can be either 100 Hz or 120 Hz depending on the line voltage frequency (50 Hz or 60 Hz respectively). [0035] Two control blocks control the system: control block A controls the power stage A, and control block B power stage B. An example implementation of control blocks A and B is shown in FIG. 2 b . In this example these blocks operate independently but share a common microcontroller for simplicity. [0036] In broad terms, control block A senses the dc input voltage (and/or current) and provides a PWM waveform to control the transistors of power stage A to control the power transferred across this power stage. Control block B senses the output current (and voltage) and controls the transistors of power stage B to control the power transferred to the mains. Many different control strategies are possible. For example details of one preferred strategy reference may be made to our earlier filed WO2007/080429 (which senses the (ripple) voltage on the dc link)—but the embodiments of the invention we describe later do not rely on use of any particular control strategy. [0037] In a photovoltaic power conditioning unit the microcontroller of FIG. 2 b will generally implement an algorithm for some form of maximum power point tracking. In embodiments of the invention we describe later this or a similar microcontroller may be further configured to control whether one or both of the dc-to-dc power converter stages are operational, and to implement “soft” switching off of one of these stages when required. The microcontroller and/or associated hardware may also be configured to interleave the power transistor switching, preferable to reduce ripple as previously mentioned. [0038] Now to FIG. 3 a , this shows a further example of a power conditioning unit 600 . In the architecture of FIG. 3 a photovoltaic module 602 provides a dc power source for dc-to-dc power conversion stage 604 , in this example each comprising an LLC resonant converter. Thus power conversion stage 604 comprises a dc-to-ac (switching) converter stage 606 to convert dc from module 602 to ac for a transformer 608 . The secondary side of transformer 608 is coupled to a rectifying circuit 610 , which in turn provides a dc output to a series-coupled output inductor 612 . Output inductor 612 is coupled to a dc link 614 of the power conditioning unit, to which is also coupled a dc link capacitor 616 . A dc-to-ac converter 618 has a dc input from a dc link and provides an ac output 620 , for example to an ac grid mains supply. [0039] A microcontroller 622 provides switching control signals to dc-to-ac converter 606 , to rectifying circuit 610 (for synchronous rectifiers), and to dc-to-ac converter 618 in the output ‘unfolding’ stage. As illustrated microcontroller 622 also senses the output voltage/current to the grid, the input voltage/current from the PV module 602 , and, in embodiments, the dc link voltage. (The skilled person will be aware of may ways in which such sensing may be performed). In some embodiments the microcontroller 622 implements a control strategy as previously described. As illustrated, Microcontroller is coupled to an RF transceiver 624 such as a ZigBee™ transceiver, which is provided with an antenna 626 for monitoring and control of the power conditioning unit 600 . [0040] Referring now to FIG. 3 b , this shows details of a portion of an example implementation of the arrangement of FIG. 3 a . This example arrangement employs a modification of the circuit of FIG. 2 a and like elements to those of FIG. 2 a are indicated by like reference numerals; likewise like elements to those of FIG. 3 a are indicated by like reference numerals. In the arrangement of FIG. 3 b an LLC converter is employed (by contrast with FIG. 2 a ), using a pair of resonant capacitors C 1 , C 3 . [0041] The circuits of FIGS. 1 to 3 are particularly useful for microinverters, for example having a maximum rate of power of less than 1000 Watts and or connected to a small number of PV modules, for example just one or two such modules. In such systems the panel voltages can be as low as 20 volts and hence the conversion currents can be in excess of 30 amps RMS. Manufacturing Techniques [0042] We will now describe techniques which enable a solar microinverter to be encapsulated to provide a combination of thermal management, dielectric resistance, environmental robustness and good electromagnetic emissions performance. [0043] Referring now to FIGS. 4 a and 4 b , these show an exploded 3-D view of a solar photovoltaic inverter 400 according to an embodiment of the invention. The solar inverter comprises a power conditioning circuit, for example of the type shown in FIGS. 3 a and 3 b , mounted on a circuit board 402 , having, in the illustrated example, two dc power inputs 404 and an ac power output 406 , each comprising a cable connection to the circuit board 402 . The circuit board is provided with a conductive shield comprising first and second portions 408 a, b of a can which substantially encloses the circuit board 402 , fitting around the perimeter of the circuit board. The can may be formed, for example, from 0.8 mm-1 mm aluminium, and provides EMC (electromagnetic compatibility) shielding, as well as a thermal conductor for heat spreading/dissipation. [0044] Each of can portions 408 a, b is provided with a set of holes 410 (not visible in can portion 408 a ) and these enable the entire assembly to be overmoulded in an injection moulding process so that the encapsulation becomes the mechanical housing of the device. By providing holes 410 the encapsulating material is able to expel air from the assembly. This means that there is no condensation, no issues associated with thermal expansion of the air, and the injection moulding process ensures that there are no hot spots from residual air bubbles when the inverter is in use. [0045] The injection moulding process is performed in the usual way, by providing a suitable injection moulding tool within which the assembly to overmould is located, the overmoulding, for example of polyamide then being applied under pressure. The mould or tool may be shaped to enable the escape of air through air vents, for example in the parting line of the mould. [0046] The result is a plastic overmould 412 . In FIG. 4 , for ease of representation, this is not shown as extending through can portion 408 a but nonetheless in practice the overmould coats the circuit board 402 . Similarly for ease of representation the lower part of overmould 412 is not shown in FIG. 4 a . In the illustrated example overmould 412 includes strain relief features 412 a for cables 404 , 406 . The overmould process is able to provide a high degree of environmental sealing/protection, for example up to IP67 or IP68. A high degree of hermetic sealing is also useful where an inverter may need to have a long shelf life, to ensure that there is minimal moisture ingress. The circuit board 402 may include, for example, a transformer 402 a , and to prevent cracking of overmoulded core this is preferably pre-coated in silicone to allow for thermal expansion. [0047] FIG. 4 b shows another example of a solar photovoltaic inverter 450 , very similar to that of FIG. 4 a , according to an embodiment of the invention. Like elements to those of FIG. 4 a are indicated by like reference numerals. In the arrangement of FIG. 4 a the shielding and overmould are asymmetric with respect to the printed circuit board assembly 402 . Again not all of holes 410 are shown, and again the full extent of the plastic overmould is omitted, for clarity. [0048] In FIG. 4 b the base portion of overmould 412 comprises a base plate with locking features to match an interface base 414 , for mounting the inverter on a photovoltaic panel. Optionally the interface base 414 may be incorporated into the overmould 412 . [0049] The PCB assembly 402 of FIG. 4 b also includes a modular connector system 416 , comprising a connector plate which is overmoulded to form a seal behind the plate. This facilitates a manufacturing process in which standard form inverters are overmoulded and then afterwards cable connectors added for the photovoltaic panels by mating a suitable cable connector to the standard interface 416 of the modular connector system. [0050] In embodiments one or both can portions 408 a, b may be employed as the antenna 626 of the RF transceiver 624 of the FIG. 3 a . Referring to FIG. 5 , the antenna/shield may either be allowed to float or it may be grounded via an RF choke 502 making connection to a ground line 500 of the inverter. [0051] Where one or both of can portions 408 a, b is used as an antenna it is preferable that hole portions 410 have maximum dimension which is no greater than the wavelength at the frequency of operation of RF transceiver 624 , preferably no greater than a quarter wavelength so that the holes are effectively ‘invisible’ to the RF signal. In embodiments the RF transceiver 624 is a ZigBee™ (transceiver) operating at approximately 2.4 GHz, in which case the quarter wavelength dimension is 31.25 mm (although in practice this will be modified a little by the effect of the dielectric overmoulding of the can/antenna). [0052] Referring now to FIG. 6 a , this shows a further embodiment of an overmoulded solar photovoltaic inverter 700 , showing a view from above and two side elevations. The inverter 700 has a plastic overmould 702 , which forms the body of the inverter, into which is moulded a mounting plate 704 . (In alternative embodiments the mounting may be formed from the overmould itself. The inverter has a pair of cables 706 a,b for positive and negative dc connections to a photovoltaic panel, for example of standard MC4 type, and an ac mains output cable 706 bearing a suitable connector at the end. [0053] FIG. 6 b illustrates components of the inverter 700 prior to overmoulding, showing top and side views of the inverter 700 , cross-sectional views of top and bottom electrically conductive shield (Faraday cage) components 750 , 760 , and the mounting plate 704 . As can be, seen the Faraday cage incorporates a plurality of holes to enable the overmoulding to be performed after coating the circuit board with silicone or the like. [0054] No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.

The invention relates to improved techniques for manufacturing power conditioning units (inverters) for use with photovoltaic (PV) modules, and to inverters manufactured by these techniques. We describe a solar photovoltaic inverter, comprising: a power conditioning circuit mounted on a circuit board, the power conditioning circuit having a dc power input to receive dc power from one or more photovoltaic panels and an ac power output to deliver ac power to an ac mains power supply; an electrically conductive shield enclosing said circuit board; and a plastic overmould over said conductive shield and said circuit board; wherein said electrically conductive shield has one or more holes to allow said plastic overmould to extend through said shield to cover said circuit board.

BACKGROUND OF THE INVENTION 1. Field of the Invention A lamp swivel for pivotally or rotatably mounting a lamp body to a lamp base, so that the lamp body has an articulated mounting. 2. Description of the Prior Art Numerous configurations of lamps and other mountings for receiving an electric light bulb, or a fluorescent lamp, are known to the art. With especial regard to electric light bulbs, the usual table, desk or floor lamp includes a socket, having a switch, which is mounted in conjunction with a lamp harp to the body of the lamp, which in may cases extends directly to a lamp base which supports the entire article. The light bulb is screwed into the socket between the arms of the harp, and the lamp shade is suspended from the top of the harp by means of a spider or the like which has a plurality of radial arms. The spider arms radially extend from the center top of the harp to attachment to the upper edge of the lamp shade, so that the shade is suspended from the harp by a cantilever suspension as is commonly understood by those skilled in the art. In the usual conventional lamp configuration, the entire lamp structure must be moved and placed in a different location in order to change the source of light; and the origin of the light, relative to a desk or work table being illuminated, is not easily varied or changed. Swing arm lamps are known in which swivel connectors or coupling means provide an articulated mounting attachment. Among the prior art relative to lamp swivels and the like may be mentioned U.S. Pat. Nos. 4,175,809; 4,079,969; 4,042,262; 3,983,386; 3,957,331; 3,604,923; 3,022,096; 3,012,798; 2,729,473; 2,887,329; 2,694,585; 2,488,898; 1,609,230 and 1,492,335. OBJECTS OF THE INVENTION It is an object of the present invention to provide an improved lamp swivel. Another object is to provide a lamp swivel such that the lamp mounting is articulated. A further object is to provide an improved swing arm lamp. An additional object is to provide an improved lamp swivel connector and coupling means which provides an articulated mounting attachment for the lamp. An object is to provide a lamp swivel such that the origin or source of light, relative to a desk or work table or the like being illuminated, may be easily varied or changed. An object is to provide a lamp swivel which is cheaply and easily manufactured in mass production facilities using unskilled labor, and by the use of inexpensive materials of construction, e.g. inexpensive metals such as brass, bronze, copper, steel, aluminum which may be anodized, zinc die castings, etc., or a plastic such as bakelite, polyethylene, polypropylene especially isotactic polypropylene, polyvinyl chloride, nylon, teflon, methyl methacrylate or other acrylic resin, ABS, etc. Yet another object is to provide lamp swivel for a cantilever suspension of a lamp body. These and other objects and advantages of the present invention will become evident from the description which follows. BRIEF DESCRIPTION OF THE INVENTION The present invention basically entails the provision of a lamp swivel which is mountable between a lamp base and a lamp body, so that the lamp body together with its associated light-generating means may be swivelably pivoted and rotated on linear support means and about an axis. This axis is the principal axis of the lamp swivel, and as will appear infra, both main members of the lamp swivel are coaxial with this principal axis. The present lamp swivel basically includes a first member and a second member. The first member has a first central axis, and the second member has a second central axis. Typically, the first and second central axes are coaxial with the aforementioned principal axis. The first member is characterized by the provision of a main body disposed along the first central axis, and a cylindrical extension which depends from the main body of the first member. The extension is generally coaxial with the first central axis, and as mentioned supra the first central axis will generally lie along the principal axis. The first member body is provided with means to receive one end of the aforementioned linear support means. This linear support means extends from the one end to an other end connection to the lamp body. Pin means extends laterally outwards from the outer surface of the extension portion of the first member. Typically, the pin means basically includes a pin per se, together with the provision of a lateral pocket in the outer surface of the extension portion of the first member. The pin is detachably insertable into the pocket. Alternatively, the pin means can be an integral male protrusion or protuberance, or a discrete pin which is pressed into the pocket for semi-permanent installation. Typically the pin is cylindrical and the pocket is circular, and the pin is coaxially insertable into the pocket. The lamp swivel device and article of manufacture is completed in its most general configuration by the provision of a second member having a central axis generally designated herein as a second central axis. The second member has a body disposed along the second central axis. One end of this second member body has a cylindrical recess which is coaxial with the second central axis. The cylindrical recess has a diameter which is slightly greater than the diameter of the aforementioned cylindrical extension of the first member, so that the extension is contiguously insertable into the recess. The lateral surface of the recess has a slot and a circular groove. This surface slot extends from one end of the second member body to the circular groove in the surface of the recess. The groove is coaxial with the second central axis, so that when the extension is inserted into the recess, at least a portion of the first central axis is coaxial with the second central axis. The pin means then is receivable through the slot and into the groove, so that the first member is detachably attached to the second member, and so that the first, member is at least partially rotatable about its first central axis while the second member either remains stationary or concomitantly rotates about its second central axis, which as mentioned lies along the principal axis. Finally, the second member body is detachably attachable to a means, such as a lamp post or rod, this means extending to the lamp base. Typically, in a preferred embodiment, the first and second members are cylindrical and coaxial. It is preferred that the linear support means and the means extending to the lamp base each are laterally detachably receivable in and attachable to their respective first or second members. It is also preferred that the means in the first member body to receive one end of the linear support means, and the detachable attachment of the means extending to the lamp base, each include a threaded cylindrical recess or opening in the respective first or second member body. In this case, typically each recess or opening extends laterally into the respective first or second member body. In other preferred embodiments, and usually, the lamp body includes a lamp harp, a lampshade mounted to the lamp harp, and light-generating means, such as an electric-light bulb and socket, also mounted to the lamp harp. The light bulb is of course receivable into the socket. Typically, the outer surface portion of the second member body at or adjacent to the junction of the slot and the groove is coinable, i.e. composed of a coinable metal or alloy such as brass, bronze, copper, an aluminum alloy, a zinc alloy, a nickel alloy, stainless steel or wrought iron, so that when the pin means is inserted through the slot and into the groove, and the first member is rotated relative to the second member, so as to displace the pin means away from the slot, then the aforementioned outer surface portion is coinably stampable inwards, so that the pin means then cannot again be channeled by manipulation through the slot, and is permanently disposed in the groove. Thus, the first and second members are permanently attached to each other, and rotatable relative to each other by less than 360 degrees, about the aforementioned principal axis. Finally, in a preferred embodiment, each of the first and second members is provided with a central cylindrical through opening, each of these openings being coaxial with the respective member, with at least a portion of each of these openings being threaded. Thus in summary, the present invention provides a lamp swivel composed of two main coaxial members, which are at least partially rotatable relative to each other. An inner pin extends from one member to a circular inner groove in the other member, the groove being coaxial with the members; however, the other member, usually composed of a metal such as brass, copper or aluminum which may be anodized, is coined so as to prevent egress of the pin from the groove. Thus the two members are semi-permanently attached to each other and can rotate, by less than 360 degrees, relative to each other. The invention is especially applicable to provide an articulated lamp mounting for a swing arm lamp or the like, the lamp swivel being a swivel connector or coupling means which provides an articulated mounting attachment for the lamp. The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the device and article of manufacture hereinafter described, and of which the scope of application is as elucidated supra and as will be indicated in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings in which is shown one of the various possible embodiments of the invention: FIG. 1 is an overall perspective view of the present lamp swivel as installed between two lamp rods or posts which connect the lamp swivel to, respectively, a lamp body or socket, and a lamp base; FIG. 2 is an exploded sectional elevation view of the present lamp swivel; FIG. 3 is a bottom plan view of the upper portion of the lamp swivel of FIG. 2, taken substantially along the line 3--3 of FIG. 2; FIG. 4 is a top plan view of the lower portion of the lamp swivel of FIG. 2, taken substantially along the line 4--4 of FIG. 2; FIG. 5 shows the assembled lamp swivel in a sectional elevation view and prior to the final coining step which semipermanently secures the upper portion to the lower portion; and FIG. 6 shows the fully assembled and finished lamp swivel in a sectional elevation view and including the configuration, as shown, which includes the coining to secure the upper and lower portions of the swivel together. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, the present lamp swivel 10 includes an upper first member 12 and a lower second member 14. Linear support means 16, consisting in this case of a generally horizontally oriented lamp rod or post, extends between the upper member 12 of the lamp swivel 10 and a lamp body 18. The lamp body 18 may be of any suitable configuration and including an associated light-generating means, thus, in this case, the lamp body 18 includes a lower main body portion 20 into which a lamp socket 22 having a switch 24 is receivable, an electric light bulb 26, and a lampshade 28 mounted in this case directly to the bulb 26. One end 30 of the lamp rod or post 16 is received in the first member body 12, and the other end 32 of the member 16 is connected to the main body portion 20 of the lamp body 18. Thus, as will appear infra, the entire lamp body 18 assemblage is horizontally rotatable, as indicated by the doubleheaded arrow 34, about the vertical axis 36. In other words, the lamp body 18 together with its associated light-generating means 26 may be horizontally swivelably pivoted and rotated on the horizontal linear support means 16 and about the vertical axis 36, which axis 36 constitutes the principal axis of the lamp swivel, as will appear infra. FIG. 1 also shows a lamp base 38, which is mounted or supported on a fixed or semi-permanent support such as a floor, a table, a shelf, a desk, or the like, not shown. Means 40, consisting in this case of a linear support means, i.e. a generally horizontally oriented lamp rod or post, extends between the lower member 14 of the lamp swivel 10 and the upper portion 42 of the lamp base 38, which is horizontally pivotable relative to the stationary lower portion 44 of the lamp base 38, so that the second member 14, which may remain stationary in practice, may alternatively be concomitantly rotated about its axis, e.g. the principal axis 36, as will appear infra and as indicated by the double headed arrow 46; or, in most instances, second member 14 when rotated will rotate about central axis 48 of the lamp base 38. As will appear infra, one end 50 of the lamp rod or post 40 is detachably attached to the lower member 14, the member 40 constituting a means which extends from the second member 14 to the lamp base 38. FIG. 1, which constitutes the fully assembled lamp swivel 10, also shows the coined section 52 of the lower member 14, as well as a threaded cylindrical plug 54 which extends into a threaded top opening in upper member 12. Referring now to FIGS. 2, 3, and 4, salient details and elements of the lamp swivel are shown. With regard first to the upper member 12, this member 12 is characterized by having a central axis 55 which is aligned along the central axis 36, with a cylindrical body portion 56 being disposed along the axis 55. A cylindrical extension 58 depends coaxially from the body 56, and the axis 55 of the extension 58 is coaxial with the main or principal axis 36 of the lamp swivel 10, as shown. The first member body 56 is provided with a lateral threaded recess or socket 60 to receive the end 30 of the linear support means 16, as well as an upper threaded recess or socket 62 to receive the plug 54; the recess or socket 62 being coaxial with the axis 55 and the principal axis 36. A cylindrical pin 64 constituting a pin means extends laterally outwards from the outer surface of the extension 58; in this case, pin 64 is mounted in and extends outwards from a circular pocket or recess 66 in the outer surface of the extension 58. The pin 64 is detachably insertable into the pocket 66, and the typically cylindrical pin 64 is usually coaxially inserted into the generally circular pocket 66. With regard now to the lower member 14, this member 14 is characterized by having a central axis 68 which is aligned along the central axis 36, so that the main or principal axis 36 of the lamp swivel 10 is coaxial with both axes 55 and 68, and so that the cylindrical body 70 of the second or lower member 14 is disposed along the second central axis 68. One end 72 of the lower member body 70, in this case the upper end as shown, is provided with a cylindrical recess 74. This body recess 74 is coaxial with the axes 68 and 36 and, as shown, the recess 74 has a diameter slightly greater than the diameter of the extension 58, so that the extension 58 is contiguously insertable into the recess 74, as best seen in FIG. 5. As best shown in FIG. 2, the lateral inner surface of the recess 74 is provided with a slot 76 and a circular groove 78. The inner surface slot 76 extends from the one end 72 of the body 70 of the lower second member 14, to the circular groove 78 in the surface of the recess 74. The groove 78 is coaxial with the axes 68 and 36. Thus, as best seen in FIG. 5, when the extension 58 is inserted, either by manipulation or mechanically, into the recess 74, at least a portion of the first central axis 55 is coaxial with the second central axis 68. The pin means 64 is then concomitantly receivable through the slot 76 and into the groove 78, so that the first or upper member 12 is detachably attached to the second or lower member 14, as shown in FIG. 5. This FIG. 5 shows how the pin means 64 is receivable in, and rides in the groove 78, when the first member 12 is at least partially rotated about the main or principal axis 35, which in FIG. 5 concurs with the first central axis 55, while the second member 14 either remains stationary or concomitantly rotates about the second central axis 68, which lies along and concurs with the principal axis 36. The body 70 of the second or lower member 14 is detachably attached via lateral threaded recess or socket 80 to the end 50 of the lamp post or rod 40 which extends to the lamp base 38. In addition, a bottom plug 82 is screwed into a lower threaded recess or socket 84 in the bottom of the body 70. FIG. 5 also shows, in this preferred embodiment of the invention, that when the first upper member 12 and the second lower member 14 are of generally equal outer diameter, then these cylindrical bodies 56 and 70 serve to form an entire assembled lamp swivel 10 in which the outer surface devines a single cylindrical body, see especially FIG. 1. Referring now to FIG. 6, the fully assembled and functional lamp swivel is shown. The outer surface portion 86 of the second member body 70 has been coined, i.e. stamped inwards, at and/or adjacent to the junction of the slot 76 and the groove 78. This naturally should only occur in practice after the pin means 64 has been inserted through the slot 76 and into the groove 78, followed by the rotation by manual manipulation or mechanically of the first member 12 relative to the second member 14, so as to displace the pin 64 away from the slot 76. This outer surface portion 86 must of course be coinably stampable inwards, e.g. the body member 70 will be composed (at 86) of a coinable metal, such as brass, bronze, copper, aluminum, wrought iron, or the like. Thus, the pin 64, as seen in FIG. 6, cannot be again channeled through the slot 76, and is permanently disposed in the groove 78. Consequently, as shown in FIG. 6, the first and second members 12 and 14 are permanently attached to each other, and rotatable relative to each other by less than 360 degrees. The present lamp swivel is amenable to a rectilinear orientation of the swivel 10 and the lamp posts or rods 16 and 40, in which case ends 30 and 50 will extend and be screwed into the respective recesses 62 and 84, or vice versa. It is also feasible to extend one of the posts 16 or 40 laterally into the lamp swivel 10, while the other post extends coaxially or longitudinally into the lamp swivel 10. It thus will be seen that there is provided a lamp swivel which achieves the various objects of the invention and which is well adapted to meet the conditions of practical use. As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. Thus, it will be understood by those skilled in the art that although preferred and alternative embodiments have been shown and described in accordance with the Patent Statutes, the invention is not limited thereto or thereby, since the embodiments of the invention particularly disclosed and described herein above is presented merely as an example of the invention. Other embodiments, forms and modifications of the invention coming within the proper scope and spirint of the appended claims, will of course, readily suggest themselves to those skilled in the art.

A lamp swivel composed of two main coaxial members, which are at least partially rotatable relative to each other. An inner pin extends from one member to a circular inner groove in the other member, the groove being coaxial with the members. However, the other member, usually composed of a metal such as brass, copper or aluminum which may be anodized, is coined so as to prevent egress of the pin from the groove. Thus the two members are semi-permanently attached to each other and can rotate, by less than 360 degrees, relative to each other. The invention is especially applicable to provide an articulated lamp mounting for a swing arm lamp or the like, the lamp swivel being a swivel connector or coupling means which provides an articulated mounting attachment for the lamp.

CROSS-REFERENCE TO RELATED APPLICATION This application is a divisional application of U.S. patent application Ser. No. 10/686,325, filed Oct. 14, 2003 now U.S. Pat. No. 7,621,102, which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The present invention relates generally to door constructions and more particularly, to replaceable door edge arrangements. BACKGROUND OF THE INVENTION One popular form of vertically hung doors typically comprises a wooden frame defining outer dimensions of the door, panels of sheet material, such as plywood, plastic or metal covering the frame or both sides, and a core within the frame, which may be solid or hollow. In certain high traffic environments, for example, schools, hospitals and other types of health care institutions, doors are often subjected to impacts from carts, wagons, dollies, etc. which take their toll on the doors, particularly along their free edges and the hinged edges. Nicks, gouges and cracks produced along door edges by such impacts compromise a door's ability to effect a secure closure, which is particularly important where the door serves as a fire barrier as well as a closure, and mar its aesthetic appearance. Heretofore, when a door edge was severely damaged, it was necessary either to replace the door in its entirety or to refinish it. With the latter expedient, the door panels may also have to be replaced and, in any event, the door will have to be refinished as well. The cost of maintaining the structural integrity and appearance of the many doors in a hospital, for example, can become substantial. SUMMARY OF THE INVENTION The object of the present invention is to minimize the necessity of replacing or refinishing doors that have been severely damaged along their edges by enabling a damaged door edge to be simply and inexpensively restored. The foregoing object is achieved by constructing a door with a replaceable edge strip or stile which, when damaged, can be readily removed and replaced with a new one, thereby restoring the door's integrity and appearance. In accordance with the invention, this is achieved by so constructing the door such that the replaceable edge strip or the replaceable stile can be removed and replaced without affecting the door frame or door slab, thus eliminating the need for otherwise replacing or refinishing the door. The stile is so configured that it can be covered with a plastic cap that provides an extra layer of protection against damage and helps maintain a snug seal against a doorway or an opposite door. Another feature of the invention is the incorporation in the replaceable door edge assembly of an intumescent (heat expanding) material such that in case of fire, the edge is expanded outwardly to effect a tighter seal with the surrounding doorway or opposite door. The fire safety rating of the door is thus improved. Still another feature of the invention is the incorporation in the door edge construction of an accent material to provide a reveal, or line of color different than the door panel color, for aesthetic and/or identification purposes. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other features and advantages of the invention will become apparent from the following detailed description thereof, taken in conjunction with the appended drawing, in which: FIG. 1 is an oblique view partially cut away, of a door incorporating the present invention; FIG. 2 is a cross-section of the door of FIG. 1 , taken along the line 2 - 2 ; FIG. 3 is an enlarged view of the right-hand portion of the cross-section view of FIG. 2 showing the door edge construction of the invention in greater detail; FIGS. 4A , 4 B and 4 C illustrate modifications of the door edge construction of FIG. 3 ; FIG. 5 is an enlarged cross-sectional view similar to FIG. 3 illustrating the incorporation of an intumescent strip in the door edge construction of the invention; FIG. 6 illustrates a modification of the door edge construction of FIG. 5 ; FIGS. 7A , 7 B, 7 C and 7 D illustrate the replaceable door edge construction of the invention incorporating various types of accent strips or reveals FIGS. 8A and 8B illustrate variations of the invention embodying an alternate tongue and groove arrangement for securing the replaceable stile to the door edge; FIG. 9 illustrates a variation of the invention in which the tongue and groove members are covered with metal channels; FIG. 10 illustrates a modification of the arrangement of FIG. 9 ; FIGS. 11 and 12 illustrates variations of the arrangement of FIG. 9 ; and FIG. 13 illustrates a replaceable stile arrangement in accordance with the invention in which the width of the replaceable stile is adjustable. DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings, in particular FIGS. 1 , 2 and 3 , a door of the type commonly used in health care facilities and the like, but incorporating the present invention, is shown. Such a door 20 typically comprises vertical stiles 22 and top and bottom rails 24 , surrounding a core 26 . The stiles 22 and rails 24 preferably are made of hardwood and the core 26 of particle board, although other materials may be used to provide the necessary strength and rigidity. Finish panels 28 cover the particle board core, top and bottom rails and stiles on both sides to provide strength, impact resistance and aesthetic appeal. As seen best in FIG. 3 , the panels 28 may comprise a hardboard layer 28 a covered by a decorative plastic cladding 28 b such as of ACROVYN®, a vinyl acrylic plastic manufactured by Construction Specialties, Inc., Lebanon, N.J. The layers 26 , 28 a and b are laminated together to form a 5-ply construction. Doors of the type illustrated are manufactured, for example, by Jeld-Wen, Inc. Doors 20 may be made in dimensions to fit various size doorways in which they are mounted. As will be appreciated, the door 20 may be hinged to swing around along either vertical edge to suit the application. In a typical installation often found in health care facilities, a pair of such doors are hinged at opposite edges to close a wide hallway and are swingable in both directions so that rolling beds, carts, etc may be pushed through without the need to hold the door open. As discussed above, such doors are subjected to repeated, severe impact by beds, carts, etc., as they are pushed through the doors, often resulting in significant damage to the free vertical edges of the doors. Not only is the appearance of the door thus marred, the integrity of the closure and its fire resistance capability is degraded. Heretofore, in the case of significant edge damage, it was necessary to completely replace a damaged door with a new one to restore the closure's appearance and integrity, at substantial cost. In accordance with the present invention, the vertical edges of a door such as described herein are fabricated with separable edge assemblies that can be readily replaced if damaged, thereby avoiding the necessity of complete door replacement and greatly reducing the cost of restoring the door's appearance and integrity. A preferred embodiment of the removal door edge arrangement of the invention is shown in FIGS. 1 , 2 and 3 ; most clearly in the enlarged section through a door edge of FIG. 3 . The vertical door stile is indicated at 22 and the replaceable edge assembly indicated at 30 . The latter comprises replaceable stile 32 , preferably of hardwood, extending the full length of the edge stile 22 and a plastic cover 34 secured over replaceable stile 32 . Stile 22 is milled with a longitudinal tapered grove 22 a and replaceable stile 32 with a longitudinally extending complementary tapered spline 32 a , forming a snug tongue-and-groove mating of stile 22 and replaceable stile 32 . A plurality, e.g., 4 , of screws 36 , spaced along the door edge, firmly but releasably secure replaceable stile 32 to stile 22 . If desired, spots of glue may also be applied between stile 22 and replaceable stile 32 to more firmly hold them together, while still allowing replaceable stile 32 to be removed when required. Cover 34 may be formed of ACROVYN® or other relatively hard but resilient material, such as aluminum or stainless steal, with inwardly directed flanges 34 a along both edges. Cover 34 is formed to be of the same shape as the outer surface of replaceable stile 32 , e.g., generally rectangular with rounded corners. Replaceable stile 32 is provided with rectangular indents 32 b along both inner longitudinal edges, such that when stile 22 and replaceable stile 32 are joined, rectangular grooves 32 b are formed therebetween extending the full length of the door. These grooves snugly receive the flanges 34 a of cover 34 . To remove a damaged cover from a door, one of the flanges 34 a is pried out of its groove and the cover bent away to release the other flange. To install a new cover, one of the flanges is inserted into its groove and the cover pressed toward the outer surface of replaceable stile 32 until the other flange snaps into the other groove. It will be understood that the curvature of the corners of the stile and cover combination discussed and illustrated may be varied to suit the particular application. For example, for paired swinging doors, such as often found across hospital passageways, the corner curvature will be of greater radius than single doors, to provide the required clearance. It will also be understood that the cover 34 need not be removable, but may be permanently secured to its replaceable stile 32 , such as by a suitable adhesive. In such an arrangement, flanges 34 a and indents 32 b may be unnecessary. FIGS. 4A , 4 B and 4 C illustrate alternative forms of the tongue-and-groove coupling of FIG. 3 , with the screws omitted for the sake of clarity. In FIG. 4A , a dovetail spline 42 mates with a corresponding grove 44 ; in FIG. 4B , the spline 46 has a partially circular cross-section to mate with a partially circular groove 4 B; and in FIG. 4C , the spline 50 and groove 52 are rectangular in cross-section. It will be understood that other variations of the tongue-and-groove cross-sections may be used as desired. FIG. 5 illustrates another embodiment which further enhances the fire resistance advantages of doors of the invention. A heat-expansion or intumescent strip 52 extends the full length of the door edge and is adhered in a groove 54 milled along the outer edge of replaceable stile 32 . Cover 34 may have a complementary groove along its inner surface to accommodate the strip as well. The strip 52 is covered by outer cover 34 when the latter is snapped in place. At normal room temperatures, strip 52 maintains its normal thickness. In case of fire or extreme heat adjacent the door, strip 52 expands, pushing cover 34 outwardly to tighten the seal between the edge of the door and an adjacent door or doorframe, thus increasing the fire resistance rating of the door. A variation of the arrangement of FIG. 5 is illustrated in FIG. 6 wherein the intumescent strip 52 is adhered in a groove 34 a formed in the outer edge of cover 34 , the inward extension of the cover 34 fitting in a groove milled along the outer edge of replaceable stile 32 . It will be understood that in the embodiments of FIGS. 5 and 6 , any of the tongue-and-groove couplings described above may be used in place of the configurations illustrated. To improve the appearance of the door, an accent strip or reveal, of a contrasting or complementary color to the remainder of the door surface, may be incorporated in the door edge arrangements of FIGS. 3 to 6 . In the embodiment of FIG. 7A , longitudinal grooves 60 are milled along opposite sides of replaceable stile 32 , inwardly of its interior face, for receiving the flanges 34 a of cover 34 , leaving exposed narrow longitudinal surfaces 62 on opposite sides of the stile, between cover 34 and the panels 28 . These exposed surfaces 62 may be painted in any aesthetically pleasing color. The reveal or accent strip may also be provided by insertion of a suitably colored strip of accent material in a slot provided between the stile 22 and replaceable stile 32 , as shown in FIG. 7B . As seen, stepped indents 64 are provided along each inner corner of replaceable stile 32 to receive the flanges of cover 34 and accent strips 66 . The strips 66 may be of PVC plastic, aluminum, stainless steel or other material having their outer surfaces ridged and slightly thicker than the grooves created upon joinder of replaceable stile 32 to stile 22 . The strips 66 are pressed into the grooves after cover 34 is inserted and the ridged surfaces resist any tendency of the strips to move out of the grooves. A variation of the accent strip of FIG. 7B is illustrated in FIG. 7C . In this modification, the inside longitudinal edges of replaceable stile 32 are milled to provide both stepped indents and longitudinal grooves for receiving L-shaped accent strips 68 . One leg of each accent strip extends outwardly to just below the respective outer surface of the door with its edge exposed when replaceable stile 32 is joined to stile 22 with the accent strip in place. In the embodiment of FIG. 7D , the accent strips comprise opposite exposed edges 70 of a strip 72 sandwiched between stile 22 and replaceable stile 32 . The accent strips of FIGS. 7B-D may be made of any suitable material, including PVC plastic, aluminum and stainless steel. FIGS. 8A and 8B illustrate variations of the tongue and groove arrangements of the invention shown in the previous embodiments. In both variations, the groove in the stile 22 is rectangular (as in FIG. 4C ) and lined with a U-shaped channel 80 having longitudinal ridges 82 formed along both interior sides of the channel. Channel 80 is secured in the rectangular groove milled in stile 22 by screw 84 . Adhered along the inner surface of replaceable stile 32 is a tongue plate 86 having integral longitudinal extending flanges 88 with longitudinally extending ridges 90 formed along their outer surfaces. The pair of flanges 88 and channel 80 are dimensioned such that the flanges are snugly received within the channel and the respective ridges 82 , 90 engaged to secure replaceable stile 32 to stile 22 . Tongue plate 86 may extend the full width of stile 32 , with rounded edges extending slightly beyond the door panel as in FIG. 8A , or be narrower than the width of the stile and received in a depression milled in the inner surface of replaceable stile 32 , as in FIG. 8B . In the embodiment of FIG. 8A , the rounded extensions of the tongue plate 86 may serve as accent strips. In FIG. 8B , accent strips are provided by inserts 92 between the edges of cover 34 and stile 22 . In both embodiments, intumescent strips 52 may be provided. Channel 80 and tongue plate 86 may be made of aluminum or other metal or plastic, as desired. In the embodiment of FIG. 9 , a dovetail tongue and groove coupling between stile 22 and replaceable stile 32 , such as shown in FIG. 4A , has both tongue 94 and groove 96 covered with channels of this aluminum, steel, or other material providing low friction slideable surfaces, 98 a and 98 b , respectively, which extended to the outer surfaces of the door. The covered channels facilitate the insertion and removal of replaceable stile 32 on stile 22 . A variation of the embodiment of FIG. 9 is shown in FIG. 10 , in which the extents of the metal channels 100 a and 100 b are limited to the extents of the groove and tongue, respectively. The space left between stile 22 and replaceable stile 32 is filled with tapered inserts 102 , which serve to wedge the members 22 , 32 apart and also to provide accent strips. In FIG. 10 , a single metal channel 110 is applied to the dovetail tongue element only and in FIG. 11 , the single metal channel 112 is extended outwardly between stile 22 and replaceable stile 32 to the door faces with rounded outer edges 114 which provide accent strips. To accommodate different door thicknesses, the adjustable width replaceable stile of FIG. 13 is advantageous. In this embodiment, the replaceable stile is made up of two separate longitudinal elements 132 a and 132 b , each having a generally L-shaped cross-section overlying and nesting with each other to be slideable away from each other between a minimum width arrangement wherein the respective longitudinal edges of elements 132 a and 132 b are in contact with each other and a maximum width configuration wherein the respective longitudinal edges are separated. Opening 134 is of greater diameter than screw 36 to allow for varying amounts of separation. It will be seen from the foregoing that the present invention provides a simple, inexpensive way of repairing damaged doors by allowing replacement only of a removable door edge assembly, thereby saving the considerable exposure of replacing an entire door. Although a number of specific embodiments of the invention above have been illustrated, various modifications thereof will be apparent to those skilled in the art within the spirit of the invention. For example, replaceable stile 32 and cover 34 may be made as a single integral member and joined to stile 22 as shown. Also, the tongue-and-groove coupling between replaceable stile 32 and stile 22 may be eliminated, if desired and any of these variations may be provided with or without intumescent strips. Accordingly, it will be evident that the scope of the invention is to be limited only as set forth in the appended claims.

A door is constructed with a separate member joined to the door edge by a tongue-and-groove coupling and screws so as to be readily removable and replaceable. The separate member sustains the impacts imparted to the door by carts or wagons pushed past the door and can be readily replaced when damaged, thus avoiding replacement of the entire door. A flexible cover snaps over the outer surface of the separate member to add impact resistance and aesthetic appeal. Intumescent strips may be inserted inside or outside of the cover to enhance sealing between the door, and as adjacent door or door frame, thereby improving the fire resistance rating of the door. Accent strips or reveals of contrasting or complementary colors may be incorporated to add to the aesthetic appeal of the door. The door construction is of particular utility in schools, health care facilities and other institutions.

FIELD OF THE INVENTION This invention relates to concrete masonry unit wall construction and, more particularly, to a drainage system therefor. BACKGROUND OF THE INVENTION Single wythe masonry walls are constructed using concrete masonry units (CMUs). CMUs are sometimes referred to as cinder blocks. A CMU consists of a hollow rectangular building block typically having a central web providing two vertical cores or cavities. In singly wythe masonry wall construction a foundation is formed, typically of concrete. The wall is formed by laying the CMUs in alternating fashion in multiple courses depending on the height of the wall. Owing to the construction, the vertical cores of CMUs are aligned to provide a continuous channel from the top of the wall down to the foundation. Mortar is used in joints to join the CMUs. Cracks in the CMUs can allow water to enter the cores. Moisture can also condense in the cores under changing temperatures. Either way, water may collect in the cores in the CMUs. The presence of moisture in the cores is undesirable for a number of reasons. First, the trapped moisture can degrade the structure. Second, the presence of water under freezing temperatures may also cause cracks in the wall when water expands as it freezes. Trapped water in the cores in the CMUs may cause the CMUs to become discolored, and may even migrate into the dwelling. To overcome the problems associated with water trapped within the CMU cores, weep holes are commonly included along the base of the outer side of the CMUs in the lowermost course. The weep holes allow water to pass from the core to drain outside the wall structure. A flashing disposed in the core directs the collected water toward the weep holes. During construction of a single wythe masonry wall, excess mortar and other debris can and does fall into the cores. When the CMUs are stacked during the erection of the wall, for example, mortar droppings are squeezed into cores within the CMUs. The excess mortar, as well as other debris, such as insulation, drops to the base of the core, and can block weep holes. One known solution is to construct a CMU drainage course consisting of two wythes separated by a cavity sized to accommodate through wall flashing and blocks of water permeable material. This solution uses different style concrete blocks in the drainage course. Another known solution, shown in U.S. Pat. No. 6,202,366, uses a collection pan under each CMU core of a selected course to collect water in the core. A weep channel on the pan drains the water to the exterior of the wall. This solution requires a collection pan for each core. Also, each pan must be aligned prior to applying mortar so that once a subsequent course is laid each pan is properly aligned with the CMU. The present invention is directed to solving one or more of the problems discussed above, in a novel and simple manner. SUMMARY OF THE INVENTION In accordance with the invention, there is provided a drainage system for use in concrete masonry unit (CMU) wall construction. Broadly, the drainage system comprises a tray unit of a size corresponding to size of CMUs, to be received beneath a course of CMNs, in use. The tray unit comprises opposite side flanges to abut a superjacent CMU and supporting a pan therebelow. A strip of water permeable material is attached to an upper surface of the pan and extends transversely beyond a front edge of the pan. A block of water permeable material is positioned above the pan and extends upwardly into a hollow core of a CMU. The water permeable material of the strip and the block has a porosity sufficient to permit water to pass therethrough but substantially insufficient to permit mortar and debris to pass therethrough so that water in a hollow core of a CMU drains through the strip. It is a feature of the invention to provide an adhesive layer on the opposite side flanges to adhere to a CMU. The adhesive may be on an upper surface of the opposite side flanges to adhere to a superjacent CMU It is another feature of the invention that the pan is sloped downwardly toward the front edge. It is still another feature of the invention to provide front and rear flanges extending between the side flanges to support the pan. The front flange includes a notch receiving the strip. The strip extends forwardly of the front flange. It is still another feature of the invention that the water permeable material is a non-water absorbent randomly oriented fibrous material. It is still a further feature of the invention that the block is T-shaped having a top part wider than a CMU core and a bottom part narrower than a CMU core. It is still another feature of the invention that the block is taller than a CMU so that the top part bends to conform to a CMU core and the bottom part extends horizontally to cover a portion of the strip disposed in a CMU core. There is disclosed in accordance with another aspect of the invention a drainage system for use in CMU wall construction, each CMU including a pair of hollow cores. The drainage system comprises a generally rectangular tray unit of a size corresponding to size of CMUs, to be received beneath a course of CMUs, in use. The tray unit comprises a perimeter flange, a web flange connected transversely centrally within the perimeter flange, the flanges to abut a superjacent CMU, and a pair of pans each supported between the perimeter flange and web flange and each on opposite sides of the web flange. A pair of strips of water permeable material are each attached to an upper surface of one of the pans and extending transversely beyond a front of the perimeter flange. A pair of blocks of water permeable material are positioned above the pans and extending upwardly into hollow cores of a CMU, in use. There is disclosed in accordance with a further aspect of the invention a drainage system for use in CMU wall construction comprising an elongate tray element of one piece construction to be received beneath a course of CMUs, in use, comprising a plurality of aligned, generally rectangular tray units each of a size corresponding to size of cores. Each tray unit comprises a perimeter flange to abut a superjacent CMU, and a pan supported within the perimeter flange. A plurality of strips of water permeable material are each attached to an upper surface of one of the pans and extend transversely beyond a front of the perimeter flange. It is a feature of the invention that each perimeter flange comprises front and rear flanges extending between opposite side flanges to support the pans. The front flange includes a notch receiving the strip. It is still another feature of the invention that at least one side flange of each tray unit adjoins a side flange of an adjacent tray unit. It is still a further feature of the invention that adjoining side flanges are separated by a score line. Further features and advantages of the invention will be readily apparent from the specification and from the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exterior perspective view of a drainage system in accordance with the invention used in a single wythe masonry wall formed by courses of concrete masonry units (CMUs); FIG. 2 is a perspective view of a tray of the drainage system of FIG. 1 ; FIG. 3 is a sectional view taken along the line 3 — 3 of FIG. 2 ; FIG. 4 is a sectional view taken along the line 4 — 4 of FIG. 2 ; FIG. 4A is a sectional view, similar to FIG. 4 , for a tray according to an alternative embodiment of the invention; FIG. 5 is a perspective view, similar to FIG. 2 , illustrating the tray with a peel and stick adhesive layer; FIG. 6 is a side elevation exploded view illustrating the tray of FIG. 2 prior to attachment to a CMU; FIG. 7 is a side elevation view, similar to FIG. 6 , illustrating the tray attached to the CMU; FIG. 8 is an elevation view of a block of water permeable material in a static state used in the drainage system of FIG. 1 ; FIG. 9 is a perspective view of the block of FIG. 8 bent to conform to walls of a CMU hollow core; FIG. 10 is a perspective view, with a CMU removed for clarity, illustrating relationship between the block and the tray in accordance with the invention; FIG. 11 is a plan view of a tray element in accordance with an alternative embodiment of the invention comprising a plurality of trays; FIG. 12 is a perspective view of a tray in accordance with the invention to accommodate a rebar; and FIG. 13 is a perspective view of an adapter used with the trays in accordance with the invention to accommodate rebar. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1 , a drainage system 20 is illustrated in connection with concrete masonry unit (CMU) wall construction. In the illustrated embodiment of the invention, the drainage system 20 is used in a single wythe masonry wall construction 22 formed by courses 24 of CMUs 26 . The wall construction 22 is used on a building structure including a foundation wall 28 . In the illustrated embodiment of the invention, the foundation wall 28 comprises a concrete wall. The foundation wall could be of block construction, as will be apparent to those skilled in the art. Referring also to FIG. 10 , the drainage system 20 comprises a tray 30 and a pair of blocks 32 of water permeable material. CMUs 26 most typically have a nominal height of eight inches, a nominal length of sixteen inches and come in nominal widths of eight, ten or twelve inches. Actual sizes are about ⅜ inches less to allow for a ⅜ inch mortar joint. The CMU 26 comprises a hollow concrete block 34 having a web 35 to provide a pair of vertically extending hollow cores or cavities 36 therethrough. The hollow cores or cavities 36 are typically about five inches square. In conventional single wythe masonry wall construction, a first course 24 - 1 of CMUs 26 is secured to the foundation wall 28 with a layer of mortar. Mortar is also provided between adjacent CMUs 26 . A layer of mortar is then placed upon the first course 24 - 1 and the second course 24 - 2 is laid on the first course 24 - 1 . Again, mortar is provided between each CMU 26 . The CMUs 26 in each course are typically offset from one another as illustrated in FIG. 1 . As a result, the vertical cores 36 in any course 24 are aligned with the vertical cores 36 in other courses 24 to provide a continuous channel from the top of the wall down to the foundation wall 28 , as is well known. Referring to FIGS. 2-4 , the tray 30 comprises a tray unit 38 and a pair of strips 40 of water permeable material. The tray unit 38 is of one piece molded plastic construction and has a length and a width less than that of a CMU so that it can be set in mortar and the mortar will set up and secure the tray unit 38 in position. For example, the length of the tray unit 38 may be on the order of twelve inches and the width of the tray unit 38 may be on the order of six inches for an eight inch wide CMU. The tray unit 38 comprises a peripheral flange 42 formed by a front flange 44 , a rear flange 46 , a right side flange 48 and an opposite left side flange 50 . A web flange 52 is connected transversely, centrally within the perimeter flange 42 and in particular extends from a center of the rear flange 46 to a center of the front flange 44 . The perimeter flange 42 and the web flange 52 are U-shaped in cross section, as shown in FIGS. 3 and 4 , and open downwardly. A pair of pans 56 and 58 are supported between the perimeter flange 42 and the web flange 52 each on opposite sides of the web flange 52 . Particularly, the first pan 56 is supported in an area bound by the left side flange 50 , the front flange 44 , the web flange 52 and the rear flange 46 . Similarly, the right pan 48 is supported in an area bound by the web flange 52 , the front flange 44 , the right side flange 48 , and the rear flange 46 . The pans 56 and 58 are generally rectangular in shape and of a size at least as large a shape of the hollow cores 36 . The perimeter flange 42 and web flange 52 define an upper surface 60 . In the embodiment of FIGS. 2-4 , the upper surface 60 is planar and the pans 56 and 58 are likewise planar and parallel to the upper surface 60 . FIG. 4A illustrates a tray unit 38 ′ in accordance with an alternative embodiment of the invention. This embodiment differs in that the pans, including a left pan 56 ′, are sloped from the rear flange 46 toward the front flange 44 . Indeed, depending on the slope, the rear flange 46 may even be eliminated. The sloped pans enhance drainage toward a front edge 62 of the pan 56 ′ and thus the front flange 44 to enhance drainage. The pan 56 ′ could also be sloped from the sides toward the strip 40 . In the illustrated embodiment of the invention, the tray unit 38 has a uniform wall thickness on the order of {fraction (1/16)} inch. Alternatively, the flanges could be solid plastic. The front flange 44 includes a pair of notches 64 and 66 . The notch 64 is associated with the left pan 56 and is centered between the left side flange 50 and the web flange 52 . Similarly, the right notch 66 is associated with the right pan 58 and is centered between the web flange 52 and the right side flange 48 . The strips 40 are of a water permeable material having a thickness in the range of about ⅛ inch to ½ inch with ¼ inch being typical. The strips 40 are adhered in any known manner to the pans 56 and 58 and extend transversely beyond the front edge 62 of the pans 56 and 58 and also beyond front flange 44 . The strips 40 function to permit water to pass therethrough and to substantially prevent mortar and other debris from passing therethrough. The material is preferably a non-absorbent water-permeable, fibrous mesh material formed with circuitous (non-linear) pathways. The material is preferably a mass of random filament-type plastic fibers. The strip may also include an outer layer of backing material. The backing material may be a finely woven paper like material which will pass water but not fine debris, such as vermiculite or the like. Overall, the material is sufficient to catch and support mortar and debris without significant collapse, but allow water to pass freely therethrough. The strips 40 may be secured with a suitable adhesive or molded in situ with the tray unit 38 . Referring to FIG. 5 , the tray unit 38 includes an adhesive layer 68 on the upper surface 60 . The adhesive layer 68 is initially covered by a removable film 70 to provide a peel and stick configuration. In the illustrated embodiment of the invention, the adhesive layer 68 covers the entire upper surface 60 . Alternatively, the adhesive layer could be provided only on the side flanges 48 and 50 and the web flange 52 , as necessary or desired. Likewise, the adhesive layer could be provided on a bottom surface, particularly when used with solid flanges. To install the tray 30 , it is positioned below a CMU 26 , as illustrated in FIG. 6 , after removal of the protective sheet 70 . Thereafter, it is pressed against the bottom of the CMU 26 so that the adhesive layer 68 , see FIG. 5 , causes the tray unit 38 to adhere directly to the CMU 26 . This allows the tray 30 to be properly aligned with the CMU 26 so that the pans 56 and 58 are positioned directly below the cores 36 . As is apparent, the tray 30 could be turned upside down and secured to an upside down CMU which is then turned over to be laid on the foundation wall 28 . More particularly, a layer of mortar is applied to the top of the foundation wall 28 in a conventional manner and the CMU 26 with the tray 30 installed thereon is laid in the mortar for to set up in a conventional manner. Thereafter, the strips 40 extend outwardly of the CMUs 26 , as generally illustrated in FIG. 1 . As illustrated, the strips 40 are of a length to extend forwardly of the CMU 26 and then optionally be cut off after the mortar sets or be provided with a score line to be broken off. Referring to FIG. 8 , the block 32 comprises a T-shaped sheet 72 of water permeable material, similar to material of the strips 40 . The sheet 72 has a thickness in the range of about ⅛ inch to ½ inch with ¼ inch being typical. The sheet 72 has a top part 74 wider than a CMU core 36 and a bottom part 76 narrower than a CMU core 36 . For example, with a CMU having a 5×5 inch core, the top part 74 might be about six to eight inches across and about seven inches tall, while the bottom part 76 might be on the order of four inches across and four inches tall. The block 32 is then stuffed in a core 36 of the first course 24 - 1 by bending the bottom part 76 so that it extends horizontally and thus perpendicular to the top part 74 and then curving opposite ends 78 and 80 of the top part 74 to conform to the walls of the core 36 . As a result, the curve of the top part 74 gives stability to the mesh material to withstand impact of falling mortar. The proper type of mesh, as described above, will provide a prickly adhesion to the porous walls of the CMUs 26 . The horizontal bottom part 76 covers the drainage strip 40 to protect it from being plugged by mortar droppings or granular or foam insulation. FIG. 10 illustrates a tray unit 30 with one block 32 installed over the left pan 56 . For clarity, the CMU 26 is not shown in FIG. 10 . As is apparent, the block top portion 74 will be supported above or by the tray unit upper surface 60 . The bottom portion 76 could be resting directly atop the strip 40 or be supported slightly above the strip 40 , as necessary or desired. As described, the tray 30 is adapted to function with a dual core CMU, such as a CMU 26 . The tray unit 38 could be provided with a single pan with two strips 40 as by eliminating the web flange 52 for use with dual cores, or could be provided in half the size with only a single pan for use with a smaller CMU having only a single core. Referring to FIG. 11 , a tray element 90 according to an alternative embodiment of the invention is illustrated. The tray unit 90 comprises a plurality of trays 30 formed together of one piece construction to be received beneath a plurality of CMUs 26 in a course. In the illustrated embodiment of the invention, the tray element 90 comprises six trays 30 integrally joined together so that at least one side flange of each tray 30 adjoins a side flange of an adjacent tray. A score line 92 could be provided between adjacent trays 30 for separability in the field if fewer than six trays 30 are required. Also, a score line 92 could be provided between pans 56 and 58 of each tray 30 in the event that an odd number of cores are present. In all other respects, the trays 30 are as described above relative to FIGS. 2-5 . As is apparent, the tray element 90 could have more or less than six trays 30 . After installation, a block 32 of water permeable material will be positioned above the tray element 90 at each core 36 , as described above. Referring to FIG. 12 , a tray 100 is adapted to accommodate rebar in a reinforced wall. The tray unit 100 comprises a pan 102 connected to a left side sloped end wall 104 . The end wall 104 includes a semicircular notch 106 to receive a rebar. The notch 106 should be sized larger than the rebar to allow field placement of the tray 100 . Front and rear flanges 108 and 110 , respectively, extend across the pan 102 and the end wall 104 and are connected by a right side flange 112 . A notch 114 in the front flange 114 receives a strip 40 of water permeable material, as above. As is apparent, the end wall 104 and side flange 112 could be reversed for installation on the opposite side of the rebar. FIG. 13 illustrates an adapter 120 for use with the tray 30 of FIG. 2 to accommodate rebar. The adapter 120 comprises a plate 122 having a notch 124 on one side edge 126 and a downwardly depending lip 128 on an opposite edge 130 . The lip 128 can hook over a side flange 48 or 50 so that the notched edge 126 is away form the pan 58 or 56 . Though the block 32 is described as a T-shaped sheet element, other configurations for the block 32 could also be used. These blocks include triangular elements, cylindrical elements, as well as other shapes. Such shapes and the water permeable material are described in applicant's pending application Ser. No. 10/393,689, filed Mar. 21, 2003, the specification of which is hereby incorporated by reference herein. Thus, in accordance with the invention, there is provided a drainage system including a tray unit including a pan with a strip of water permeable material attached to an upper surface of the pan and a block of water permeable material position above the pan. In one embodiment, a peel and strip adhesive is applied to the tray unit so that it is self adhering to a CMU prior to laying of the CMU on a foundation wall.

A drainage system for use in concrete masonry unit (CMU) wall construction comprises a tray unit of a size corresponding to size of CMUs, to be received beneath a course of CMUs, in use. The tray unit comprises opposite side flanges to abut a superjacent CMU and supporting a pan therebelow. A strip of water permeable material is attached to an upper surface of the pan and extends transversely beyond a front edge of the pan. A block of water permeable material is positioned above the pan and extends upwardly into a hollow core of a CMU. The water permeable material of the strip and the block has a porosity sufficient to permit water to pass there through but substantially insufficient to permit mortar and debris to pass there through so that water in a hollow core of a CMU drains through the strip.

CROSS REFERENCE TO RELATED APPLICATIONS Under 35 USC §119(e)(1), this application claims the benefit of prior U.S. provisional application Ser. No. 60/085,615, filed May 15, 1998. FIELD OF THE INVENTION This invention is in the general field of diagnosing feline immunodeficiency virus (“FIV”) infection. BACKGROUND OF THE INVENTION Infection with a variety of lentiviruses is associated with immunodeficiency disease. Cats infected with FIV (Pedersen et al., Science 235:790-793, 1987; U.S. Pat. No. 5,037,753), for example, show a number of pathogenic symptoms reminiscent of acquired immunodeficiency disease (“AIDS”) (Yamamoto et al., Am. J. Vet. Res. 49:1246-1258, 1988; Ackley et al., J. Virol. 64:5652-5655, 1990; Siebelink et al., AIDS Res. Hum. Retroviruses 6:1373-1378, 1990). FIV-associated feline AIDS is an important feline disease, with incidences as high as 15% in populations of sick animals (O'Connor et al., J. Clin. Microbiol. 27:474-479, 1989). The transient, low level viremia often seen in connection with the persistence of intracellular proviruses makes detection of the antibody response to infection a reliable assay for infection by FIV. Enzyme-linked immunosorbent assays (“ELISA”) for detecting FIV antibodies use purified, inactivated FIV virions and/or antigens as solid-phase reagents to bind FIV antibodies in samples. Antibodies recognizing epitopes on the gag-encoded p24 capsid (“p24”) and p15 nucleocapsid proteins and on the env-encoded gp40 transmembrane (“gp40”) and gp100 surface proteins have been detected by radioimmunoprecipitation analysis (“RIPA”) or immunoblot (Hosie et al., AIDS 4:215-220, 1990; Steinman et al., J. Gen. Virol. 71:701-706, 1990; Andersen et al., U.S. Pat. No. 5,656,732; Kemp et al., U.S. Pat. No. 5,591,572; Mermer et al., Similarities between the Transmembrane Proteins of FIV and HIV, Cold Spring Harbor Symposium, RNA Tumor Viruses, 1991; Tilton et al., J. Clin. Microbiol. 28:898-904, 1990). Various anti-FIV antibodies have also been generated (O'Connor et al., U.S. Pat. Nos. 5,219,725 and 5,177,014). IDEXX Laboratories, Inc. markets a FIV diagnostic device under the trademark SNAP® COMBO, which detects FIV antibodies in feline samples. The device includes recombinant p24 as a solid-phase capture reagent. FIV antibody captured by the solid-phase reagent is detected with disrupted FIV conjugated to horseradish peroxidase. See U.S. Pat. Nos. 5,726,010 and 5,726,013. SUMMARY OF THE INVENTION Applicants have discovered that detection of FIV antibodies indicative of FIV infection is improved by using a polypeptide marker composition that is enhanced for the presence of both FIV env polypeptides and FIV gag polypeptides. By “enhanced” is meant that the FIV env and gag polypeptides are present in the marker composition at higher weight percentage levels than in a simple mixture of FIV proteins obtained from disrupted virus. Enhancement can be achieved, e.g., by spiking the viral mixture with a purified or partially purified preparation of the env and gag polypeptides, or by using such a preparation as a marker composition without inclusion of the viral mixture. Accordingly, the invention features a diagnostic method for determining FIV infection by contacting a feline sample (e.g., a serum or blood sample) with an antibody-binding capture composition that includes both enhanced FIV env and gag polypeptides. An enhanced (e.g., purified) polypeptide can be a recombinant or synthetic polypeptide, or a polypeptide isolated from FIV virions. The reaction of antibodies in the sample with the capture composition indicates that the donor of the sample is infected with FIV. An immunogenic fragment of a polypeptide is a polypeptide fragment that can bind to one or more antibodies that are specific to the polypeptide in its native conformation. Immunogenic fragments of a FIV gag precursor p55 include, but are not limited to, p55 itself, p55 cleavage products such as p24, p15, and p10, and any p55 fragments recognized by monoclonal antibody (“mAb”) 2D4 (American Type Culture Collection (“ATCC”) HB9890), 3H8 (ATCC HB12531), 4F2 (ATCC HB9888), 2H4 (ATCC HB12530), or 6E6 (ATCC HB9899). Immunogenic fragments of a FIV env precursor gp130 include, but are not limited to, gp130 itself, gp130 cleavage products such as gp40 and gp110; they also include any gp130 fragments containing a cysteine loop of gp40 and any gp130 fragments that bind to mAb 2F11 (ATCC HB10295), 1C9 (ATCC HB12529), or 3H9 (ATCC HB12528). An exemplary immunogenic fragment of gp130 is ELGCNQNQFFCK (SEQ ID NO:1). An exemplary second capture polypeptide is CELGCNQNQFFCK (SEQ ID NO:2). In one embodiment of the above-described method, the binding composition is attached to a phase (e.g., a solid phase) immiscible with the sample. An antibody-binding detection composition can be applied to detect reaction of antibodies in the feline sample with the capture composition. This detection composition may include two detection polypeptides that respectively contain immunogenic fragments of p55 and gp130. For instance, the detection composition can contain disrupted FIV (e.g., a mixture of viral proteins obtained by disrupting native FIV virions with a detergent) spiked with a peptide having the sequence of SEQ ID NO:1or 2. The polypeptides in the detection composition are preferably labeled with a detectable moiety, such as an enzyme that catalyzes a detectable reaction, colloidal gold, a radionuclide, and a fluorophore. Also embraced by the invention is a device for performing an assay that determines whether a feline is infected with FIV. This device contains the above-described antibody-binding capture and detection compositions. In one embodiment, the detection composition is held in a container. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Exemplary methods and materials are described below, although methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention. All publications and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. The materials, methods, and examples are illustrative only and not intended to be limiting. Other features and advantages of the invention will be apparent from the following detailed description, and from the claims. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagram representing the components of a FIV assay of the invention. FIG. 2 is an exploded view of a single-use assay device for detecting FIV. FIG. 3 is cross-section of the device of FIG. 2, assembled, before use. FIG. 4 is a cross-section of the device of FIG. 2 after use. DETAILED DESCRIPTION The invention features immunoassays for detecting FIV antibodies in a sample. FIG. 1 shows the basic components of one such assay. Antibody is captured by capture reagents (i.e., an antibody-binding composition) 10 a and 10 b which are immobilized on a solid substrate 12 by any of a large number of known methods. Specifically, the capture reagents are a mixture of FIV polypeptides which may include (a) recombinant p24 as described in greater detail below; and (b) a synthetic env (e.g. gp40) immunodominant peptide (“IDP”), also described below. The capture reagents bind to FIV antibodies 11 a and 11 b in the sample, and unbound material is washed off or removed by other known means. The presence of captured FIV antibody is detected by the use of a labeled detection reagent 14 that specifically binds to the captured antibody. The reagent is a mixture of native, recombinant, and/or synthetic polypeptides that specifically bind the target antibody. These polypeptides (e.g., 18 a and 18 b ) are each conjugated to an enzyme 16 that catalyzes a detection reaction. Since antibodies are bivalent, the captured FIV antibodies can be detected using the same epitopes as were used in the capture reagents. One specific detection reagent includes disrupted native FIV spiked with a synthetic gp40 IDP that can be the same one as described above. Any of a large number of known immunoassay formats may be used to detect the presence of anti-FIV antibodies in a sample using the above reagents. One such format is the reverse flow format used in the SNAP® device of IDEXX Laboratories, Inc. and generally disclosed in U.S. Pat. Nos. 5,726,010 and 5,726,013, which are hereby incorporated by reference. FIGS. 2-4 depict an exemplary single use device for performing a FIV assay. In FIG. 2, the device includes a bibulous flow matrix 22 held between a base 23 and a cover 24 . An activator 25 a and body 25 b surround the flow matrix 22 . Two reagent wells (an enzyme substrate well 27 and a wash well 28 are positioned in the base and covered by a well seal 29 . The activator 25 a includes two downwardly facing lances 30 which have absorbent wicks 32 at their core. An absorbent pad 34 is positioned in a recess 35 in the base. In FIG. 3, before use, cover 24 and activator 25 a are angled upward from hinge 36 . Wells 27 and 28 are filled and covered. Sample is introduced into the sample cup 38 , and sample flows from right to left (in FIG. 3) along matrix 22 . Detection reagent designed to bind to and permit detection of FIV antibodies in the sample may be mixed with the sample before it is applied to the flow matrix, or it may be pre-applied to the matrix (e.g. at 42 ), to be picked up by FIV antibodies as sample moves along the matrix. An analyte capture zone 40 includes the capture reagents described elsewhere in this application. The capture reagents are immobilized to the capture zone 40 according to standard techniques, e.g., as described in U.S. Pat. Nos. 5,726,010 and 5,726,013. FIV antibodies that react with the capture reagents bind to the capture reagents and are thereby kept in zone 40 . After a time set to permit the sample to move through zone 40 , the activator 25 a is closed by pivoting it around hinge 36 . Lances 30 pierce well seal 29 , permitting the solution of enzyme substrate in well 27 and the wash solution in well 28 to move up through wicks 32 and onto matrix 22 . At the same time, absorbent pad 34 is brought into contact with matrix 22 just upstream (to the right in the figure) of sample cup 38 , causing flow in the matrix to reverse (moving from left to right). This flow washes unbound material from zone 40 , and brings enzyme substrate into contact with the conjugated enzyme of the capture reagents, causing a detectable (e.g. color-generating) reaction at zone 40 indicative of the presence of FIV antibody in the sample. Other ELISA formats (e.g., microplate ELISA) can also be used. The results from ELISA experiments can be confirmed by Western blot analysis. Capture reagents are attached to a phase immiscible with the test sample. For instance, the capture reagents are immobilized onto a solid phase. The solid phase can be in any form (e.g., a particle, a microplate well, or a strip), and can have, e.g., a unitary (planary or curved) surface or a porous structure. Materials useful as a solid support include, but are not limited to, glass, gels, paper, cellulose, nylon, polystyrene, and latex. The capture reagents can also be covalently linked to a water-immiscible solvent that can form an emulsion with the test sample to allow the contact between the capture reagents and the target antibodies. Polypeptides serving as capture reagents can be attached to the solid surface by any of a number of standard methods, including direct adsorption or chemical coupling to reactive groups on the surface. For example, a solid surface can be derivatized to generate active amine groups; then an amine- and sulfhydryl-reactive heterobifunctional crosslinker (e.g., succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (“SMCC”) or other DOUBLE-AGENT™ crosslinkers available from Pierce, Rockford, Ill., or equivalent reagents from other vendors) is used to link a free cysteine group in the polypeptide to the amine group on the solid surface. Alternatively, homobifunctional crosslinkers also available from Pierce or other vendors can be used. The capture polypeptides can contain an immunogenic fragment of p55 or gp130. To identify such immunogenic fragments, one can digest p55 or gp130 (or their natural cleavage products, e.g., p24 or gp40) with a peptidase or CNBR, and purify the immunogenic cleaved peptides by their ability to bind to an affinity column containing an anti-p55 or anti-gp130 antibody. Anti-p55 and anti-gp130 antibodies can be generated by well known methods. See, e.g., U.S. Pat. Nos. 5,177,014 and 5,219,725; Lombardi et al., AIDS Res Hum Retroviruses 9:141-146, 1993; and Lombardi et al., J Gen Virol 76(Pt 8):1893-1899, 1995. Useful immunogenic fragments of gp130 include any of the four gp40 peptides shown at column 3 of U.S. Pat. No. 5,591,572. It can also be a segment of any one of these four gp40 peptide sequences that contains the core residues CNQNQFFC (SEQ ID NO:3). Such peptides contain an internal disulfide loop that maintains the immunogenic conformation of the corresponding region in native gp40. An exemplary gp40 capture reagent is a peptide (i.e., IRG2) consisting of amino acid residues CELGCNQNQFFCK (SEQ ID NO:2). This peptide has an internal disulfide bond formed by residues 5 and 12 during chemical synthesis. The cysteine residue at the amino terminal is not part of the corresponding native IDP, but is introduced to enable conjugation. For instance, the peptide can be linked via this cysteine to, e.g., bovine serum albumin (“BSA”), which can in turn be covalently attached or adsorbed to a solid surface. The carboxy terminus of IRG2 is optionally amidated to mimic the natural state of the carboxy terminus of IRG2. The capture polypeptides can additionally contain an artificial epitope tag such as FLAG™ to facilitate purification and identification of the polypeptides. Of course, it is preferred that this epitope tag is not normally encountered by felines so that it does not cause cross-reactivity in the immunoassay. Protein tags such as β-galactosidase can be used as well (see, e.g., Mermer et al., Veterinary Immunology and Immunopathology 35:133-141, 1992). Antibodies bound to the capture reagents on a solid support can be detected by an antibody-binding detection composition. This composition may include detection polypeptides that contain immunogenic sequences of p55 or gp130. For instance, disrupted FIV spiked with an immunogenic fragment of gp130 can be used as a detection composition. These antigens are linked to a detectable moiety such as a radionuclide (e.g., 125 I and 35 S), a fluorophore (e.g., fluorescein, phycoerythrin, Texas Red, or Allophycocyanin), or an enzyme that catalyzes a colorimetric or chemiluminescence reaction (e.g. horseradish peroxidase and alkaline phosphatase). In one embodiment, the test sample is contacted with the labeled antigens while or prior to being applied to a solid phase. Alternatively, the labeled antigens are applied to the solid surface after the target antibody is bound. In any event, a complex will be formed on the solid surface by the target antibody, the labeled antigen, and the immobilized antigen. After unbound labeled antigens are washed away, signal generated from the solid surface is determined as an indication of the presence of bound antibody. Polypeptides used as capture or detection reagents can be from natural FIV, or obtained by e.g., recombinant techniques or chemical synthesis. Nucleic acid constructs for expressing such polypeptides can be prepared by standard techniques such as polymerase chain reaction based on identified FIV nucleic acid sequences, e.g., the FIV genomic sequence disclosed in Talbott et al., Proc. Natl. Acad. Sci. USA 86:5743-5747, 1989. The following example is meant to illustrate the methods and materials of the present invention. Suitable modifications and adaptations of the described conditions and parameters are within the spirit and scope of the present invention. EXAMPLE Screening of FIV Antibodies Materials and Methods Disrupted FIV antigens The Crandall feline kidney (CRFK) cell line was used to propagate the Petaluma strain of FIV (O'Connor et al., J. Clin. Microbiol. 27:474-479,1989). Purified FIV was disrupted using a detergent (e.g., SDS or NP-40) and heat. Residual detergent was removed using BIO-BEADS prior to conjugation (Bio-Rad Labs, Richmond, Calif.). Recombinant p24 The gene for p24 was amplified by the polymerase chain reaction (“PCR”) from lysates of FIV Petaluma-infected CRFK cells. Primers were based on the published sequence (Talbott et al., Proc. Natl. Acad. Sci. USA 86:5743-5747, 1989). PCR products were cloned into pUC19, and inserts with verified DNA sequence were transferred to the appropriate pEX vector (Boehringer-Mannheim, Indianapolis, Ind.) to allow for synthesis of a β-galactosidase-p24 fusion protein (i.e., EXP24) in E. coli N48 30-1 (Boehringer-Mannheim). Expression of the proteins was induced by incubation of 42° C. for 2 hours. The β-galactosidase fusion protein was purified from bacterial lysates as insoluble inclusion bodies by sonication and centrifugation as described previously (Hoppe et al., Biochemistry 28:2956-2960, 1989; Wingender et al., J. Biol. Chem. 264:4367-4373, 1989). Purity was assessed after Coomassie blue staining of SDS polyacrylamide gels by inspection or densitometry after PhastSystem (Pharmacia, Piccataway, N.J.) electrophoresis. ELISA ELISA analysis was performed by substitution of the recombinant antigens for the solid-phase whole virus antigen in the PETCHEK and SNAP assays (IDEXX Laboratories; see also Mermer et al., supra). Capture Composition The capture composition in the ELISA assays contained IRG2 and EXP24, where IRG2 was conjugated to BSA via SMCC. BSA-IRG2 and EXP24 were immobilized by passive adsorption onto a polystyrene solid surface at 2 μg/ml and 5 μg/ml, respectively. Detection Composition IRG2 was conjugated to horseradish peroxidase via SMCC. Disrupted native FIV was coupled to horseradish peroxidase via periodate chemistry. The mixture of the two conjugates at an approximate molar ratio of 1:1 were used as detection reagent. Results To test whether the BSA-IRG2/EXP24 capture composition can specifically detect antibody to gp40, a microplate ELISA was performed. Briefly, the inner walls of microwells in a microplate were coated with the capture composition. Fetal bovine serum (“FBS”) containing various concentrations of an anti-gp40 mAb, i.e., mAb 2F11 or mAb 1C9, was then added to the wells. FBS containing an mAb to p27 of feline leukemia virus (mAb A2; see Lutz et al., J. Immunol. Meths. 56:209-220, 1983) was used as a negative control. IRG2 conjugated to horseradish peroxidase was used to detect anti-gp40 antibody that had bound to the wells. The results shown in Table 1 demonstrate that the p24/gp40 microplate ELISA can specifically detect anti-gp40 antibodies. TABLE 1 [mAb] A2 2F11 1C9 100 μg/ml  0.038 0.465 1.291 50 μg/ml 0.062 0.415 1.421 10 μg/ml 0.039 0.159 2.617  5 μg/ml n/d* 0.094 1.726  0 μg/ml 0.044 0.044 0.044 *not determined. Samples from 509 U.S. felines at risk for FIV infection were then screened for antibodies to p24 or to gp40. To detect antibodies to p24, PETCHEK (Mermer et al., supra) and SNAP, both of which are kits commercially available from IDEXX Laboratories (Westbrook, Me.), were used. To detect antibodies to gp40, WITNESS, a kit commercially available from Synbiotics Corporation (San Diego, Calif.), was used. A combination of the results obtained from both types of tests showed a prevalence of 13.8% (70/509) FIV-positive samples. Of these 70 FIV-positive samples, 4 of them (5.7%) reacted only with p24 or gp40 antigens in these commercial tests. One sample was positive only in p24-based tests, while three other samples were positive only in gp40-based tests. These discrepant samples gave positive results in ELISA, SNAP™, and Western blot analysis that detect both p24 and gp40 antibodies. This discovery demonstrates that detection of both p24- and gp40-directed antibodies is important for definitive results in FIV diagnostic tests. Notably, the 439 samples that were negative in the PETCHEK assay were also negative on the SNAP assay that detects both p24 and gp40 antibodies. Thus, without wishing to bind ourselves to a specific theory (which is not necessary to practice the invention), we propose that the use of the two markers is particularly important in that each marker indicates some samples that the other marker misses, without a corresponding loss of selectivity, i.e., without a significant increase in false positive results. Deposit Under the terms of the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purpose of Patent Procedure, the deposits of hybridomas 3H9, 1C9, 2H4 and 3H8 have been made with the American Type Culture Collection (ATCC) of Rockville, Md., USA, where the deposits were given Accession Number HB12528, HB12529, HB12530, and HB12531, respectively. Applicants' assignee, Idexx Laboratories, Inc., represents that the ATCC is a depository affording permanence of the deposits and ready accessibility thereto by the public if a patent is granted. All restrictions on the availability to the public of the materials so deposited will be irrevocably removed upon the granting of the patent. The materials will be available during the pendency of the patent application to one determined by the Commissioner to be entitled thereto under 37 CFR 1.14 and 35 U.S.C. §122. The deposited materials will be maintained with all the care necessary to keep it viable and uncontaminated for a period of at least five years after the most recent request for the furnishing of a sample of the deposited materials, and in any case, for a period of at least thirty (30) years after the date of deposit or for the enforceable life of the patent, whichever period is longer. Applicants' assignee acknowledges its duty to replace the deposits should the depository be unable to furnish a sample when requested due to the condition of the deposits. OTHER EMBODIMENTS It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. For example, polypeptides used to capture p24 and gp40 respectively can be immobilized in separate regions of a solid surface, where the detection of bound antibody in either region indicates that the feline donor of the test sample is infected with FIV. Other aspects, advantages, and modifications are within the scope of the following claims. 3 1 12 PRT Feline immunodeficiency virus 1 Glu Leu Gly Cys Asn Gln Asn Gln Phe Phe Cys Lys 1 5 10 2 13 PRT Feline immunodeficiency virus 2 Cys Glu Leu Gly Cys Asn Gln Asn Gln Phe Phe Cys Lys 1 5 10 3 8 PRT Feline immunodeficiency virus 3 Cys Asn Gln Asn Gln Phe Phe Cys 1 5

Methods for determining whether a feline is infected with feline immunodeficiency virus (“FIV”). The methods involve the use of an antibody-binding composition that includes two enhanced polypeptides, one containing an immunogenic fragment of the FIV gag precursor p55 and the other containing an immunogenic fragment of the FIV env precursor gp130. Also featured are devices for practicing these methods.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of the U.S. National Stage designation of co-pending International Patent Application PCT/EP2003/050782 filed Nov. 3, 2003, which claims priority to U.S. provisional application No. 60/424,681 filed Nov. 8, 2002 and European patent application no. 02405995.8 filed Nov. 19, 2002, and the entire contents of these applications are expressly incorporated herein by reference thereto. FIELD OF THE INVENTION [0002] The invention relates to a method of operating a gas turbine power plant and a gas turbine power plant. BACKGROUND OF THE INVENTION [0003] In the last years different projects were launched with the aim to develop emission free gas turbine based processes using semi-closed cycles with CO 2 /H 2 O mixtures as working fluid. Methods of operating such power plants are known for example from EP-A1-0 939 199 and EP-A1-0 953 748. In these processes the fuel, usually natural gas, reacts with technically pure oxygen generated either in an external air-separation unit or internally in an integrated membrane reactor. One major disadvantage of using air-separation units for these kind of processes is that they consume a great amount of energy, thus penalizing the efficiency and power output of the plant. From the literature it can be found that the energy demand for air-separation units is as high as 0.3 kWh/kg O 2 produced. The energy consumption for separating the oxygen from the air can be decreased very much if oxygen-separating membranes are used. Also this technique has a few disadvantages, namely: metal to ceramic sealing is needed that can withstand temperatures >800° C., the turbine inlet temperature (TIT) and the ceramic sealing temperature are linked, which limits the maximum TIT and thus lowers the performance of the plant and one needs to separate large amounts of air, corresponding to the total O 2 required for full oxidation of fossil fuel powering the gas turbine. SUMMARY OF THE INVENTION [0004] The present invention relates to providing a method of operating a gas turbine power plant and a gas turbine power plant which avoid disadvantages of the prior as well as increasing the overall efficiency of the power plant. [0005] This present invention is related to making use of so-called partial oxidation (POX) of the natural gas to syngas consisting of CO and H 2 . The oxygen required for this partial oxidation is provided by a ceramic, air separation membrane, thermally integrated into the process. This syngas would then be water gas shifted to produce even more hydrogen and convert the CO to CO 2 , and finally use the produced hydrogen as fuel in a gas turbine. [0006] By doing this, one would overcome the temperature limit previously set by the membrane. The membrane reactor unit would be combined to both work as an oxygen transferring membrane and as a reactor for the partial oxidation. One membrane type that can be used to separate the oxygen from the air is a so-called “Mixed Conducting Membrane” (MCM). These materials consist of complex crystalline structures, which incorporate oxygen ion vacancies (5-15%). The transport principle for oxygen transport through the membrane is adsorption on the surface followed by decomposition into ions, which are transported through the membrane by sequentially occupying oxygen ion vacancies. The ion transport is counterbalanced by a flow of electrons in the opposite direction completing the circuit. The driving force is a difference in oxygen partial pressure between the permeate and retentate sides of the membrane. The transport process also requires high temperatures, i.e. >700° C. In an embodiment of the present invention the surfaces of the permeate side of the membrane that contain the syngas are coated with catalytic material to promote the formation of synthesis gas 17 1 and, in particular, hydrogen. Catalyst materials used for autothermal reforming are Rh, Ru, Co, Fe or bimetallic combinations thereof. [0007] Optionally, prior to entering the membrane reactor, the air stream from the compressor can be lead to a catalytic burner where the air is heated by means of catalytic combustion. The fuel for the catalyst is either hydrogen or natural gas. Thereby the use of hydrogen is preferred to avoid producing CO 2 . The reason for using a catalytic burner is to increase the average temperature in the membrane/POX reactor thereby increasing the oxygen flux through the membrane. Also, the temperature gradient in the reactor will be lower and thus the thermal stresses for the reactor will decrease. [0008] Advantageously the syngas coming from the membrane/POX reactor consisting of hot steam, H 2 and CO can enter a low temperature heat exchanger, where the syngas mixture is cooled down by an incoming stream of the compressed air from the compressor. Another possibility would be to use a medium temperature heat exchanger to raise the temperature of the mixture of steam and natural gas before the mixture enters the membrane/POX reactor. This would flatten out the temperature profile in the membrane/POX reactor and thus lower the temperature gradients in this. [0009] After the expansion the hot flue gases of the gas turbine can be utilised in a heat recovery steam generator producing steam for the bottoming steam cycle and producing more power in a steam turbine and electricity in a generator. BRIEF DESCRIPTION OF THE DRAWINGS [0010] Preferred embodiments of the invention are illustrated in the accompanying drawings, in which: [0011] FIG. 1 illustrates a gas turbine power plant according to the present invention; and [0012] FIG. 2 illustrates the partial oxidation of the membrane/partial oxidation reactor. [0013] The drawings show only the parts important for the invention. Same elements will be numbered in the same way in different drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0014] FIG. 1 shows a syngas based low emission power plant according to the present invention. Air 1 is fed through a compressor 2 before the compressed air 3 is fed at least through a membrane/partial oxidation (POX) reactor 4 . After the membrane/POX reactor 4 the air is burned in a combustion chamber 5 together with hydrogen 6 . The flue gases are then expanded in a turbine 7 , which is driving the compressor 2 and producing electricity in a generator 8 . After the expansion the hot flue gases 9 are utilised in a heat recovery steam generator 10 producing steam for the bottoming steam cycle 11 and producing more power in a steam turbine 12 and electricity in a generator 13 . [0015] As can be seen from FIG. 1 , natural gas 14 is being mixed with superheated intermediate pressure steam 15 and is then lead to the membrane/POX reactor 4 . One possibility here would be to use a medium temperature beat exchanger 16 to raise the temperature of the mixture of steam 15 and natural gas 14 . This would flatten out the temperature profile in the membrane/POX reactor 4 and thus lower the temperature gradients in this. Since the temperature involved is not too high (<900° C.), it might be possible to use a metal heat exchanger. [0016] As seen in FIG. 2 , in the membrane/POX reactor 4 , oxygen is transferred through a membrane 18 from a first side to a second side and is partially oxidised (as well as reformed with steam) on the membrane 18 surface with the natural gas 14 by the following reactions: CH 4 +0.5O 2 2H 2 +CO+35.67 kJ/mol CH 4 +H 2 O CO+3H 2 −205 kJ/mol CO+H 2 O CO 2 +H 2 +41.15 kJ/mol [0017] In sum, the three reactions combine to produce a mixture of H 2 , CO and CO 2 ; the overall heat balance and product mixture is dictated by the amount of oxygen (and endothermic reactions) that is present. The design of the membrane/POX reactor 4 is such that the overall process is autothermal, and the membrane temperature is of ca. 800° C. The membrane/POX reactor 4 would be combined to both work as an oxygen transferring membrane and as well as doing the partial oxidation. One membrane type that can be used to separate the oxygen from the air is a so-called “Mixed Conducting Membrane” (MCM). These materials consist of complex crystalline structures, which incorporate oxygen ion vacancies (5-15%). The transport principle for oxygen transport through the membrane 18 is adsorption on the surface followed by decomposition into ions, which are transported through the membrane by sequentially occupying oxygen ion vacancies. The ion transport is counterbalanced by a flow of electrons in the opposite direction. The driving force is a difference in oxygen partial pressure between the permeate and retentate sides of the membrane 18 . The transport process also requires high temperatures, i.e. >700° C. In an embodiment of the present invention the surfaces of the permeate side of the membrane 18 (that containing the syngas 171 ) is coated with catalytic material to promote the formation of synthesis gas 171 and, in particular, hydrogen. Catalyst materials used for autothermal reforming are Rh, Ru, Co, Fe or bimetallic combinations thereof (e.g. Co/Fe). [0018] The syngas 17 1 , now consisting of hot steam, H 2 and CO enters a low temperature heat exchanger 19 , where the syngas 17 1 mixture is cooled down by an incoming stream of the compressed air 3 from the compressor 2 . Optionally, the air stream from the low temperature heat exchanger 19 can then be lead to a catalytic burner 20 where the air is heated by means of catalytic combustion. The fuel for the catalytic burner 20 is either hydrogen 21 or natural gas 14 . Use of hydrogen 21 is preferred to avoid producing CO 2 . The reason for using a catalytic burner 20 is to increase the average temperature in the membrane/POX reactor 4 , increasing the oxygen flux through the membrane 18 . Also, the temperature gradient in the reactor 4 will be lower and thus the thermal stresses for the reactor 4 will decrease. This catalytic burner 20 can also be used to help control process conditions within the MCM reactor during start up or to address instabilities within the membrane/POX reactor 4 associated with the autothermal reforming and potential catalyst deactivation. The temperature of the MCM reactor will be very sensitive to the amount of O 2 present and there could be some strange transients during start up. A quick reacting catalytic burner 4 running on H 2 could help for process control. [0019] After the syngas 17 has been cooled down in the low temperature heat exchanger 19 , the syngas 17 1 is then further cooled down in a CO shift reactor 22 , lowering the temperature further to about 200-300° C. Depending on the chosen cooling temperature, water will condense out or not. Since a low temperature favors the CO shift reaction it might be wise to keep the temperature low. This will also lower the water consumption for the cycle since the condensed water 23 can be re-injected in the bottoming steam cycle 11 . The medium used for the cooling is boiler feed water 24 1 , 24 2 from a bottoming steam and water cycle 11 . During the cooling of the syngas 17 , in the CO shift reactor 22 , the syngas 17 1 undergoes the following reaction: CO+H 2 O H 2 +CO 2 +41.15 kJ/mol [0020] The CO shift reactor 22 is in other words used to convert CO and water to CO 2 and more hydrogen. Also this reaction is mildly exothermic, leading to some of the water which was condensed out during the cooling (or all water if the cooling temperature is high) being evaporated again, taking heat from the exothermic process described above. After the CO shift reactor 22 the syngas 17 2 consists ideally of H 2 , CO 2 and H 2 O. This syngas 17 2 is then lead to some kind of CO 2 absorption equipment 25 , based on either chemical or physical absorption. The CO 2 removal rate in this kind of equipment is around 90%. Low pressure steam 26 needed for the CO 2 removal is extracted from the steam turbine 12 , and the condensed water 27 is lead back to the feed water tank of the steam cycle 11 . The removed CO 2 28 is further compressed by means of inter-cooling in a compressor 29 , producing liquid CO 2 30 that might be deposited or used in for instance enhanced oil recovery. [0021] After removing most of the CO 2 , the syngas 17 3 mainly consisting of H 2 , H 2 O and some remaining CO 2 is lead to a combustion chamber 5 , to be burned together with air from the first side of the membrane/POX reactor 4 . The water in the syngas 17 3 helps control the combustion temperature and thus lowers NO x formation. A part of the resulting syngas 17 3 comprising hydrogen 6 from the CO 2 removal equipment 25 can as well be burned in the catalytic burner 20 . LIST OF DESIGNATIONS [0000] 1 Air 2 Compressor 3 Compressed air 4 Membrane/partial oxidation (POX) reactor 5 Combustion chamber 6 Hydrogen 7 Gas turbine 8 Generator 9 Hot flue gases 10 Heat recovery steam generator 11 Bottoming steam cycle 12 Steam Turbine 13 Generator 14 Natural gas 15 Superheated steam 16 Medium temperature heat exchanger 17 1 , 17 2 , 17 3 Syngas 18 Membrane 19 Low temperature heat exchanger. 20 Catalytic burner 21 Hydrogen 22 CO shift reactor 23 Condensed water 24 Boiler feed water 25 CO 2 absorption equipment 26 Low pressure steam 27 Condensed water 28 . CO 2 29 compressor 30 liquid CO 2

A method of operating a gas turbine power plant and gas turbine power plant are disclosed wherein hydrogen for the combusting process is produced by feeding natural gas mixed with steam through a membrane/partial oxidation reactor and converting the natural gas at least to H 2 and CO. Thereby oxygen is transferred from the compressed air through the membrane of the membrane/partial oxidation reactor and the oxygen is used for the partial oxidation process of the natural gas. The process is followed by converting the syngas in a CO shift reactor and a CO shift reactor to a CO 2 removal equipment to mainly hydrogen.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to devices for assisting the physically challenged, and more particularly, to a rotational transfer apparatus by which a wheelchair-bound individual may be transferred to or from the wheelchair from a variety of other locations, including, but not limited to, a commode, bed or sofa. 2. Description of the Prior Art Devices for rotating an individual with the intent of transferring that individual from one point to another in the form of a rotating transfer apparatus are known in the art of medical devices. U.S. Pat. No. 2,757,388 issued to Chisholm discloses a bedside transfer stand. This device would assist a person in the procedure of bed to wheelchair transfers. This device is non-adjustable in vertical height, and does not include an efficient means of assisting someone who is more seriously disabled into an upright position. This device also does not include generally rectangular cut-outs or rectangular apertures in its base designed to receive the wheels of the wheelchair. U.S. Pat. No. 2,963,713 issued to Forrest discloses an invalid transfer apparatus. This apparatus is vertically adjustable to accommodate any size user. This device does not include an efficient means of assisting someone who is more seriously disabled into an upright position. Also, this device does not include generally rectangular cut-outs or rectangular apertures in its base that are designed to receive the wheels of the wheelchair. U.S. Pat. No. 4,279,043 issued to Saunders discloses a transfer stand. This stand includes wheels in the form of castors, a provision to convert the device into a wheelchair, and a means to incorporate vertically adjustable crutches. This device does not include an efficient means of assisting someone who is more seriously disabled into an upright position. This device also does not include generally rectangular cut-outs or apertures in its base that are designed to receive the wheels of the wheelchair. Thus, while the foregoing body of prior art indicates it to be well known to use rotatable transfer devices, the provision of a device which more completely assists in the patient transfer which is simple and cost effective is not contemplated. The prior art described above does not teach or suggest a transfer device which incorporates elastic elements attached to the body of the device as well as the patient which assists the patient into acquiring a standing position within the patient transfer stand. The prior art devices do not include a band structure which is connected to the transfer device for retaining and securing the patient in such a manner to insure safety and stability during the transfer process. The prior art devices also do not contemplate the incorporation of apertures, slots or rectangular cutouts in the turnable base that would receive the wheels of a wheelchair. The foregoing disadvantages are overcome by the unique elastic bands and rectangular cutouts of the present invention, as will be made apparent by the following description thereof. Other advantages of the present invention over the prior art will also be rendered evident. SUMMARY OF THE INVENTION To achieve the foregoing and other advantages, the present invention, briefly described, provides a patient transfer stand for assisting a wheelchair-bound person in transferring to and from a wheelchair to and from a variety of other points in a simple and assisted fashion. Generally speaking, those confined to wheelchairs (those who would be utilizing the patient transfer stand) may not possess the physical prowess required to lift themselves upright without assistance. The transfer stand includes a base that rotates. The base is notched or contains cut-outs in order to receive and accommodate the wheels of the wheelchair. The base supports a pair of vertical support bars and elevated handle structure that the wheelchair-bound person can hold onto during transfer. The elevated handle structures include elastic straps, which may be referred to as assist bands, for assisting the wheelchair-bound person from the wheelchair into the patient transfer stand. The elastic straps also help the patient return to a sitting position by slowing their rate of descent during the act of sitting. The straps are attached to a belt or harness worn by the person, allowing the elastic or spring force to help pull them up and to acquire a standing position inside the transfer stand. Hand holds or handles are provided on the transfer stand for the person to hold onto while they are in a raised, semi-standing or standing position. Once the person is on the transfer stand, the stand is rotated by an assistant and then person may then sit or recline on the desired object, such as a bed or commode. A retaining band may be provided on the patient transfer stand to secure the patient in a safe and secure fashion which would prevent accidental discharge of the patient from the apparatus. It is envisioned that the patient transfer stand will be used in homes for personal use, at hospitals, nursing homes, and other institutions, including those which care for the elderly. Other uses may include permanent storage in handicapped oriented bathrooms in public areas to facilitate a wheelchair bound person to more freely utilize such facilities. The above brief description sets forth rather broadly the more important features of the present invention in order that the detailed description thereof that follows may be better understood, and in order that the present contributions To the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least the preferred embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description, and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception upon which this disclosure is based, may readily be utilized as a basis for designing other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions, insofar as they do not depart from the spirit and scope of the present invention. Further, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office as well as the public in general (especially scientists, engineers and practitioners in the art who are not familiar with patent or legal terms of phraseology) to determine the nature and essence of the technical disclosure of the application from a quick cursory inspection. Accordingly, the Abstract is neither intended to define the invention or the application, which only is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. It is therefore an object of the present invention to provide a new and improved patient transfer stand which has all of the advantages of the prior art and none of The disadvantages. It is another object of the present invention to provide a new and improved patient transfer stand which may be easily and efficiently manufactured and marketed. It is a further objective of the present invention to provide a new and improved patient transfer stand which is of durable and reliable construction. An even further object of the present invention is to provide a new and improved patient transfer stand which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such patient transfer stand available to the buying public. Still yet a further object of the present invention is to provide a new and improved patient transfer stand in which elastic strap means are provided to assist the patient into acquiring a raised, semi-standing or standing position on the patient transfer stand if such assistance is required or desired by the patient. It is still a further object of the present invention to provide a new and improved patient transfer stand includes a waist belt or patient transfer belt secured to the patient allowing the patient to remain secure in the patient transfer apparatus during the complete transfer process, i.e. the raising and turning. A further object of the present invention is to provide a new and improved patient transfer stand including means for permitting the wheelchair to approach and interact the apparatus, by providing cut-out sections in the base of the apparatus designed to receive the wheels of the wheelchair thus permitting the patient to develop leverage during the raising procedure. These together, with still other objects of the invention--including means for establishing positive structural integrity and greater loadbearing capacity than other prior art devices--along with 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 the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and the above objects as well as objects other than those set forth above will become more apparent after a study of the following detailed description thereof. Such description makes reference to the annexed drawings wherein: FIG. 1 is a perspective view showing the preferred embodiment of the patient transfer stand of the invention. FIG. 2 is a partial exploded view showing the generally X-shaped bottom element of the patient transfer stand with the associated rotating bearing structure. FIG. 2A is a side view of the generally X-shaped bottom element and the associated rotating bearing structure and the rotating plate structure of the patient transfer stand. FIG. 2B is a view of the base of the patient transfer stand showing a configuration of the skid members. FIG. 3 is a side view of the patient transfer stand. FIG. 3A is an exploded view of the telescoping vertical adjustment means of the patient transfer stand. FIG. 3B is an exploded view of the telescoping adjustment means of the U-shaped hand grip handle. FIG. 4 is a view of the elastic assist band of the instant invention. FIG. 5 is a view of the patient transfer belt with a clip for attaching the assist bands of the instant invention. FIG. 5A is a view of the clip which receives a patient transfer belt and is attached to the assist bands of the instant invention. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to the drawings, a new and improved patient transfer stand embodying the principles and concepts of the present invention will be described. Turning initially to FIGS. 1, 2, 2A, and 2B there is shown a first exemplary embodiment of the patient transfer stand apparatus of the instant invention generally designated by reference numeral 10. In its preferred form, the patient transfer stand 10 comprises generally a X-shaped base 12 which has a turning means 15 mounted centrally thereon. Arrow 15A indicates the direction of rotation of the turning means 15. The turning means 15 may be a race of bearings, or any other suitable turning means 15. The turning means 15 is sandwiched between the X-shaped base 12 and a E-shaped patient stand 14. The E-shaped patient stand 14 is a plate-like structure that the person can stand on while being transferred to or from the wheelchair. Nylon skids 14A are provided intermediate the X-shaped base 12 and stand 14 which stabilize the platform in regards to tilting. There are two cutouts or openings in the E-shaped patient stand 14, a left opening 50 and a right opening 52, these cutouts are located on the front portion 11 of the E-shaped patient stand 14. The left opening 50 and the right opening 52 are designed to receive the wheels of the wheelchair. This permits the wheelchair-bound person to bring the wheelchair closer to the patient transfer apparatus 10 then in prior art devices. A right vertical tube 16 and a left vertical tube 18 extend vertically from the rear portion 13 of the E-shaped patient stand 14 and are connected thereto. A right wheel 26 is connected to the right vertical tube 16 and a left wheel 28 is connected to the left vertical tube 18. Wheels mobilize the structure, giving the patient transfer stand an ease of motion. A right kickplate support tube 20 has a generally L-shaped configuration. It is connected to the right portion 27 of the E-shaped patient stand 14 at point 20A. The right kickplate support tube 20 is also connected to the right vertical tube 16 at point 20B. The right kickplate support tube 20 defines a plate support structure and receives a right kickplate 21. The right kickplate 21 is orientated vertically. A left kickplate support tube 24 has a generally L-shaped configuration. It is connected to the left portion 29 of the E-shaped patient support stand 14 at point 24A. The left kickplate support tube 24 is also connected to the left vertical tube 18 at point 24B. The left kickplate support tube 24 defines a plate support structure and receives a left kickplate 25. The left kickplate 25 is orientated vertically. A rear kickplate support tube 22 is a generally straight section of tube. The rear kickplate support tube 22 is connected to the right vertical tube 16 at point 22A. The rear kickplate support tube is also connected to the left vertical tube 18 at point 22B. The rear kickplate support tube 22 is in parallel relation to the E-shaped patient stand 14. The rear kickplate support tube 22, the right vertical tube 16, the left vertical tube 18 and the rear portion 13 of the E-shaped patient support stand 14 defines a plate support structure and receives a rear kickplate 23. The rear kickplate 23 is orientated vertically. A semi-circular opening 19 is located in the rear kickplate 23. This opening 19 permits the assistant to insert a foot to activate plate lock 5. Plate lock 5 utilizes a plunger mechanism which secures the stand 14 to the base 12. The assistant can disengage the plate lock 5 by depressing a deactivating switch located on the plate lock 5. The right kickplate support tube 20, the rear kickplate support tube 22, and the left kickplate support tube 24 all lend to the structural stability of and permit increased loads to be carried by, the patient transfer apparatus 10. A right structural support tube 30 is connected to the L-shaped right kickplate support tube 20 at point 30A. The right structural support tube 30 is also connected to the right vertical tube at point 30B. A left structural support tube 32 is connected to the L-shaped left kickplate support tube 24 at point 32A. The left structural support tube 32 is also connected to the left vertical tube 18 at point 32B. Both the right structural support tube 30 and the left structural support tube 32 lend structural integrity and increased loadbearing to the patient transfer apparatus 10. The right vertical tube 16 and the left vertical tube 18 are connected at the top of the patient transfer apparatus 10 by a top horizontal tube 17. The top horizontal tube 17 is orthogonally orientated to both the right vertical tube 16 and the left vertical tube 18. The top horizontal tube 17 is in parallel relation to the E-shaped patient support stand 14 and the rear kickplate support tube 22. The top horizontal support tube 17 is coplanar with the rear kickplate support tube 22. A U-shaped hand grip handle 38 is connected to the top horizontal tube at a point 38A which is proximal to the right support tube 16 and at a point 38B which is proximal to the left support tube 18. The hand grip handle 38 is telescopically adjustable as is best shown in FIG. 3B. A plurality of apertures (A) are provided on the hand grip handle 38 which would receive a mechanical device, the mechanical device would secure the hand grip handle at a specific length. The hand grip handle 38 is identical on both the right side 38A and the left side 38B in regards to the telescopic adjustment means. This handle is designed to allow the person who is being transferred to have something to hold onto at a proper height to develop and utilize the required leverage to be able to lift and stabilize themselves during the transfer process. A generally U-shaped right stabilizing bar 34 is provided proximal the top of the patient transfer apparatus 10. A generally U-shaped left stabilizing bar 36 is provided proximal the top of the patient transfer apparatus 10. A first horizontal tube 44 is connected to the right stabilizing bar 34 top leg 34A and to the left stabilizing bar 36 top leg 36A. A second horizontal tube 42 is connected to the right stabilizing bar 34 bottom leg 34B and to the left stabilizing bar 36 bottom leg 36B. The first horizontal tube 44 and the second horizontal tube 42 are in parallel relation with each other and the top horizontal tube 17. A panel 40 is supported between the first horizontal tube 44 and the second horizontal tube 42. This panel 40 prevents objects from penetrating the internal area of the patient transfer apparatus 20, preventing injury or other mishaps. The first horizontal tube 44, the second horizontal tube 42 and the right stabilizing bar 34 and the left stabilizing bar 36 may be an integral, bent, generally rectangular (prior to bending), section of tubing. This section of tubing also lends structural support to the patient transfer apparatus 10. A right elastic assist band 46 is connected to the lower leg 34B of right stabilizing bar 34. A left elastic assist band 48 is connected to the lower leg 34B of left stabilizing bar 36. The right elastic assist band 46 and left elastic assist band 48 are made of an elastic material and are designed to be attached to a harness or belt 70 which is worn by the patient by a right attachment element 46A and a left attachment element 48A. As best shown in FIGS. 4, 5, and 5A, the patient transfer belt 70 has a plurality of clip members 72 attached thereto. A central hook 74 is located on the clip member 72. The attachment elements, 46A and 48A, respectively, will attach to the central hook 74 of the clip 72. A plurality of clips 72 may be provided, equal to the number of assist bands employed. The right elastic assist band 46 is attached to element 34B by attachment hook 46B. The left elastic assist band 48 is attached to element 36B by attachment hook 48B. The patient would utilize self developed leverage, through the physical and mechanical relationship between the hand grip handle 38, the rear kick plate 23 and the right elastic band 46 and the left elastic band 48 when acquiring a raised position and would have a force imparted to them by the elastic bands. This force would help them acquire a raised position and assist them in mounting the patient transfer apparatus 10. It should be appreciated that when sitting, after the patient transfer stand 10 has been rotated that the elastic assist bands impart a force against the sitting motion, allowing the patient to sit in a more controlled and safe fashion. The elastic material may be neoprene, or any other elastic material with an appropriate modulus of elasticity. Referring now to FIGS. 3 and 4, the patient transfer apparatus 10 is shown. The top section 60 of the right vertical tube 16 is telescopically adjustable with the lower section 62 of the right vertical tube 16. The patient transfer apparatus 10 is symmetrical about the z-axis, therefore there exists an identical telescoping structure on the left vertical tube 18 which is not shown in the figures. Apertures 64 are designed to receive a mechanical device to maintain the vertical tube at an appropriate height for different sized individuals. Both the top section 60, and the lower section 62 have apertures located thereon. The top section 60 acts as the female section and the lower section acts as the male section in the telescoping relationship which is developed between the two elements. The mechanical device will have a locking feature which will guarantee its placement and prevent its accidental disengagement. It is proposed that the tube structure be manufactured from a sturdy and reasonably inexpensive material, such as 6061 T-6 Aluminum tubing. It is to be understood; however, that any type of aluminum or other metals including steel may be utilized in the tubular construction. Certain plastics may also have the required material properties which would permit them to be utilized as the tubing material as well. The tubing connections may be made by mechanical fasteners, by welding, by braising or by extruding sections as continuous tubing elements. METHOD OF USING THE PATIENT TRANSFER STAND The method of operation of this device is as follows from a wheelchair to a bed. First, the device is adjusted in appropriate manner to reflect the height of the patient. The wheelchair is brought into proximity of the apparatus, the wheelchair's wheels to be received in the left opening 50 and right opening 52 respectively. The patient braces his feet between the E-shaped patient stand 14 and the rear kickplate 23 in a wedge type fashion. The patient reaches up, and then depending on the severity of their condition, the right assist band 46 and the left assist band 48 would be attached to a belt or harness structure 70 which has a plurality of clips 72 attached thereto. The belt or harness structure 70 would be attached about the patient. A central hook 74 is located on each clip 72. The assist bands (46, 48) are attached to the central hooks 74 by a right attachment element 46A and a left attachment element 48A. The patient grabs the left stabilizing bar 36 and the right stabilizing bar 34 and utilizing leverage, as well as the force imparted to the patient by the elastic spring properties of the right assist band 46 and left assist band 48 stands up in a raised, semi-standing or erect fashion within the patient transfer stand 10. The assist bands (46, 48) will be primarily be utilized by those persons who are too weak to utilize the leverage as the sole means of standing erect. It is to be appreciated that the majority of patients may not need the assist bands. At this point the patient is then rotated away from the position of the wheelchair in such a fashion to place the bed right behind the patient. At this point the patient would sit down, the assist bands (46, 48) providing an oppositely directed reaction force which permits the patient to sit in a controlled and safe manner on the bed. The assist bands and the patient transfer belt are then removed and the patient reclines in the bed. It is to be appreciated that the patient transfer stand 10 may employ more than two assist bands. Through utilization of more assist bands, patients of greater weight may be assisted in acquiring a transfer position in the transfer stand, and then returned to a sitting position in a safe and controlled fashion. The harness or belt described herein, to which the assist bands would be attached includes a plurality of clip members 72 which employ a central hook 74 which attach to the transfer belt 70. The central hooks 74 would provide attach points for the assist bands, allowing one to accommodate patients of any size, weight and strength. The reverse of the aforementioned procedures would permit the patient to be transferred from the bed to the wheelchair. It is apparent from the above that the present invention accomplishes all of the objectives set forth by providing a new and improved patient transfer apparatus incorporating means to transfer a patient in a safe and efficient manner, notwithstanding the patient's physical strength. With respect to the above description, it should be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to those skilled in the art, and therefore, all relationships equivalent to those illustrated in the drawings and described in the specification are intended to be encompassed only by the scope of appended claims. While the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment of the invention, it will be apparent to those of ordinary skill in the art that many modifications thereof may be made without departing from the principles and concepts set forth herein. Hence, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications and equivalents.

A patient transfer stand is provided for assisting a wheelchair-bound person to transfer to and from a wheelchair to a variety of other points in a simple fashion. The transfer stand includes a rotating base. The base includes 2 substantially rectangular cut out portions that accommodates the wheels of the wheelchair. The base supports a pair of vertical support bars, in addition to an elevated handle structure that the wheelchair-bound person can hold onto during transfer. The elevated handle structures include elastic straps which may be used to assist the wheelchair-bound person from the wheelchair into the patient transfer stand. A patient, if required, may utilize the elastic straps attached to a belt or harness worn about the waist to assist them in assuming a standing position inside the transfer stand. Through the utilization of developed leverage, the patient may assume a raised or semi-standing position in the transfer stand without assistance. The patient may also use hand holds or handles while they are assuming the standing position. Once the patient has assumed the upright position on the transfer stand, the stand is rotated and the person may sit or recline on the desired object--such as the bed or commode. A means to secure the person inside the transfer stand during transfer may also be provided.

BACKGROUND OF THE DISCLOSURE The present invention relates to viscous fluid couplings, and more particularly, to such couplings which are used to drive vehicle radiator cooling fans, wherein the engagement or disengagement of the viscous fluid coupling may be controlled in response to a remotely sensed condition, such as coolant temperature. A viscous fluid coupling (viscous fan drive) of the general type to which the present invention relates is illustrated and described in U.S. Pat. No. 3,055,473, assigned to the assignee of the present invention, and incorporated herein by reference. A typical viscous coupling receives input drive torque from a vehicle engine, and transmits output drive torque to a radiator cooling fan. The conventional viscous coupling includes an output coupling defining a fluid chamber, valve means operable to separate the fluid chamber into a reservoir chamber and an operating chamber, and an output coupling rotatably disposed in the operating chamber and operable to transmit input drive torque to the output coupling in response to the presence of viscous fluid in the operating chamber. The valve means includes a valve member moveable between a closed position blocking fluid flow into the operating chamber, in an open position permitting fluid flow into the operating chamber. In certain vehicle applications, it has become desirable to sense directly some parameter of the vehicle, such as the temperature of the liquid coolant entering the radiator ("top-tank" temperature), and to control the viscous fan drive in response to changes in that parameter. One benefit of the arrangement described is that the responsiveness of the fan drive is improved, when compared to the earlier, prior art fan drive which was responsive only to sensed ambient air temperature. Accordingly, the conventional fan drive described above has been modified by the addition of an actuator means operable to move the valve member between the closed position and the open position in response to changes in an input signal. Such a "remote sensing" viscous coupling is illustrated and described in U.S. Pat. No. 5,152,383, assigned to the assignee of the present invention and incorporated herein by reference. Viscous fan drives have been extremely successful commercially for many years. However, in the course of development, testing, and operation of viscous fan drives (whether of the ambient temperature sensing type, or of the remote sensing type), there are several operating situations in which the prior art viscous fan drives have not responded adequately. One of these operating situations is referred to as the "stoplight idle" condition. When a vehicle equipped with a conventional viscous fan drive comes to rest, for example, at a traffic signal, engine speed falls below the "demanded" fan speed, i.e., the fan speed necessary to cool the engine adequately. Of course, in a conventional fan drive installation, the fan speed can never exceed the input speed (engine speed multiplied by the pulley ratio). For a remote sensing clutch with classic (prior art) feedback control, the fan drive logic will, therefore, move the valve member toward a fully open position, filling the operating chamber with fluid in a vain attempt to reach the "demanded" fan speed. A similar result occurs with ambient air sensing type clutches. In a stop light idle condition, a bimetallic control element will either not change the position of the partially open valve, or will actually move the valve further toward the open position. This is caused by heated air dissipated by the vehicle engine. Unfortunately, when the vehicle accelerates from the stopped condition at the traffic signal, the fan drive operates in a fully engaged condition, when such is not really necessary, resulting in excessive fan noise as the input speed to the fan drive increases. This undesirable noise continues until enough fluid is pumped from the operating chamber to the reservoir chamber to bring the fan drive down to the then-current demanded fan speed. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved method for controlling a viscous fluid coupling which will overcome the above-described stoplight idle condition. It is a more specific object of the present invention to provide an improved method of controlling a viscous fluid coupling which is capable of sensing the existence of the stoplight idle condition and preventing an undesirable increase in the amount of fluid in the operating chamber of the coupling. The above and other objects of the invention are accomplished by the provision of an improved method of controlling a viscous fluid coupling of the type described above. The improved method comprises the steps of: (a) sensing the speed of the vehicle engine; (b) comparing the sensed engine speed to a first limit and to a second limit, and when the engine speed is greater than the first limit, but less than the second limit, then (c) sensing the speed of rotation of the radiator cooling fan; (d) comparing the fan speed to a predetermined fan speed limit, and when the fan speed is greater than the predetermined fan speed limit; (e) modifying the input signal to move the valve member toward the closed position. The other operating condition in which the conventional viscous fan drive has not been satisfactory is the "slip heat" condition. Every viscous fluid coupling has a "slip heat" region in its graph of output speed versus input speed which represents a region of operation beyond the recommended design limits, as will be described in greater detail subsequently. When operating at an input speed and an output speed within the slip heat region, the viscous coupling generates more slip heat than the coupling can dissipate. Continued operation in the slip heat region would eventually degrade the viscous fluid and the performance of the coupling. Accordingly, it is an object of the present invention to provide an improved method of controlling a viscous fluid coupling which enables the coupling to avoid prolonged operation in the slip heat region. It is a more specific object of the present invention to provide an improved method of controlling a viscous coupling wherein, when operation in the slip heat region is sensed, or likely to occur, the speed of the output coupling is modified until the coupling is operating outside of (above or below) the slip heat region. The above and other objects of the invention are accomplished by the provision of an improved method of controlling a viscous fluid coupling comprising the steps of: (a) generating a demanded fan speed; (b) sensing the speed of the vehicle engine; (c) comparing the sensed engine speed to a first limit, and if the sensed engine speed is greater than the first limit, then (d) determining, for the particular sensed engine speed, a fan speed corresponding to a maximum safe fan speed below a slip heat region; (e) comparing the demanded fan speed to the maximum safe fan speed, and when the demanded fan speed is greater than the maximum safe fan speed; (f) sensing a temperature representative of the need for cooling and comparing the sensed temperature to a temperature high limit, and when the sensed temperature is less than the temperature high limit, setting demanded fan speed equal to the maximum safe fan speed; or (g) when the sensed temperature is greater than the temperature high limit, modifying the input signal to move the valve member toward the open position. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat pictorial side plan view of a vehicle engine cooling system of the type to which the present invention relates. FIG. 2 is a somewhat schematic view of the vehicle engine cooling system, including the control system and logic of the present invention. FIGS. 3A and 3B are somewhat schematic plan views of the fan drive valving in the closed and open positions, respectively. FIG. 4 is a logic diagram for the stoplight idle control logic of the present invention. FIG. 5 is a logic diagram for the slip heat protection logic of the present invention. FIG. 6 is a graph of fan speed, in RPM, versus input speed, in RPM, illustrating the slip heat region. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, which are not intended to limit the invention, FIG. 1 is a somewhat pictorial view of a vehicle engine cooling system of the type which may be used, by way of example only, on a truck or automobile. The system includes an internal combustion engine E and a radiator R, interconnected by hoses 11 and 13 in the usual manner. Thus, fluid coolant can flow from the engine E through the hose 11, then through the radiator R, and return through the hose 13 to the engine E. A viscous fan drive (viscous coupling), generally designated 15, includes an input shaft 17 mounted to an engine coolant pump 19 for rotation therewith. Input shaft 17 and pump 19 are driven, by means of a pair of pulleys 21 and 23, by means of a V-belt 25, as is well known in the art. An actuator assembly 27 is mounted on the front side (left-hand side in FIG. 1) of the viscous coupling 15. An input signal is transmitted to the actuator means 27 by means of a plurality of electrical leads disposed within a conduit 29, the reference numeral "29" also being used hereinafter for the input signal to the actuator means 27. Bolted to the rearward side of the viscous coupling 15 is a radiator cooling fan F, including a plurality of fan blades, also designated "F". In the subject embodiment, the viscous coupling 15 is made in accordance with the teachings of U.S. Pat. No. 5,152,383, assigned to the assignee of the present invention and incorporated herein by reference. However, it should be understood that the present invention is not limited to any particular configuration of viscous coupling, or any particular type or configuration of actuator means, except as is specifically noted hereinafter. Referring now to FIG. 2, there is illustrated a further schematic illustration of the cooling system shown in FIG. 1. As is illustrated in FIG. 2, the viscous coupling 15 includes an output coupling 31, which normally comprises a body member 33 and a cover 35. Together, the body 33 and cover 35 define an enclosed fluid chamber, which is separated by means of a valve plate 37 into a fluid operating chamber 39 and a fluid reservoir chamber 41. Disposed within the operating chamber 39 is an input coupling 43, mounted for rotation with the input shaft 17. Details of the viscous coupling 15 may be better understood by reference to the above incorporated patents. Referring now to FIGS. 3A and 3B, the valve plate 37 defines a fill opening 45, in a manner which is well known to those skilled in the art. The actuator means 27 includes a rotatable armature or shaft 47, to which is mounted a valve arm 49. With the valve arm 49 covering the fill opening 45 ("closed"), as shown in FIG. 3A, the coupling 15 will operate in the disengaged position. With the valve arm 49 uncovering the fill opening 45 ("open"), as shown in FIG. 3B, the coupling 15 will operate in the engaged condition. It should be noted that what is shown in FIGS. 3A and 3B is schematic, and is intended primarily to provide a definition of terms and a basis for understanding certain terms to be used hereinafter. Details of the valving of a preferred embodiment of the invention may be seen in the above incorporated U.S. Pat. No. 5,152,383. Referring again to FIG. 2, the rotary position of the armature 47 and valve arm 49 are controlled, by the actuator means 27, in response to changes in the input signal 29. The input signal 29 is transmitted to the actuator means 27 from the engine microprocessor 51, which may be of the type in commercial use as of the filing date of the present application. Associated with the vehicle engine E is an engine speed sensor 53 which transmits an engine speed signal SE as one input to the microprocessor 51. Associated with the radiator R is an engine coolant temperature sensor 55 which transmits a coolant temperature signal TC as another input to the microprocessor 51. Another input to the logic of the microprocessor 51 is a predetermined, nominal engine temperature setting TS, the function of which will be described subsequently. Those skilled in the art will understand that, although the temperature setting TS is illustrated by a potentiometer, the setting TS would typically be built into the software of the microprocessor 51, as a fixed input or setting. Finally, the vehicle includes an air conditioning system, one component of which is shown schematically in FIG. 2 as an air conditioning compressor AC. Associated with the compressor AC is a sensor 57 which is capable of transmitting a signal SC to the microprocessor 51, the signal SC preferably being capable of indicating either the request for air conditioning (i.e., status of the air conditioning ON or OFF switch), or the pressure of the refrigerant being pumped by the compressor AC. In either case, the signal SC indicates a need for operation of the viscous coupling 15 as a result of the operating state of the air conditioning system. Preferably, the actuator means 27 is of the type including a fan speed sensor 59 capable of transmitting a fan speed signal SF to the microprocessor 51. The fan speed signal SF measures actual speed of rotation of the fan F, whereas the input signal 29 to the actuator means 27 is generally representative of a demanded fan speed SD, as generated by the microprocessor 51. A fan speed sensor of the type which may be utilized in conjunction with the present invention is illustrated and described in U.S. Pat. No. 4,874,072, assigned to the assignee of the present invention and incorporated herein by reference. Preferably, the microprocessor 51 utilizes the various inputs to generate an appropriate input signal 29 (representative of "demanded" fan speed) in accordance with the teachings of U.S. Pat. No. 4,828,088, assigned to the assignee of the present invention and incorporated herein by reference. Referring now to FIG. 4, the microprocessor 51 receives the various inputs described above, and periodically executes the stop light idle logic. Although the term "idle" is used in reference to this logic, it is not so limited, but really refers to any relatively low engine speed condition. The logic begins with a first decision block 61 in which a "maximum possible demand" MPD is compared to the demanded fan speed signal SD. The maximum possible demand MPD is the highest possible fan speed which the system can demand, and which can be achieved. The determination of MPD must take into account certain factors, such as the pulley ratio between the engine E and the fluid coupling 15, as well as the "slip" speed within the coupling, i.e., the difference between input speed and output speed. If the maximum possible demand MPD is less than SD ("YES"), indicating that the engine speed SE has decreased suddenly, the logic proceeds to an operation block 62 in which the demanded fan speed SD (i.e., input signal 29) is set equal to the then current MPD. For example, if the demanded fan speed SD was 1500 rpm, but the engine speed SE suddenly drops to 1000 rpm, and the pulley ratio is 1.3:1, then the input speed to the fluid coupling 15 will drop to 1300 rpm. If the typical slip within the coupling, under those particular operating conditions, would be 100 rpm, then the maximum possible demand MPD would drop to 1200 rpm, and in the operation block 62, the demanded fan speed SD would be set to be equal to 1200 rpm. Regardless of the outcome of the decision block 61, the logic eventually proceeds to a decision block 63 in which the engine speed signal SE is compared to a lower limit L1 and to an upper limit L2. By way of example only, limit L1 may be 500 RPM and limit L2 may be 1000 RPM. If the engine speed is greater than L1 but less than L2 ("YES"), in other words, if the engine is stopped at a light and idling, or in some other low speed condition, the logic proceeds to the next decision block. If the engine speed SE is outside the limits ("NO"), the logic is exited, i.e., goes to "EXIT". If the engine is between L1 and L2, the logic proceeds to a decision block 65 in which the signal SC from the compressor AC is interrogated. If the signal SC indicates that the air conditioning system is operating, or that the compressor pressure is above a predetermined limit ("YES"), the logic proceeds to a decision block 67 in which the fan speed signal SF is compared to a signal which is representative of a demanded fan speed required to meet the cooling needs as a result of the operation of the air conditioning system, and specifically, the compressor AC. If the fan speed signal SF is not greater than the demanded fan speed which relates to the operation of the compressor ("NO"), the logic is exited. If the fan speed signal SF is greater than the demanded fan speed which relates to the operation of the compressor ("YES"), the logic proceeds to an operation block 69 in which the input signal 29 to the actuator means 27 is modified to move the valve arm 49 from the open position shown in FIG. 3B toward the closed position shown in FIG. 3A. Referring again to the decision block 65, if the air conditioning signal SC indicates that the air conditioning system is not operating, or that the compressor pressure is not above the predetermined limit ("NO"), the logic proceeds to a decision block 71 in which the actual fan speed signal SF is compared to a predetermined speed limit L3. By way of example only, the limit L3 could be about 700 RPM, and would indicate that the fan drive is operating at or near the engaged condition, thus suggesting the need to close the valve arm 49 before input speed to the fan drive increases. If the fan speed signal SF is greater than the limit L3 ("YES"), the logic proceeds to the operation block 69, with the result that the viscous coupling 15 is moved toward the disengaged condition. If the result of the decision block 71 is negative ("NO"), the logic proceeds to a decision block 72 in which the engine coolant temperature TC is compared to the predetermined temperature setting TS. If the temperature TC is less than the setting TS ("YES"), the logic also proceeds to the operation block 69, with the same result as described previously. If the result of the decision block 73 is negative ("NO"), the logic is exited. This particular logic block provides an "override" type of feature whereby, only if the coolant temperature TC rises above the predetermined temperature setting TS will the logic permit the viscous coupling 15 to continue to operate without moving the valve arm 49 toward the closed position (FIG. 3A). In other words, the fan drive speed may remain the same until the result of either of the decision blocks 65 or 71 is "YES". Referring now primarily to FIGS. 5 and 6, the microprocessor 51 periodically executes the slipheat protection logic. The logic begins at a first decision block 73 in which the engine speed signal SE is compared to a lower limit L1. It should be noted that the various limits L1, etc., identified in the logic of FIG. 5 would typically not have the same values as the limits referenced in the logic of FIG. 4, bearing the same references, and should not be confused therewith. Referring now to the graph of FIG. 6, there is illustrated a graph of fan speed (speed of the output coupling 31) versus input speed (speed of the input coupling 43). The purpose of the graph of FIG. 6 is to illustrate that, for any particular fan drive, there is a region of operation in which the particular fan speed and input speed would result in excessive slip horsepower, and therefore, excessive temperature buildup in the fan drive. In FIG. 6, there is a line labeled "CHP" representing the maximum allowable, constant slip horsepower. The coarsely shaded area generally to the left of the CHP line represents "safe" combinations of fan speed and input speed which will not result in excessive slip horsepower. The more finely shaded area, generally to the right of the CHP line and labeled "ESH" represents an area of operation beyond the recommended design limits, i.e., a combination of fan speed and input speed which will result in excess slip horsepower or excess slipheat. As was described in the BACKGROUND OF THE DISCLOSURE, operation in the excess slip heat region ESH means that the fluid coupling 15 will generate more slip heat than it can dissipate normally. Therefore, continued operation in the excess slip heat region can result in degradation of the viscous fluid. The above is all generally well understood by those skilled in the art. Referring still to FIGS. 5 and 6, the limit L1 to which the engine speed signal SE is compared in the decision block 73 represents the minimum input speed at which slip horsepower becomes a concern (or conversely, the maximum input speed which is certain to be "safe". In the subject embodiment, the lower limit L1 is about 2420 rpm. If the engine speed signal SE is not greater than the lower limit L1 ("NO"), the logic proceeds to an operation block 74 in which the logic is commanded to clear (or reset) a "flag", which serves the purpose of causing the logic to wait before going to "EXIT" and repeating the logic. If the engine speed signal SE is greater than the lower limit L1 ("ES"), the logic proceeds to a decision block 75 which merely queries the flag to be sure that it is clear. If it is not ("NO"), the logic proceeds to a decision block 77 in which the engine coolant temperature TC is compared to a temperature lower limit. If the temperature TC is less than the lower limit ("YES"), the logic would again proceed to the operation block 73 and clear the flag. By way of example only, the lower limit could be a value 5 degrees F lower than the temperature setting TS. If the temperature TC is not less than the lower limit ("NO"), the logic proceeds to an operation block 79 in which the input signal 29 to the actuator means 27 is modified to move the valve arm 49 from the closed position shown in FIG. 3A toward the open position shown in FIG. 3B, thus increasing the engagement of the fan drive 15. If the result of the query at the decision block 75 is that the flag is clear ("YES"), the logic proceeds to a decision block 81 in which the demanded fan speed is compared to a second speed limit L2, which is representative of the lower portion of the line CHP on FIG. 6. For example, if the input speed were 2600 rpm, the limit L2 would be about 1230 rpm. Reference is made herein, and in the appended claims, to the limit L2 being "determined", which can mean that the logic actually calculates L2, or can mean that the logic does a "look up" in a table, or consults a "map", or uses any other suitable method. If the demanded fan speed is not greater than the limit L2 ("NO"), the logic is exited, but if the demanded fan speed is greater than the limit L2 ("YES"), the logic proceeds to a decision block 83. In the decision block 83, the engine coolant temperature TC is compared to a temperature high limit. By way of example only, the high limit could be the temperature setting TS plus 5 degrees F. If the coolant temperature TC is not greater than the high limit ("NO"), the logic proceeds to an operation block 85, the function of which is to re-set the demanded fan speed SD to be equal to the lower part of the line CHP. In other words, the logic was asking for too much fan speed, and that demand is now being reduced, as long as the coolant temperature TC does not exceed the temperature high limit. After the operation block 85, the logic is exited. One function of the decision blocks 77 and 83 is to provide the system with some hysteresis, i.e., to prevent the fan drive from "cycling" between output speeds just below and just above the excess slip heat region ESH, such that, on the average, the fan drive would affectively be operating within the region ESH. In the decision block 83, if the temperature TC is greater than the temperature high limit ("YES"), the logic again proceeds to the operation block 79, as a result of which the fan drive is moved toward the engaged condition, represented by FIG. 3B. Also, in the operation block 79, the flag is "set", in preparation for the subsequent execution of the logic. After the operation block 79, the logic is exited. Referring again primarily to FIG. 6, it should be understood that the purpose of the logic is to recognize when the particular combination of input speed (i.e., engine speed signal SE) and fan speed (or demanded fan speed) would result in operation within the excess slipheat region ESH. Once such operation has been recognized, the function of the logic is to cause the fan drive to "jump over" the ESH region, and operate in the "safe" operation region above the ESH region. Preferably, this is accomplished by causing the valve arm 49 to move to the fully open position of FIG. 3B, thus causing the fan drive to operate in a fully engaged condition. For example, with an input speed of 2600 rpm, the logic would cause the fan drive to drive the fan F at a speed of about 2450 rpm, safely above the ESH region. Theoretically, it would be acceptable for the logic to cause the fan drive to operate on that portion of the line CHP which represents the "upper" limit of the region ESH. Therefore, at an input speed of 2600 rpm, the fan drive would be driven at just under 2200 rpm. However, it is preferable, partly to simplify the logic, and partly as a safety matter, to simply go to a fully engaged condition. The invention has been described in great detail in the foregoing specification, and it is believed that various alterations and modifications of the invention will become apparent to those skilled in the art from a reading and understanding of the specification. It is intended that all such alterations and modifications are included in the invention, insofar as they come within the scope of the appended claims.

A method of controlling a viscous fluid coupling (15) in which, when the vehicle engine (E) is operating at low speeds, if the speed of rotation (SF) of the fan exceeds a predetermined speed limit (L3), the input signal (29) to the coupling is modified to move the valve member (49) toward a closed position (FIG. 3A). This action reduces the occurrence of an overfill condition, thus reducing undesired fan noise when the engine again accelerates. Another aspect of the invention is to sense the speed (SE) of the engine, and whenever the sensed speed (SE) is high enough that operation in an excess slip heat region (ESH) is possible, compare the demanded fan speed (29) to the lower limit (CHP) of the slip heat region. Whenever the demanded fan speed exceeds the limit, the input signal (29) to the coupling is modified to operate the coupling at a speed safely above or below the slip heat region (ESH) depending on the state of control inputs such as engine temperature.

FIELD OF THE INVENTION The present invention relates to methods for suppressing dust from the surface of dust-producing bulk materials. More particularly, the present invention relates to methods for suppressing dust from the surface of coal and other such bulk materials. BACKGROUND OF THE INVENTION Undesired dust emissions are produced by coal and other bulk materials during their handling, storage, processing and utilization. Such dust emissions are considered to be a nuisance and, in the case of many of these bulk materials, can also constitute a health and safety hazard. As a result, dust from coal and other such bulk materials must be controlled within safe limits, which in many cases have been specified in federal, state or local legislation, Industrial and utility plants handling and storing coal and other bulk materials have therefore found it necessary to employ a variety of control technologies in order to reduce the potential health and safety hazards posed by such dust emissions, as well as to comply with applicable legislation. These dust control technologies can be separated into the general categories of mechanical and chemical technologies. In the case of mechanical techniques, devices such as fabric filters and cyclones have been used to collect and dispose of such dust emissions. While mechanical controls can be very efficient, they do often require a large capital expenditure, and they are not always applicable to all of the unit operations that can produce dust in a typical handling and storage system. Chemical controls, on the other hand, employ additives which are generally applied to the material as a liquid spray or foam. The most common such additive for dust control is water, which is generally applied during the unloading, crushing, or conveying operations. Water, while it is useful in suppressing dust at the point of application, quickly evaporates, thus rendering the material dusty again and, in the case of coal, also detracts from its calorific value. Various oils have also been used for dust suppression, but they are not as widely used today, primarily since they are often contaminated with toxic substances and/or because they pose a hazard to local water supplies. In Severn, U.S. Pat. No. 908,041, for example, the use of heavy mineral oil, along with sand belt dust, is disclosed for collecting and holding dust particles. In the last two decades, a wide variety of chemical agents have been developed for the specific purpose of improving upon the performance of water and oil sprays. The most common additives to water for such purposes have been wetting agents, that is surfactants, which improve the ability of the water to wet and spread onto the particulate material. These surfactants are thus usually added in low concentrations, and can be quite effective in improving the performance of these water sprays on difficult to wet materials, such as coal. To a lesser extent, emulsifying agents and similar substances can also be added to oils to improve their effectiveness. Foaming agents described, for example, by Salyer et al in U.S. Pat. No. 3,954,662, in this case being aqueous solutions of an interpolymer of a vinyl ester and certain partial ester compounds, have improved upon wetting agent technology, and are now widely used in several bulk material handling systems. These foaming agents are dissolved in water, and compressed or aspirated air is then used to produce a low or high expansion foam for application to the bulk material. The use of such foams permits a reduction in water consumption as compared to conventional spray systems, and is generally regarded as more effective in capturing finer particulate materials. They are, however, considerably more expensive than water or surfactant solutions. While both water and water solutions of wetting or foaming agents are generally effective in reducing dust at the point of their application, they are unable to control dust emissions from downstream unit operations. This is particularly true during outdoor storage. A utility power plant may, for example, spray the coal with these solutions when it is unloaded from trains in order to reduce dusting during this operation. The coal, however, must then be conveyed to large outdoor stockpiles, where it remains until it is reclaimed for combustion. The length of time in such storage may vary from a few days to several months, and during this period dust emissions are produced by both wind erosion and by the movement of equipment on the piles. In such cases, conventional water sprays or treatments with wetting agents or foams do not persist in performing their described function during such storage, primarily because they evaporate, are absorbed, or are present in concentrations which are far too low to sustain weathering. As a result, it often becomes necessary to treat such storage piles with coatings or encrusting agents so as to reduce emissions created by wind erosion and the like. For such purposes, latex emulsions are commonly employed as coating agents, as have a wide variety of other substances, such as lignosulfonates, asphalts, waxes, and numerous polymers. However, these agents are only useful as encrusting agents on the surfaces of inactive piles. Once such coatings are disrupted by reclamation operations or vehicular traffic, the effectiveness of such coatings is destroyed. Sherman, in U.S. Pat. No. 4,383,971, teaches that the surface of a coal stockpile may be protected by covering the pile with straw, and then spraying a coating of asphalt emulsion on top of the straw to prevent it from blowing away. The surface can then be seeded with grass, which will grow to completely cover the surface and provide a high degree of protection. Obviously, however, such a solution is useful only for coal in "dead" storage, where the pile may remain inactive for a period of years. Thus, said pile coatings are of limited usefulness on active piles, where the surface is worked by machinery, etc. On piles with active surfaces, only the sloped perimeters where there is little traffic can be adequately protected by such a coating. Consequently, a typical bulk material handling facility may employ several different dust control technologies in order to reduce emissions from the combination of various unit operations that make up their handling systems. The cumulative costs of such separate systems for the purpose of reducing dust emissions during unloading, conveying, stack-out to piles, storage, pile reclamation, crushing, etc. can thus be rather excessive. In order to reduce these substantial dust control costs, so-called "residual" dust suppressants have thus been developed for the purpose of controlling emissions throughout a series of unit operations. These products are typically combinations of solutions of surfactants and foaming agents with other ingredients that can bind the dust particles together even when the moisture evaporates. Salihar, U.S. Pat. No. 4,551,261, describes, for example, a combination of foaming agent and a latex comprising an elastomeric water-miscible polymer. When this material is sprayed as a foam it is effective in reducing dust at the point of application. Furthermore, after the moisture has evaporated, the latex dries to a film which binds particulate together and prevents wind erosion during storage. Another example of such a residual dust suppressant is provided by Kittle, U.S. Pat. No. 4,561,905, which describes an oil in water emulsion applied as a foam. Other residual dust suppressants incorporating lignosulfonates, various polymers, starches, and oils are also sold commercially as residual dust suppressants. Since the residual dust suppressant is applied to all of the material entering a particular pile, the product can thus continue to reduce emissions, and this can be true even though the pile may be very active. The residual dust suppressants thus combine water spray and coating formulations into products that are effective throughout a series of unit operations. While the advent of residual dust suppressants has therefore been of assistance in reducing the number and types of dust control systems used in bulk material handling, they are generally quite expensive. The costs of these materials may thus range between 5 and 40 cents per ton treated, depending upon the moisture, size, and composition of the material. Furthermore, the EPA has pointed out that chemical dust suppressants are often by-products or waste materials. Some of these dust suppressants have thus been found to contain heavy metals and PCB's, and the EPA suggests that the user should analyze the dust suppressant for toxic substances, and also test for possible reactivity between the suppressant and the substrate material itself. It therefore does not appear that ay of this prior art describes the use of cellulosic fibers as a dust suppressant. Strips of Kraft paper have been used to separate layers of coal in piles to prevent oxidation, such as in Brown, U.S. Pat. No. 2,251,321. Furthermore, sawdust has been incorporated into dust absorbing compositions to facilitate floor sweeping, as described in Wolfram, U.S. Pat. No. 892,484. In these cases, however, neither pertains to the problems of dust production during the handling and storage of bulk materials, such as coal. SUMMARY OF THE INVENTION In accordance with the present invention, these and other objects have now been realized by applicant's invention of a method for suppressing dust from the surface of dust-producing bulk materials which includes preparing an aqueous composition including cellulosic fibers dispersed in water and applying that aqueous composition to the surface of the dust-producing bulk material in order to suppress generation of dust from that surface. In accordance with a preferred embodiment of the method of the present invention, the aqueous composition includes between about 0.1 and 20 wt. % of these cellulosic fibers therein, preferably between about 0.1 and 10 wt. %, and most preferably between about 0.5 and 5 wt. %. In accordance with another embodiment of the method of the present invention, the method includes preparing the aqueous composition by including polymeric emulsions or solutions therein. In accordance with another embodiment of the method of the present invention, the cellulosic fibers are produced by the mechanical or chemical processing of wood pulp. In another embodiment, the cellulosic fibers are produced by the repulping of paper, such as newsprint. In its most preferred form, the present method includes suppressing dust from the surface of coal. The method of the present invention can include applying the aqueous composition to the material such as coal in bulk, so as to prevent the generation of dust during handling, or alternatively as a coating to protect entire storage piles of such materials from wind erosion and the like. Furthermore, other known dust suppressants can be included along with the aqueous compositions of the present invention in order to improve their performance and/or lower the cost thereof. It has thus been discovered that, in a particularly preferred embodiment thereof, cellulosic fibers such as mechanical or chemical fiber pulps can control dust emissions from bulk materials over prolonged periods of time. These pulps consist of suspensions of cellulosic fibers in water. When applied to a bulk material like coal, these fibers tend to bind and aggregate fine dust particles together as the moisture evaporates therefrom. These pulps can thus be used as (1) a residual dust suppressant, (2) a pile coating, and (3) as an additive with other dust suppresants. DETAILED DESCRIPTION The fiber pulps useful as dust suppressants in accordance with this invention can comprise such pulps which are the product of either mechanical or chemical pulping methods. In the mechanical pulping methods, mechanical pulpers or refiners grind wood chips to liberate cellulosic fibers into an aqueous suspension. In chemical pulping methods, of which the Kraft process is the most widely used, solutions of chemicals, like sodium sulfate or sulfite, are employed for the purpose of digesting the wood. Pulps which are useful as the source of cellulosic fibers in accordance with this invention may also be manufactured by repulping paper. Mechanical digesters are thus used to grind newspring or other grades of paper into the pulps from which they were originally made. This process has a very low energy requirement, and also permits the recycling of what would otherwise be waste. For this reason, pulps prepared from newsprint or other waste paper are particularly useful for the purposes of this invention. Many bulk material handling facilities are close to metropolitan areas, where abundant and low-cost supplies of waste paper and newsprint are available. For papermaking, raw mechanical or chemical pulps are washed, bleached, or de-inked. For the purpose of this invention, the pulps employed as dust suppressants do not have to meet rigorous standards of purity, and cleaning or bleaching can thus be eliminated in order to lower the cost thereof. Pulps useful in this invention can be prepared with solids contents up to as much as 20% by weight, i.e., from about 0.1 up to about 20 wt. %. Such concentrated pulps are, however, difficult to pump and spray. Consequently, pulps with solids contents ranging from about 0.1 to 10.0 wt. %, and more preferably from about 0.5 to 5.0 wt. % are preferably used as such dust suppressants. The use of pulp as a dust suppressant offers several additional advantages. Firstly, the raw materials for manufacturing the pulp are extremely inexpensive and readily available, particularly as compared to ingredients which have been used for chemical dust suppressants. Secondly, pulps manufactured from wastepaper and newsprint thus result in the recycle of a material that would otherwise pollute, and which would require some other method of disposal. Thirdly, pulps are environmentally safe and biodegradable. Finally, pulps can be manufactured with readily available and simple equipment. Examples of experimental results demonstrating that pulps are effective as a residual dust suppressant, encrusting agent and active filler now follow: EXAMPLE 1 This example demonstrates that pulp is useful as a residual dust suppressant. In this case, three specimens of a bituminuous coal screened to contain only particles of less than 1/4 inch were prepared. Each of these three specimens weighed 0.900 Kg. The first coal specimen was not treated, and was thus used to establish a baseline of fugitive dust emission concentrations. The second sample was treated with 1.0 wt. % of a mechanical pulp having a solids content of 5%. The third specimen was treated with 3 wt. % of a pulp having a solids content of 1.67%. While treated specimens contained different amounts of water, the amount of fiber applied to each was the same, i.e. 0.05 wt. %. This corresponds to approximately 1 lb. of fiber per ton of material. These treated and control specimens were then subjected to dust box tests using a method described in ASTM D547-41, "Standard Test Method for Determining the Dustiness of Coal and Coke." Specimens were dropped into a sealed container, and the impact with the base of the container produced a cloud of dust. The concentration of dust was measured and used to compare treated and control specimens. The coal specimens were subjected to dust box tests immediately after their preparation, and also at intervals of 1, 2, 3, 4, 6, 12, and 29 days. During this period the specimens were allowed to stand in air to simulate the drying that occurs on a pile surface. Dust emissions from each sample were recorded over this entire period in order to determine the residual effectiveness of each treatment by measuring percent suppression as a function of time. Percent suppression was calculated at each test interval using the equation: ##EQU1## where D c =Dust concentration measured for control, and D s =Dust concentration measured for treatment specimens. The control specimen was initially at an equilibrium moisture content of 5.5%. The treated specimens were prepared at moisture contents of 6.5% and 8.5%, respectively. As the samples dried they became dustier. After four days the surface moisture of the control had dropped to 0.91%, while the surface moistures of the treated specimens had declined to 0.86% and 0.66%, respectively. After 29 days all of the specimens had dried to 0% surface moisture. In this fashion, the interfering effects of surface moisture were eliminated, and any reduction in dust emissions was due solely to the presence of the pulp fibers. Table I lists the results of tests by tabulating percent suppression as a function of time. TABLE I__________________________________________________________________________Results of Coal Dustiness Tests Percent Suppression Calculated on Day:SampleTreatment 0 1 2 3 4 6 13 29__________________________________________________________________________1 None -- -- -- -- -- -- -- --2 1% of 5% pulp -- -- 97.1 93.8 70.6 83.9 64.7 48.53 3% of 1.7% pulp -- -- 100 94.7 79.7 71.6 78.0 54.2__________________________________________________________________________ Linear regression was used to express percent suppression as a function of time for treated samples 2 and 3. This produced the following equations, in the form y=mx+b; for sample 2, %S=-1.28t+88.9% for sample 3, %S=-1.33t+93.1% where t=rate at which percent suppression decreases with time, expressed as %/day. Dividing the intercept, b, by the slope, m, thus permitted calculation of the amount of time required for percent suppression to decrease to 0%. For sample 1, this figure was 69 days, and for sample 2, 70 days. From these test results it was concluded that pulp fibers are effective residual dust suppressants which persist in activity up to 70 days, at least under the conditions of this experiment. It was also concluded that the amount of water added with the pulp was not critical, so long as there was sufficient liquid to adequately distribute the fibers. EXAMPLE 2 This example demonstrates that pulp is an effective dust suppressant coating for stockpiles of bulk material. Two 150 lb. samples of coal were placed into test bins measuring 24"L×26"W×10"H, and their surfaces were mounded into a roughly conical shape. The surface of one sample was coated with a 5% pulp, corresponding to a treatment rate of 3.3 gallons per 1000 ft 2 . The surface of the second sample was not coated. Both piles of coal were placed outdoors and allowed to weather for a period of 30 days. During this period, both test piles were subjected to the same conditions of wind and rain erosion. Visual examination of the coated surface revealed that pulp fibers had dried to form a crust on the surface, which persisted throughout the test. After 30 days, a size distribution analysis was conducted on surface samples from each pile. The coal used in each bind and originated from the same homogeneous master sample. Therefore, any decline in the amount of fine material at the surface after 30 days was indicative of the amount of wind and rain erosion. Wind erosion washes it down to the base of the pile. Table II shows the results of size distribution analyses performed on specimens taken from the top 1/4" of the surface TABLE II______________________________________Size Distribution Analyses Initial Size Size Distribution after 30 DaysU.S. Standard Distribution Untreated Surface Coated withSieve Size (wt. %) (wt. %) Pulp (wt. %)______________________________________ + 1.4 16.1 13.4 3.5-1.4 + 5 12.2 18.3 13.2-5 + 10 19.7 36.6 30.5-10 + 30 25.4 22.6 28.5Total + 30 73.4% 90.9% 75.7%-30 + 60 14.6 3.8 10.0-60 + 100 4.7 1.5 4.3-100 + 200 4.1 1.3 3.7-200 3.2 2.3 6.1Total - 30 26.6% 8.9% 24.1%______________________________________ In accordance with these test results, the untreated pile surface showed a pronounced decrease in fine particulate after 30 days of outdoor storage. The weight percent of particles below 30 mesh (about 1 mm.) declined from 26.6% to only 8.9% as a result of wind and rain erosion. No similar or significant change was observed for the test pile coated with pulp in accordance with this invention. Treated and untreated pile surfaces were also vacuumed to determine whether less fine material would be swept from the coated surface. A 5 mesh screen of 7.75" in diameter was placed onto the surface of each pile, and a small vacuum cleaner was used to sweep coal through the screen for one minute. The amount of dust was collected and weighed. Table III lists the results of the test. TABLE III______________________________________Surface Vacuuming Test Results Amount of DustSample Test No. Treatment Collected (gm)______________________________________1 1 Untreated 1.7 2 Untreated 1.5 Average 1.62 1 Coated with 5% pulp 0.4 2 Coated with 5% pulp 0.7 Average 0.55______________________________________ These results demonstrate that 65% less particulate was vacuumed from the coal pile surface coated with an aqueous suspension of pulp fibers. The coating was also observed to retain its integrity over the thirty day test period. The fibrous mat intertwining fine coal particles could be lifted from the surface of the pile as a demonstration of the protection afforded the surface against wind and rain erosion. EXAMPLE 3 This example demonstrated that pulp is also useful as an additive to other encrusting formulations. Latex is a common film-forming agent that has been used to coat stockpile surfaces as a means of protection against the elements. Varying percentages of pulp fiber were thus added to a common latex being sold as a dust suppressant, and the resulting mixtures were cast into thin films. The films of each composition were removed from the substrate and cut into strips 2 inches long and 1/4" wide. These strips were then tested in tension to determine the force required to break them. In this fashion it could be determined whether the addition of pulp fibers contributed to strengthening the film. Test data is tabulated in Table IV. TABLE IV__________________________________________________________________________Strengths of Latex Films Containing Pulp Fibers Composition Latex Pulp Fiber TensileNo. of (40% solids) (5% solids) Water Content StrengthSampleTests gms. gms. gms. % gm/mm.sup.2__________________________________________________________________________1 7 20 180 0 4.50 1145 ± 1472 9 20 90 90 2.25 4627 ± 10523 9 20 9 171 0.23 1939 ± 5754 3 20 0.9 179.1 0.02 1304 ± 5025 3 20 0 180 0.0 1088 + 47__________________________________________________________________________ These results demonstrate that as the amount of fiber in the film increased, the tension strength rose to a maximum, and then declined. Over the range of from 0 to 4.5% fiber content all values of tensile strength are well above that of the latex film alone. Even as little as 0.02% fiber increased the film strength by 19.8%. The addition of 2.25% fiber to the formulation increased the tensile strength by a factor of 4.25. One would intuitively expect to see a similar increase in tensile strength with other coating agents where the pulp fibers are able to reinforce a polymeric film. It should also be appreciated that cellulosic fibers can be used to reinforce and improve other film-forming and adhesive dust suppressants in addition to latex emulsions. These can include, for example, asphalt emulsions, lignosulfonates, molasses, and other such polymeric materials that are water soluble or dispersable. Latex was selected for use in the above example because it is the most commercial significant pile coating agent. In summary, the experimental data of examples 1, 2, and 3 show that (1) pulps can significantly reduce the dusting of coal and other materials when applied in an amount approximating 1 pound of fiber per ton, (2) pulps applied to the surfaces of stockpiles reduce wind and rain erosion, and (3) pulps can be used as a reinforcing filler in other dusts suppressant formulations. The present invention can therefore offer several advantages as a dust suppressant. Firstly, pulps are very inexpensive as compated to dust suppressant products formulated with specialty chemicals, and therefore the costs to the end-user will decrease thus providing a stronger incentive to control fugitive dust emissions. Secondly, pulps useful as dust suppressants can be manufactured from waste products, such as newsprint, and recycled materials that would require less desirable methods of disposal. Thirdly, pulp fibers are combustible or biodegradable, and as such their use is environmentally compatible. Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

Methods for suppressing dust from the surface of dust-producing bulk materials such as coal are disclosed including preparing an aqueous suspension of cellulosic fibers dispersed in water and applying the aqueous suspension to the surface of the dust-producing bulk materials in order to suppress dust formation from that surface. The method can comprise use of the cellulosic fiber suspensions as a residual dust suppressant, as a dust suppressant coating for stockpiles of these bulk materials, or as an additive with other encrusting formulations such as latex.

RELATED APPLICATIONS [0001] This application is based on German Patent Application 10 2008 014 462.2 filed Mar. 14, 2008, upon which priority is claimed. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates to a hydraulic vehicle brake system. [0004] 2. Description of the Prior Art [0005] Such vehicle brake systems are conventional per se in motor vehicles. They have a master cylinder, which is actuated by muscle force by a vehicle driver by means of a brake pedal, or in the case of a motorcycle, by means of a manual brake lever. Wheel brake cylinders are connected hydraulically to the master cylinder. For antilock vehicle brake systems, brake pressure buildup valves and brake pressure reduction valves for modulating the brake pressure are disposed between the master cylinder and the wheel brake cylinders; for individual-wheel brake pressure modulation, one brake pressure buildup valve and one brake pressure reduction valve are disposed respectively upstream and downstream of each wheel brake cylinder. In simplified regulating systems, one brake pressure buildup valve and one brake pressure reduction valve can for instance be provided for the wheel brakes of one axle as well. Moreover, typically in each brake circuit is one hydraulic pump as a return pump and/or for pressure buildup, and a hydraulic reservoir as well as further hydraulic valves are provided. Such brake pressure regulating systems are known per se to one skilled in the art and will not be described further here, since they do not form the actual subject of the invention. [0006] In motor vehicles, underpressure brake boosters are typical, for enhancing the muscle force of the diver of the vehicle. Electrohydraulic brake boosters and external-force brake systems are also known, in both of which an external power supply to the vehicle brake system is accomplished with a hydraulic pump that is driven by an electric motor. Temporary storage of brake fluid under pressure in a hydraulic reservoir is typical. In the event of brake boosting, or in other words a so-called auxiliary force brake system, the brake pressure generated by the driver by muscle force by actuation of the master cylinder is enhanced with the external power supply; in the case of an external force brake system, the pressure buildup is effected solely with the external power supply; the master cylinder is disconnected hydraulically from the rest of the vehicle brake system. Only upon auxiliary braking, or in other words emergency braking in the event of failure of the external power supply is the actuation effected by muscle force using the master cylinder. OBJECT AND SUMMARY OF THE INVENTION [0007] The hydraulic vehicle brake system of the invention takes a different course: Like conventional hydraulic vehicle brake systems, it has a master cylinder, to which the vehicle brake system is hydraulically connected and with which it is actuated by muscle force by the vehicle driver. The hydraulic vehicle brake system of the invention furthermore has an electrohydraulic pedal travel modulator that has a piston-cylinder unit which communicates with the master cylinder and which has an electromechanical drive. By actuation of the piston-cylinder unit of the pedal travel modulator, brake fluid is positively displaced from the piston-cylinder unit and reaches the master cylinder and the vehicle brake system. As a result, an actuation travel required for a brake actuation, that is, a displacement of a piston of the master cylinder, is shortened. Via the brake pedal, brake lever, or other user control element, the vehicle driver executes only a portion of the actuation travel and thus positively displaces a defined volume of brake fluid from the master cylinder into the vehicle brake system. A further volume of brake fluid is furnished by the pedal travel modulator. No force boosting takes place; the pressure in the master cylinder and in the wheel brakes is not increased by the pedal travel modulator. [0008] The displacement of the piston in the cylinder of the piston-cylinder unit of the pedal travel modulator, or in other words the volume of brake fluid that is positively displaced from the piston-cylinder unit and delivered to the vehicle brake system, is controlled or regulated as a function of a travel of the brake pedal, that is, as a function of a displacement of the piston of the master cylinder. The term “brake pedal” is understood in general also to mean a manual brake lever or other user control element for displacing the piston of the master cylinder. The pedal travel modulator can be said to effect a travel boost of the brake pedal, or in other words it increases the volume of brake fluid positively displaced, without enhancing the requisite muscle force. The dependency may, but need not, be linear, so that with the pedal travel modulator of the invention, as a further advantage, an intrinsically arbitrary pedal characteristic can be attained, the term “pedal characteristic” being understood to mean the dependency of the pedal travel on the pedal force. Force boosting can be attained by the hydraulic boosting of the master cylinder to the wheel brakes, in that the bore and piston diameter of the master cylinder is reduced and/or the piston diameter of the wheel brake cylinder is increased. An underpressure booster or other brake force booster can be dispensed with and according to the invention is not provided. In the event of a failure of the pedal travel modulator, auxiliary braking is possible solely by muscle force, and the pedal force is not increased by the failure of the pedal travel modulator; only the pedal travel increases. [0009] The drive of the piston-cylinder unit of the pedal travel modulator can be effected for instance with a linear motor, an electromagnet, or a piezoelectric element. An electromechanical drive with an electric motor and a mechanical gear is provided, which converts the rotary driving motion of the electric motor into a translational motion for displacing the piston in the cylinder of the piston-cylinder unit and which preferably includes a step-down gear. Since the invention makes a hydraulic force boosting from the pedal travel modulator to the master cylinder or the wheel brake cylinders possible, the invention makes do with a comparatively slight mechanical speed reduction, or even entirely without a step-down gear. [0010] At least one self-boosting wheel brake is provided in the vehicle brake system of the invention. Preferably, the brakes of one axle are structurally identical; that is, they are either self-boosting or non-self-boosting, or all the wheel brakes can be self-boosting. Both hydraulic and mechanical self-boosting devices are known, which need not be described further here. For mechanical self-boosting devices, wedge or ramp mechanisms are known, on which a friction brake lining of a disk brake is braced displaceably in the circumferential direction of the brake disk. The rotating brake disk urges the friction brake lining into an increasingly narrower wedge gap between the oblique wedge or ramp face and the brake disk, and by the principle of the wedge, brake boosting ensues. A travel-boosting self-boosting device is provided, in which the force is not boosted, but instead the travel, or in other words the positioning motion of the friction brake lining to the brake disk, is increased. For that purpose, the wedge or ramp mechanism is braced on the piston of the hydraulic wheel brake, so that the contact pressure of the friction brake lining against the brake disk is equal in magnitude to the tensing force generated by the brake piston. The bracing of the friction brake lining at an angle obliquely to the brake disk effects a positioning motion of the friction brake lining, or in other words a travel boost. This is known per se to one skilled in the art and therefore, and because the structural design of the self-boosting device of the wheel brake or brakes does not form the actual subject of the invention, will not be described in further detail here. The self-boosting devices are not limited to the structural types claimed. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings, in which: [0012] FIG. 1 is a schematic illustration of a vehicle brake system according to the invention; and [0013] FIG. 1 a shows an alternative detail. DESCRIPTION OF THE PREFERRED EMBODIMENT [0014] The vehicle brake system according to the invention, shown in FIG. 1 and identified overall by reference numeral 1 , has a dual-circuit master cylinder 2 , to which wheel brakes 4 are connected via a hydraulic anti-lock and traction control unit 3 . The traction control unit 3 is of a design known per se; for example, the ESP System 8.0 of the Applicant can be used, which makes individual-brake pressure regulation possible. Such anti-lock and traction control systems are known to one skilled in the art, so that they need not be explained here. [0015] The master cylinder 2 and with it the vehicle brake system 1 are actuated by muscle force, using a brake pedal 5 . In the case of a hand brake, a brake lever, instead of the brake pedal 5 , would be provided as a user control element. With a travel sensor 6 , a pedal travel of the brake pedal 5 or a piston travel of a rod piston 7 of the master cylinder 2 , which piston is connected mechanically to the brake pedal 5 via a piston rod 8 , is measured. A pressure sensor 9 is connected to one of the two brake circuits of the vehicle brake system 1 . [0016] An actuation of the vehicle brake system 1 is effected in the usual way by pressing down on the brake pedal 5 , or in other words by actuating the master cylinder 2 , from which brake fluid is positively displaced as a result; the brake fluid builds up a brake pressure in cylinders of the wheel brakes 4 , which communicate with the master cylinder 2 . Individual-wheel brake pressure regulation in the brake cylinders of the wheel brakes 4 is effected as needed automatically, with the hydraulic anti-lock and traction control unit 3 . [0017] One circuit of the master cylinder 2 , which in the exemplary embodiment is the rod circuit, communicates with a piston-cylinder unit 10 of a pedal travel modulator 11 . The piston-cylinder unit 10 of the pedal travel modulator 11 has a cylinder 12 , in which a modulator piston 13 is displaceable. The pedal travel modulator 11 has an electromechanical drive 14 , with an electric motor 15 that displaces the modulator piston 13 in the cylinder 12 via a gear wheel step-down gear 16 and a rack gear 17 . A piston rod 18 of the modulator piston 13 has a rack 19 , which is part of the rack gear 17 . [0018] Driving the modulator piston 13 causes brake fluid to be positively displaced out of the cylinder 12 of the piston-cylinder unit 10 of the pedal travel modulator 11 into the rod circuit of the master cylinder 2 or the vehicle brake system 1 . The hydraulic pressure is not increased as a result; it is determined solely by the muscle force exerted on the brake pedal 5 , which force acts on the rod piston 7 of the master cylinder 2 . However, the volume of brake fluid made available by the pedal travel modulator 11 shortens the pedal travel required for building up a defined brake force; that is, by means of the pedal travel modulator 11 , a kind of hydraulic travel boosting is effected. As a result, a greater hydraulic force boosting is possible by means of a smaller diameter of the pistons of the master cylinder 2 in proportion to the pistons in the cylinders of the wheel brakes 4 , and as a result, in turn, a brake booster, such as an underpressure brake booster, can be dispensed with. [0019] The pedal travel modulator 11 is controlled or regulated as a function of the pedal travel of the brake pedal 5 ; this travel is measured by the travel sensor 6 . The control or regulation of the pedal travel modulator 11 is effected with an electronic control unit, not shown, which preferably simultaneously controls the hydraulic anti-lock and traction control unit 3 , or in other words the ESP unit, as well. In other words, the control or regulation of the pedal travel modulator 11 can be integrated with the control unit, which is present anyway, of the hydraulic anti-lock and traction control unit 3 . The control or regulation of the pedal travel modulator 11 can be effected with a linear or other kind of fundamentally arbitrary dependency on the pedal travel. The pedal travel modulator 11 has a travel sensor 20 for measuring the displacement of the modulator piston 13 . As a result, an intrinsically arbitrary pedal characteristic can be achieved, the term pedal characteristic meaning the dependency of the pedal travel of the brake pedal 5 on the muscle force exerted on the brake pedal 5 . [0020] In the event of failure of the pedal travel modulator 11 , braking is effected solely by muscle force in the usual way, by pressing down on the brake pedal 5 . Since the pedal travel modulator 11 does not cause any force boosting but only travel boosting, the actuation force required for actuating the vehicle brake system 1 , that is, the muscle force to be exerted on the brake pedal 5 , is not increased; only the pedal travel is lengthened. The modulator piston 13 has a piston reverse-stroke limiter, which defines its basic position when the vehicle brake system 1 is not actuated but instead is released. In the exemplary embodiment, a spring ring 21 , as a piston reverse-stroke limiter 21 , is inserted into a groove of the cylinder 12 of the piston-cylinder unit of the pedal travel modulator 11 . The piston reverse-stroke limiter, in the event of failure of the pedal travel modulator 11 , prevents brake fluid upon brake actuation from being positively displaced out of the master cylinder 2 into the cylinder 12 of the piston-cylinder unit 10 of the pedal travel modulator 11 . In the event of failure of the pedal travel modulator 11 , the brake fluid positively displaced from the master cylinder 2 upon actuation is entirely available for the actuation of the wheel brakes 4 , and no brake fluid is “lost” into the cylinder 12 of the piston-cylinder unit 10 of the pedal travel modulator 11 . The piston reverse-stroke limiter 21 defines a basic position of the modulator piston 13 when the vehicle brake system is not actuated; displacement from the basic position and an alteration of the pedal characteristic are prevented. [0021] Since the pedal travel modulator 11 acts on only one of the two brake circuits of the vehicle brake system 1 , the hydraulic disconnection of the two brake circuits remains assured. [0022] A valve 22 is disposed between the piston-cylinder unit 10 of the pedal travel modulator 11 and the master cylinder 2 , or the vehicle brake system 1 . In the exemplary embodiment, this is a 2/2-way magnet valve, which in its currentless basic position connects the piston-cylinder unit 10 to the master cylinder 2 and the vehicle brake system 1 by means of a throttle restriction 23 . In a switching position when current is being supplied, the valve 22 is open; that is, it connects the piston-cylinder unit 10 of the pedal travel modulator 11 to the master cylinder 2 and to the vehicle brake system 1 . In normal operation, current is supplied to the valve 22 ; that is, it is open, and its opening is effected for instance with the activation of an ignition of a motor vehicle. In the event of an electrical failure or of the pedal travel modulator 11 , the valve 22 switches over to the currentless basic position. If the failure takes place during braking with the master cylinder 2 actuated, the throttle restriction 23 of the valve 22 throttles the flow of brake fluid from the master cylinder 2 into the cylinder 12 of the piston-cylinder unit 10 of the pedal travel modulator 11 , so that the brake pedal 5 does not “collapse” but instead yields slowly and spares the vehicle driver from the shock of sensing a total failure of the vehicle brake system 1 . The failure of the pedal travel modulator 11 can be ascertained from the lack of motion of the modulator piston 13 that is measured with the travel sensor 20 . Since the valve 22 is switched over quite infrequently, namely when the ignition is switched on and off, it has a very long service life. [0023] As an alternative, the valve 22 ′ shown in FIG. 1 a can be provided instead of the valve 22 . It is a 2/2-way magnet valve, which is open in its currentless basic position and closed in its switching position when current is being supplied. By closure of the valve 22 ′, the piston-cylinder unit 10 is disconnected hydraulically from the master cylinder 2 and the vehicle brake system 1 , so that a supply of current to the electric motor 15 can be switched off when the vehicle brake system is actuated during braking. In braking events that are long-lasting, the electric motor 15 can thereby be thermally relieved. [0024] In a preferred embodiment of the invention, some of the wheel brakes 4 , or all the wheel brakes 4 , are self-boosting. Preferably, the wheel brakes 4 of one or more or all the vehicle axles are self-boosting; because of the greater braking power, the wheel brakes 4 of a front axle are preferably self-boosting. In the drawing, the self-boosting of the two wheel brakes 4 shown on the left is represented by the symbol for a wedge mechanism 24 . Self-boosting wheel brakes are known to one skilled in the art, so that further explanation is unnecessary. Other known kinds of brakes include hydraulic and mechanical self-boosting devices, the latter in particular having wedge or ramp mechanisms that brace a friction brake lining, which is displaceable in the circumferential direction of a brake disk, obliquely to the brake disk. For the invention, travel-boosting wheel brakes 4 are preferred, in which some of the positioning travel of the friction brake linings toward the brake disk is effected by the displacement of the friction brake lining in the direction of rotation of the brake disk with the wheel brake 4 actuated, because of the oblique bracing in the brake caliper with the wedge or ramp mechanism. As a result, the volume of brake fluid, which must be positively displaced from the master cylinder 2 , that is required for brake actuation is reduced; the requisite pedal travel is shortened. The pedal travel shortening also results if even only some of the wheel brakes 4 are self-boosting (travel-boosting); it is not necessary for all the wheel brakes 4 to be self-boosting. Via the floating piston 25 of the master cylinder 2 , the travel boost also acts on the respective other brake circuit of the vehicle brake system 1 . [0025] A small diameter of the modulator piston 13 results in great travel reduction and great force boosting, as a result of which a slight travel reduction of the mechanical gear wheel gear 16 is possible, under some circumstances even an omission of the gear wheel gear 16 and a direct drive of the piston rod 18 via the gear rack drive 17 with the electric motor 15 . [0026] The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.

The invention proposes equipping a hydraulic vehicle brake system with a pedal travel modulator that has an electromechanically driven piston-cylinder unit. The piston-cylinder unit upon brake actuation “furnishes” additional brake fluid and thereby boosts a pedal travel of the vehicle brake system.

FIELD OF THE INVENTION The present invention relates to video compression generally and, more particularly, to a method and/or architecture for efficiently implementing a MPEG-4 AVC deblocking filter on an array of parallel processors. BACKGROUND OF THE INVENTION Referring to FIG. 1 , a diagram is shown illustrating divisions of a video frame 10 in accordance with the MPEG-4 part 10 advanced video coding (AVC) standard. The MPEG-4 part 10 standard defines a method for video compression that operates on rectangular groups of pixels. The type of compression performed by the MPEG-4 part 10 AVC standard is generally referred to as “block-based” compression. Each frame 10 of video is divided into a number of macroblocks 12 . Each of the macroblocks 12 is further divided into transform blocks 14 . The transform blocks 14 can also be referred to as sub-blocks. As part of the video compression process, a prediction for the pixels in each macroblock 12 is generated based upon either (i) pixels from adjacent macroblocks 12 in the same frame 10 or (ii) pixels from previous frames in the video sequence. Differences between the prediction and the actual pixel values for the macroblock 12 are referred to as residual values (or just residuals). The residual values for each transform block 14 are converted from spatial-domain to frequency-domain coefficients. The frequency-domain coefficients are then divided down to reduce the range of values needed to represent the frequency-domain coefficients through a process known as quantization. Quantization allows much higher compression ratios, but at the cost of discarding information about the original video sequence. Once the data has been quantized, the frames of the original sequence can no longer be reconstructed exactly. The quantized coefficients and a description of how to generate the macroblock prediction pixel values constitute the compressed video stream. When video frames are reconstructed from the compressed stream, the compression sequence is reversed. The coefficients for each transform block 14 are converted back to spatial residuals. A prediction for each macroblock is generated based on the description in the stream and added to the residuals to reconstruct the pixels for the macroblock. Because of the information lost in quantization, however, the reconstructed pixels differ from the original ones. One of the goals of video compression is to minimize the perceived differences as much as possible for a given compression ratio. In block-based video compression the differences in the reconstructed images tend to be most obvious at the edges of the macroblocks 12 and the transform blocks 14 . Because the blocks are compressed and reconstructed separately, errors tend to accumulate differently on each side of block boundaries and can produce a noticeable seam. To counteract the production of a noticeable seam, the MPEG-4 part 10 video compression standard includes a deblocking filter. A definition of the deblocking filter can be found in Section 8.7 of the MPEG-4 part 10 video compression standard. The deblocking filter blends pixel values across macroblock and transform block edges in the reconstructed frames to reduce the discontinuities that result from quantization. Filtering takes place as part of both the compression and decompression processes. Filtering is performed after the video frames are reconstructed, but before the reconstructed frames are used to predict macroblocks in other frames. Because filtered frames are used for prediction, the filtering process must be exactly the same during compression and decompression or errors will accumulate in the decompressed video frames. The definition of the deblocking filter in the MPEG-4 part 10 specification specifies that macroblocks are filtered in raster order (i.e., from left to right and top to bottom of the video frame). Because the macroblocks are filtered in raster order, the inputs to the deblocking filter include pixels that were already filtered as part of a previous macroblock. The inclusion of already filtered pixels as inputs to the deblocking filter implies sequential processing of the macroblocks in a frame in the specified raster order. The MPEG-4 part 10 deblocking filter improves both the perceived quality of the reconstructed image and the compression ratio, but requires additional processing. When performed sequentially, the deblocking filter processing can significantly increase the time required to encode and decode each frame. It would be desirable to filter an arbitrary number of macroblock-size areas in a single video frame at the same time to reduce the time required to filter the frame. SUMMARY OF THE INVENTION The present invention concerns a method for implementing a deblocking filter comprising the steps of (A) providing an input buffer storing an unfiltered video frame, (B) providing an output buffer configured to store a filtered video frame, (C) reading pixel values for a plurality of macroblocks from the input buffer into a working buffer, (D) sequentially processing the pixel values in the working buffer through a plurality of filter stages using an array of parallel processors, where each of the plurality of filter stages operates on a different set of pixel values in the working buffer and (E) writing pixel values from a final output region of the working buffer to a respective filter output region of the output buffer. The objects, features and advantages of the present invention include providing a method and/or architecture for efficiently implementing a MPEG-4 AVC deblocking filter on an array of parallel processors that may (i) use multiple processors to filter an arbitrary number of macroblock-size areas in a single video frame at the same time, (ii) reduce the time taken to filter a frame, (iii) utilize separate storage buffers for unfiltered and filtered video frames, (iv) utilize a sequence of stages to generate output pixel values, (v) alternate between filtering across vertical edges and filtering across horizontal edges, (vi) process multiple columns of pixels at the same time when filtering across horizontal edges, and/or (vii) process multiple rows of pixels at the same time when filtering across vertical edges. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which: FIG. 1 is a diagram illustrating division of a video frame into macroblocks and transform blocks; FIG. 2 is a diagram illustrating an array of parallel processors on which a filter in accordance with an example embodiment of the present invention may be implemented; FIG. 3 is a diagram illustrating filter input and output regions in accordance with an example embodiment of the present invention; FIG. 4 is a diagram illustrating an arrangement of 3×3 filter regions in a video frame; FIG. 5 is a diagram illustrating a number of filter processing steps in accordance with an example embodiment of the present invention; and FIG. 6 is a diagram illustrating simultaneous filtering of pixel rows. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In an example embodiment of the present invention, multiple processors may be used to filter an arbitrary number of macroblock-size areas in a single video frame at the same time. For example, deblocking filter logic as specified in ISO/IEC 14496-10 (MPEG-4 part 10—Advanced Video Coding) may be implemented using parallel processors. The use of parallel processors allows simultaneous processing of all pixel blocks in a video frame. The use of multiple processors may reduce the amount of time taken to filter the frame in proportion to the number of processors used. Examples of systems in which a filter in accordance with an embodiment of the present invention may be implemented can be found in co-pending non-provisional U.S. patent applications: U.S. Ser. No. 12/342,145, entitled “Video Encoder Using GPU,”, filed Dec. 23, 2008, U.S. Ser. No. 12/058,636, entitled “Video Encoding and Decoding Using Parallel Processors,”, filed Mar. 28, 2008 now U.S. Pat. No. 8,121,197; U.S. Ser. No. 12/189,735, entitled “A Method For Efficiently Executing Video Encoding Operations On Stream Processor Architectures,”, filed Aug. 11, 2008; each of which is herein incorporated by reference in their entirety. Referring to FIG. 2 , a diagram is shown illustrating a system in accordance with an example embodiment of the present invention. In one example, separate storage buffers may be utilized for input (unfiltered) and output (filtered) video frames. For example, an architecture 100 in accordance with an example embodiment of the present invention may comprise a parallel processor array (PPA) 102 and storage medium 104 . The storage medium 104 may contain an input buffer 106 and an output buffer 108 . The parallel processor array 102 may comprise, in one example, a plurality of single instruction multiple data (SIMD) processors 110 . The plurality of SIMD processors 110 may be configured to perform deblocking filter processing on a video frame using a filter kernel. A set of program instructions for the parallel processor array 102 may be referred to as a kernel. In one example, the filter kernel may implement a deblocking filter that is compliant with the MPEG-4 part 10 AVC standard using the parallel processor array 102 . In one example, the plurality of SIMD processors 110 may read unfiltered pixels from the input buffer 106 and write filtered pixels to the output buffer 108 . Referring to FIG. 3 , a diagram is shown illustrating example filter input and output regions in accordance with an example of an embodiment of the present invention. A minimum portion of a video frame that may be filtered separately from and in parallel with the remainder of the video frame may be referred to as a filter region. The minimum filterable region is the smallest region that can be filtered independently of the rest of the video frame. In one example, the minimum filterable region may be the size of a single macroblock. However, specific implementations may be configured to filter larger regions, provided the larger regions contain integer numbers of the minimum filterable region. For example, the example illustrated in FIG. 3 uses filter regions that are 3 times as high and wide as the minimum filter region. Input pixels for each filter region may be read from a filter input region 120 of the input buffer 106 . Corresponding output pixels for the filtered area may be written to a filter output region 122 within the output buffer 108 . Macroblock boundaries 124 (thinner solid lines) and transform block boundaries 126 (dotted lines) are shown for reference. The dimensions of the filter input region 120 and the filter output region 122 are shown relative to an upper-left macroblock. In one example, the filter input region 120 may have dimensions of 21 horizontal pixels by 29 vertical pixels. An upper left corner of the filter input region 120 may be six pixels down and six pixels right of an upper-left corner of the upper-left macroblock. The filter output region 122 may be 16 by 16 pixels. An upper-left corner of the filter output region 122 may be located three pixels right of and nine pixels below the upper-left corner of the filter input region 120 . In one example, each of the filter regions in a video frame may be filtered by a separate processor 110 . Alternatively, multiple filter regions may be filtered using a single processor 110 . Referring to FIG. 4 , a diagram is shown illustrating an example video frame 200 with filter regions arranged into 3 by 3 groups. Boundaries 202 of the 3 by 3 filter regions (indicated by thicker lines) generally do not align with the macroblock boundaries 204 or the boundaries of the video frame. Because the boundaries do not align, partial filter regions may occur at the edges of the video frame 200 . If separate processors are allocated to the partial regions, the processors generally have fewer pixels to filter and may be underutilized when compared to processors allocated to whole regions. The underutilization of the processors allocated to the partial regions may be rectified by assigning partial region pairs to the same processor to increase the pixels available for filtering. For example, a simple approach may be to form partial region pairs 206 by pairing partial regions from the top and bottom of the same column, or the left and right of the same row. Referring to FIG. 5 , diagrams are shown illustrating a number of filter processing steps in accordance with an example embodiment of the present invention. The processing for each filter region in a video frame may be performed in a number of filtering steps or stages. In one example, six stages 300 , 302 , 304 , 306 , 308 and 310 may be implemented. The stages 300 , . . . , 310 may be used in sequence to process each filter region. Processing for each filter region in a video frame may be performed using a working buffer 312 having dimensions similar to the filter input region 120 (described in connection with FIG. 3 ). The working buffer 312 may be loaded initially with pixels from the input video frame buffer 106 at the beginning of filter processing. The order in which pixel values are computed within the working buffer 312 is generally important for the filter to generate output pixel values compliant with the MPEG-4 part 10 AVC specification. Each of the stages 300 , . . . , 310 reads pixel values from the working buffer 312 , computes filtered pixel values based upon the pixel values read, and writes the filtered pixels back to a respective stage output region 314 of the working buffer 312 . The filtration of individual pixels may be performed according to the process described in section 8.7 of the MPEG-4 part 10 AVC specification. A general description of the filtering process may be as follows. Pixel values may be computed using an adaptive multi-tap filter applied at right angles to the edge being filtered. Up to 4 pixels on each side of the edge may be used as the filter input, and filtered values may be computed for up to three pixels on each side of the edge. The specific filter technique used may be determined based upon the type of edge being filtered (e.g., macroblock or transform block), the input pixel values and the prediction method and degree of quantization used to generate the input pixels. The respective stage output regions 314 for each of the stages 300 , . . . , 310 are illustrated with thick borders. When processing of the particular filter region is complete, the pixels from a filter output region 318 of the working buffer 312 may be written out to the output video frame buffer 108 . The output pixels from a particular stage generally form the input pixels to the following stage. In some cases, pixels that lie outside the final filter output region 318 may be processed to generate intermediate results that may be used to compute the pixels within the filter output region 318 . In one example, the stages 300 , 304 and 308 may filter data across vertical macroblock/transform block edges, and the stages 302 , 306 and 310 may filter data across horizontal edges. Dotted lines are shown in FIG. 5 to generally illustrate edges 316 that may influence the output pixel values for each step/stage. Within each of the filtering stages, pixels are generally processed sequentially from left to right for vertical edges, and from top to bottom for horizontal edges. The filteration of individual pixels is generally compliant with section 8.7 of the MPEG-4 part 10 specification. For example, pixel values may be computed using an adaptive multi-tap filter applied at right angles to the edge being filtered. Up to 4 pixels on each side of the edge may be used as the filter input, and filtered values may be computed for up to three pixels on each side of the edge. The specific filter technique used may be determined based on the type of edge being filtered (e.g., macroblock or transform block), the input pixel values and the prediction method and degree of quantization use to generate the input pixels. In one example, the location and size of the respective output regions 314 for each of the filtering stages 300 , . . . , 310 may be summarized as in the following TABLE 1: TABLE 1 Region X Y Width Height Stage 300 3 0 5 29 Stage 302 Upper 3 3 7 5 Stage 302 Lower 3 19 7 5 Stage 304 Upper 7 3 12 7 Stage 304 Lower 7 19 12 7 Stage 306 Upper 3 7 7 12 Stage 306 Lower 3 23 7 5 Stage 308 Upper 7 10 12 9 Stage 308 Lower 7 26 12 3 Stage 310 10 7 9 18 All dimensions in TABLE 1 are in pixels. X and Y values represent the location of the upper-left corner of the particular region as measured from the upper-left corner of the working buffer (zero-based). The method in accordance with embodiments of the present invention generally allows additional parallelism within each of the stages 300 , . . . , 310 when multiple processors or processors with single instruction/multiple data (SIMD) capability are used. For example, in the steps that filter across vertical edges (e.g., stages 300 , 304 and 308 ), all rows of pixels may be processed at the same time. In the steps that filter across horizontal edges (e.g., stages 302 , 306 and 310 ), all columns of pixels may be processed at the same time. Referring to FIG. 6 , a diagram is shown illustrating the level of parallelism for the case of the third filtering step 304 in FIG. 5 . Rows of pixels 404 that may be processed simultaneously in the step 304 are shown within the stage output region 402 for the filtering step. The filter input region 400 is shown for reference. As used herein, the terms “simultaneous” and “simultaneously” are meant to describe events that share some common time period, but the term is not meant to be limited to events that begin at the same point in time, end at the same point in time, or have the same duration. The functions illustrated in the diagrams of FIGS. 5 and 6 may be implemented using one or more of a conventional general purpose processor, digital computer, microprocessor, microcontroller, RISC (reduced instruction set computer) processor, CISC (complex instruction set computer) processor, SIMD (single instruction multiple data) processor, signal processor, central processing unit (CPU), arithmetic logic unit (ALU), video digital signal processor (VDSP) and/or similar computational machines, programmed according to the teachings of the present specification, as will be apparent to those skilled in the relevant art(s). Appropriate software, firmware, coding, routines, instructions, opcodes, microcode, and/or program modules may readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant art(s). The software is generally executed from a medium or several media by one or more of the processors of the machine implementation. The present invention may also be implemented by the preparation of ASICs (application specific integrated circuits), Platform ASICs, FPGAs (field programmable gate arrays), PLDs (programmable logic devices), CPLDs (complex programmable logic device), sea-of-gates, RFICs (radio frequency integrated circuits), ASSPs (application specific standard products) or by interconnecting an appropriate network of conventional component circuits, as is described herein, modifications of which will be readily apparent to those skilled in the art(s). The present invention thus may also include a computer product which may be a storage medium or media and/or a transmission medium or media including instructions which may be used to program a machine to perform one or more processes or methods in accordance with the present invention. Execution of instructions contained in the computer product by the machine, along with operations of surrounding circuitry, may transform input data into one or more files on the storage medium and/or one or more output signals representative of a physical object or substance, such as an audio and/or visual depiction. The storage medium may include, but is not limited to, any type of disk including floppy disk, hard drive, magnetic disk, optical disk, CD-ROM, DVD and magneto-optical disks and circuits such as ROMs (read-only memories), RAMs (random access memories), EPROMs (electronically programmable ROMs), EEPROMs (electronically erasable ROMs), UVPROM (ultra-violet erasable ROMs), Flash memory, magnetic cards, optical cards, and/or any type of media suitable for storing electronic instructions. The elements of the invention may form part or all of one or more devices, units, components, systems, machines and/or apparatuses. The devices may include, but are not limited to, servers, workstations, storage array controllers, storage systems, personal computers, laptop computers, notebook computers, palm computers, personal digital assistants, portable electronic devices, battery powered devices, set-top boxes, encoders, decoders, transcoders, compressors, decompressors, pre-processors, post-processors, transmitters, receivers, transceivers, cipher circuits, cellular telephones, digital cameras, positioning and/or navigation systems, medical equipment, heads-up displays, wireless devices, audio recording, storage and/or playback devices, video recording, storage and/or playback devices, game platforms, peripherals and/or multi-chip modules. Those skilled in the relevant art(s) would understand that the elements of the invention may be implemented in other types of devices to meet the criteria of a particular application. While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.

A method for implementing a deblocking filter comprising the steps of (A) providing an input buffer storing an unfiltered video frame, (B) providing an output buffer configured to store a filtered video frame, (C) reading pixel values for a plurality of macroblocks from the input buffer into a working buffer, (D) sequentially processing the pixel values in the working buffer through a plurality of filter stages using an array of parallel processors, where each of the plurality of filter stages operates on a different set of pixel values in the working buffer and (E) writing pixel values from a final output region of the working buffer to a respective filter output region of the output buffer.

This is a division of the application Ser. No. 08/219,340 filed Mar. 28, 1994, now U.S. Pat. No. 5,447,416. FIELD OF THE INVENTION The present invention relates to a method and to a device for optimizing the pumping of a fluid flowing from a geologic formation into a drain hole extending from a wall. The device includes pumping means having at least two suction inlet holes allowing the effluent to be drawn off in at least two different zones on the length of the drain hole. The term drain hole which is used here refers to a well drilled so as to cross at least one geologic layer producing an effluent which flows and is collected through said well or drain hole. The drain hole may cross several independant producing layers or not, it may be cased or not, and in the first case, the casing may be cemented and then perforated or preperforated. BACKGROUND OF THE INVENTION Conventional pumping methods consist in setting in a well a pump plunged in the effluent produced by a geologic formation crossed by a drain hole drilled from the well. The single effluent suction point is located substantially in the vicinity of the pump. The pump delivers the effluent towards the surface by means of a tubular pipe connecting the pump to the surface. The pump is either electrically driven, and in this case, a cable lowered into the well with the pump provides the pump motor with electric power, or mechanically driven through pumping rods driven from the surface by a longitudinal reciprocating or rotational motion. The pump may be of the reciprocating piston type or a rotary pump, for example of the "MOINEAU" type. In case the drain hole crosses the layers producing the effluent over a great length, for example when the drain hole is substantially horizontal in the geologic reservoir, the pressure drops due to the flow over a great length of the drain hole may become quite significant. In this case, the conventional method tends to develop less efficiently the drain hole zones which are at the furthest distance from the suction inlet of the pump. Furthermore, when the drain hole crosses layers exhibiting permeability and/or effluent composition heterogeneities, the fluids of greater mobility will be produced in preference to the others. In the particular case of water inflows in a zone of the drain hole, the other zones located on the opposite side of the pump with respect to the water inflow zone will be inefficiently developed, if at all. It is the same when the drain hole geometry provides traps for the lighter fluids. SUMMARY OF THE INVENTION The object of the present invention is to remedy these drawbacks without requiring complex equipment difficult to implement in an oilwell. The present invention therefore relates to a device for pumping an effluent flowing through a drain hole drilled through at least one geologic layer forming a reservoir of said effluent. The device includes pumping means comprising at least two suction inlet holes spaced a predetermined distance apart so as to drain two production zones of the drain hole. The pumping means may include two pumps co-operating each with one of the two suction inlet holes. The pumping means may include a pump and means for controlling the flow rates of the effluents arriving at the pump through the two suction inlet holes. In case the device includes two pumps, they may have a common drive, for example rotating rods or rods moving in a reciprocating motion. The control means may include a valve for regulating the flows coming from the two inlet holes and the valve may be remote controlled. One of the two suction inlet holes may be located in the vicinity of the pumping means and the other may be placed at the end of a length of pipes secured with the pumping means. The device may include an annular seal means between said pipe and the wall of said drain hole, adapted for dividing the drain hole into two production zones. The invention relates to a method for pumping an effluent flowing through a drain hole. In the method, the draw off of the effluent is optimized through pumping means having at least two suction inlet holes and said inlet holes are located in two production zones of the drain hole. The flow rates of the effluents arriving at the pumping means through said two inlet holes may be controlled. Control may be steered from the surface according to measurements achieved on the flows of the effluent. The method and the device according to the invention may be applied for pumping an effluent flowing through a subhorizontal drain hole. BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will be clear from reading the description hereafter given by way of non limitative examples, with reference to the accompanying drawings in which: FIG. 1 diagrammatically shows the principle of the invention, FIG. 2 shows an embodiment according to the invention, FIG. 3 shows a variant according to the invention, FIG. 4 shows an application variant according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a well 1 drilled from the ground surface. Well 1 is extended through the producing layer 2 by a substantially horizontal drain hole 3. The rock of producing layer 2 contains an effluent to be produced which flows through drain hole 3. These flows are shown here by arrows 4. The level reached by the effluent in well 1 bears reference number 5. Pumping means 6 are plunged below level 5 so that the suction inlet holes of the pumping means are located and remain in the effluent while the effluent is driven towards the surface by the pumping means. A pipe 7 connects the pumping means to the surface. Pipe 7 has generally been used for setting and for keeping pumping means 6 in position. The effluent enters the pumping means through two suction inlet holes 8 and 9. Inlet 8 is located substantially in the vicinity of the pumping means, inlet 9 is preferably located towards the opposite end of the drain hole. An extension tube 10 secured with the pumping means forms a suction pipe. Considering the position of the pumping means, the length of this tube predetermines the position of suction inlet 9 once the pumping means are set in well 1. Of course, suction inlet 8 may also be located a predetermined distance apart from the pumping means by using another extension tube. The distance between the two suction inlets may exceed 50 m and is preferably greater than 100 m, and/or less than 3000 m, preferably less than 2000 m. Pumping means 6 may include one or two pumps, suction inlets 8 and 9 co-operating in the second case each with a pump. The pump or the pumps preferably deliver the effluent towards the surface through the inside of pipe 7. In case the pumping means include two pumps, they may also comprise separate delivery outlets requiring then two delivery pipes connecting the pumping means to the surface. Two solutions, which are not shown here since they are understandable to the man skilled in the art, may be considered : another string, parallel to string 7, or the setting of a seal means of the packer type between the outside of the barrel of pumping means 6 and the walls of well 1. In the last-mentioned solution, the delivery pipes consist, on the one hand, of string 7 and, on the other hand, of the annular pipe formed by the outside of string 7 and the inside of well 1 above the packer. The two solutions are advantageous in that the pumps may be hydraulically independant, i.e. the flow of the effluent transferred by one pump is totally separate from that transferred by the other pump. In FIG. 1, arrows 11 show the flow of the effluent coming from the producing zone 13 and flowing towards suction inlet 8, arrows 12 show the flow of the effluent coming from producing zone 14 and flowing towards suction inlet 9. The drained producing layer is thus divided into two draw off zones supplying respectively suction inlet holes 8 and 9. The position of inlets 8 and 9 in the length of drain hole 3 will be determined notably according to the geometry, the characteristics or the nature of the reservoir effluents. FIG. 2 shows the device according to the invention in which the pumping means 6 include two hydraulically independant pumps which nevertheless have a common drive. The pumps are illustrated here by two piston pump barrels 15 and 16. Pistons 17 and 18, integral with a single rod 19, are moved longitudinally and alternately by pumping rods extending rod 19 up to the surface. An appropriate surface installation, a "horsehead" type mechanical device here, moves the string of pumping rods. The string of rods is located inside string 7. Clapper valves 20 connected to pistons 17, 18 allow the effluent to flow into each upper chamber 21, 22 of pump barrels 15, 16 during the downward motion of rod 19. While the rod moves upward, the effluent is delivered from the two chambers 21 and 22 towards the inside of string 7, either substantially directly for chamber 21, or by means of pipe 25 for the lower chamber 22. A set of traveling valves 23a, 23b and of standing valves 24a, 24b completes these pumping means. Inlet 8 is shown here directly on the pump barrel, but a tube may extend the inlet of pump barrel 15 by a certain distance without departing from the scope of the present invention. The suction inlet of pump barrel 16 is located at the other end of extension tube 10. It is obvious that this variant may be adapted to other pump types, for example rotary pumps of the centrifugal or of the "MOINEAU" type. Centrifugal pumps are generally driven electrically, which requires a cable link up to the surface. The motorization may be common to the two barrels or independant, which is advantageous in this case since it allows a finer adaptation of the pumping characteristics of each barrel according to the draw off zones by regulating each motorization independantly. Positive-displacement pumps, for example of the "MOINEAU" type, are generally driven through the rotation of a string of rods driven by a surface installation. The mechanical connection of the rotors of each pump barrel will be adapted to the motion of each rotor by means of a set of knuckle joints. FIG. 3 shows another variant according to the invention, where the pumping means include a single pump barrel 28 having an inlet 26 and a discharge end 27 for the transferred effluent. A string of rods 30 drives rotor 31 into rotation by means of a knuckle joint 29. The effluent inlet 26 is supplied at the same time with the effluent drawn through inlet 8 and the effluent coming from the distant inlet at the end of tube 10. The two flows shown by arrows 34 and 35 pass respectively through adjustable-opening valves 32 and 33. Adjustment of these two valves is controlled by control means 38. Remote control of these control means from the surface allows pumping to be optimized by controlling the two flow rates. It is notably possible to totally stop one of the two flows, to balance the value of the flow rates, or to balance the pressure drops at the inlet so as to balance the draw off in the various zones of the drain hole. Remote control may be transmitted by any means known to the man skilled in the art : pressure or electromagnetic wave, electric, sonic or hydraulic means, optical fiber, etc. Bottomhole or surface measurings may be achieved in order to help to optimize pumping. It will be particularly interesting to know the dynamic pressures at the level of inlets 8 and 9 and at the level of the pumping means. These measurements may be transmitted to the surface through the same transmission means as that used for the remote control. Valves 32 and 33 may form a single valve with two inlets and one outlet, including a single adapter whose displacement opens one of the gates while it closes the other, and conversely. The variant according to FIG. 3 is not limited to only one type of pump. Any pump type adapted for being immersed in a well is suitable for the invention. The present invention is not limited to only two suction inlets. In fact, the means described may be easily transposed by the man skilled in the art into equivalent means adapted to more than two suction inlets with equivalent results. FIG. 4 shows an application to a subhorizontal drain hole 3 crossing several producing layers 36 and 37. The inlet hole 8 mainly draws off the effluent coming from layer 36, while inlet 9 draws off the effluent from layer 37. A total or partial seal means 39 connected to extension tube 10 may be located between the two layers so as to improve the specificity of each inlet. In an equivalent way, the layer developed from the suction inlet which is at the furthest distance from the pumping means may be located at a lower depth with respect to the first layer crossed by drain hole 3. This means that the drain hole is drilled according to a trajectory which goes up towards the surface. Of course, this case may also occur in a single layer.

The present invention relates to a pumping method utilizing two suction inlet holes spaced a predetermined distance apart by an extension robe. In a variant, the pumping method utilizes two pump barrels cooperating each with the two inlet holes. In another variant, the pumping method utilizes a pump barrel and control for controlling the flow rates of effluents coming from the two inlet holes. Application of the method is preferable when pumping effluent from subhorizontal drain holes.

FIELD OF THE INVENTION This invention relates to steel wire rod, steel wire, and a method of manufacturing the steel wire rod and steel wire. More particularly, this invention relates to steel cord used, for example, to reinforce radial tires, various types of industrial belts, and the like, to rolled wire rod suitable for use in applications such as sewing wire, to methods of manufacturing the foregoing, and to steel wire manufactured from the aforesaid rolled wire rod as starting material. DESCRIPTION OF THE RELATED ART In the case of steel wire for steel cord used as a material for reinforcing vehicle radial tires and various types of belts and hoses, or steel wire for sewing wire applications, the general practice is to subject a hot-rolled and controlled-cooling steel wire rod of 4-6 mm diameter to primary drawing for reducing it to a diameter of 3-4 mm, and then to subject the drawn wire rod to intermediate patenting and conduct secondary drawing for reducing it to a diameter of 1-2 mm. Final patenting is then performed, followed by brass plating and final wet drawing to a diameter of 0.15-0.40 mm. A number of extra fine steel wires obtained by this process are twisted into stranded cable, thereby fabricating steel cord. In order to lower manufacturing costs, it has become an increasingly common practice in recent years to omit the aforesaid intermediate patenting and directly draw the controlled-cooling rolled wire rod to the final patenting diameter of 1 to 2 mm. This has created a need for the controlled-cooling rolled wire rod to exhibit good direct drawing characteristics, i.e., “drawability,” so that demand for high ductility and high workability of wire rod has become very strong. Reduction of area, one index of patented wire rod ductility, is a function of austenite grain size, and since this makes it possible to improve reduction of area by refining the austenite grain size, attempts have been made to achieve austenite grain size refinement by using carbides and/or nitrides of elements such as Nb, Ti and B as pinning particles. Japanese Patent No. 2609387 teaches further improvement of extra fine wire rod toughness/ductility by incorporation of one or more of Nb: 0.01-0.1 mass %, Zr: 0.05-0.1 mass % and Mo: 0.02 to 0.5 mass % as constituent elements. In addition, Japanese Patent Publication (A) No. 2001-131697 teaches austenite grain size refinement using NbC. However, the high price of these addition elements increases cost. Moreover, Ni forms coarse carbide and nitride and Ti forms coarse oxide, so that when the wire is drawn to a fine diameter of, for example, 0.40 mm or less, breakage may occur. A study carried out by the inventors found that BN pinning is not readily capable of refining austenite grain size to a degree that affects the reduction of area. Further, Japanese Patent Publication (A) No. H8-3639 teaches enhancement of high-carbon wire rod drawability by adopting a lower patenting temperature for adjusting the wire rod structure to bainite. However, in-line bainitizing of rolled wire rod is likely to increase cost to a high level because it requires immersion in molten salt or the like and is also liable to degrade mechanical descaling ability. SUMMARY OF THE INVENTION The present invention was conceived in light of the foregoing circumstances. Its object is to provide high-strength wire rod excellent in drawability that is ideal for steel cord and sewing wire and similar applications with high productivity at good yield and low cost. This invention achieves the foregoing object by a method of manufacture constituted to enable production of the steel wire set forth in aspect 1) below and the steel for steel wire set out in aspects 2) and 3) below, and establishment of the method of producing steel wire rod set forth in aspect 4) below, and the method of manufacturing high-strength steel wire set out in aspect 5) below. 1) A high-strength steel wire rod excellent in drawability comprising a pearlite structure of an area ratio of 97% or greater and a balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and having a pearlite block size of not less than 20 μm and not greater than 45 μm. 2) A high-strength steel wire rod according to 1), comprising, in mass % C: 0.70 to 1.10%, Si: 0.1 to 1.5%, Mn: 0.1 to 1.0% Al: 0.01% or less, Ti: 0.01% or less, N: 10 to 60 mass ppm, B: not less than (0.77×N (mass ppm)−17.4) mass ppm or 5 mass ppm, whichever is greater, and not greater than 52 mass ppm, and the balance of Fe and unavoidable impurities. 3) A high-strength steel wire rod according to 2), further comprising, in mass %, one or more members selected from the group consisting of: Cr: 0.03 to 0.5%, Ni: 0.5% or less (not including 0%), Co: 0.5% or less (not including 0%), V: 0.03 to 0.5%, Cu: 0.2% or less (not including 0%), Mo: 0.2% or less (not including 0%), W: 0.2% or less (not including 0%), and Nb: 0.1% or less (not including 0%). 4) A method of manufacturing the high-strength steel wire rod according to 2) or 3), comprising: hot rolling a steel billet having the chemical composition of 2) or 3), coiling the hot-rolled steel in the temperature range between Tmin shown below and 950° C., and subjecting the coiled steel to patenting using a cooling method in which a cooling rate between 800 and 600° C. is 5° C./s or greater, T min being 800° C. when B (mass ppm)−0.77× N (mass ppm)>0.0, and T min being T min=950+1450/( B (mass ppm)−0.77 ×N (mass ppm)−10)° C. when B (mass ppm)−0.77 ×N (mass ppm)≦0.0. 5) A high-carbon steel wire excellent in ductility, which is manufactured by subjecting the steel wire rod of any of 1) to 3) to intermediate patenting and cold drawing and has a tensile strength (TS) of 2800 MPa or greater. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing how average true strain at fracture by drawing varied as a function of non-pearlite area ratio. FIG. 2 is a diagram showing how average true strain at fracture by drawing varied as a function of tensile strength. FIG. 3 is a diagram showing how average true strain at fracture by drawing varied as a function of pearlite block size. DETAILED DESCRIPTION OF THE INVENTION The inventors conducted studies regarding how the chemical composition and mechanical properties of a wire rod affect its drawability. Their findings are set out below. a) Although tensile strength can be enhanced by increasing the content of alloying metals such as C, Si, Mn and Cr, a higher content of these alloying metals lowers drawability, namely, increases breakage frequency by causing a reduction in working limit during drawing. b) Drawability exhibits good correlation with tensile strength and fracture reduction of area before drawing, i.e., after heat treatment, and very good drawability is obtained when reduction of area reaches or exceeds a certain value in correspondence to tensile strength. c) B forms a compound with N, and the amount of solid-solute B is determined by the total amounts of B and N and the heating temperature before pearlite transformation. Solid-solute B segregates at austenite grain boundaries. During cooling from the austenite temperature at the time of patenting, it inhibits generation of coarse, low-strength microstructures such as bainite, ferrite and degenerate-pearlite that originate from the austenite grain boundaries, and particularly inhibits bainite generation. Among these non-pearlite structures, bainite is the one that has the greatest adverse effect on drawability. Bainite accounts for 60% or greater of the non-pearlite structures. When solid-solute B is deficient, the foregoing effect is minimal, and when it is excessive, pearlite transformation is preceded by precipitation of coarse Fe 23 (CB) 6 that degrades drawability. This invention was achieved based on the foregoing findings. The requirements of the invention will now be explained in detail. Structure and mechanical properties of the wire rod: A study connected by the inventors revealed that the drawability of a patented wire rod is correlated with the amount of non-pearlite structures such as pro-eutectoid ferrite, degenerate-pearlite and bainite and that restraining the volume fraction of these non-pearlite structures to less than 3% inhibits occurrence of early cracking and improves drawability during drawing. The present inventors further discovered that for reducing non-pearlite structures it is effective to add B, coil the hot-rolled steel in a temperature range not lower than Tmin shown below, and subject the coiled steel to patenting using a cooling method in which the cooling rate between 800 and 600° C. is 5° C./s or greater, T min being 800° C. when B (mass ppm)−0.77 ×N (mass ppm)>0.0, and T min being T min=950+1450/( B (mass ppm)−0.77 ×N (mass ppm)−10)° C. when B (mass ppm)−0.77 ×N (mass ppm)≦0.0 This enables manufacture of a high-strength wire rod excellent in drawability having a non-pearlite volume fraction of less than 3%. It should be noted that although pearlite block size depends on both austenite grain size and pearlite transformation temperature (on cooling rate in the case of continuous cooling), dependence on transformation temperature is predominant in the case of a rolled wire rod because extreme coarsening of austenite grain size does not readily occur. From this it follows that occurrence of pearlite block coarsening means that the transformation temperature is high (cooling rate is low). When the austenite grains coarsen, coarse non-pearlite structures occur to degrade drawability even if B is added. Moreover, even when the transformation temperature is too high, coarse B carbide forms at the austenite grain boundaries before pearlite transformation, thereby degrading drawability. On the other hand, when the transformation temperature is too low (cooling rate is too high), TS becomes too high and drawability is degraded as a result. The inventors found that a pearlite block size of not less than 20 μm and not greater than 45 μm inhibits occurrence of the aforesaid non-pearlite structures and coarse B carbide and also enables a suitable TS, thereby preventing degradation of drawability. From the viewpoint of descaling ability, the coiling temperature is preferably 950° C. or less. Chemical Composition: C: C is an element that effectively enhances the strength of the wire rod. However, at a content of less than 0.70 mass %, C cannot easily be made to reliably impart high strength of 2800 MPa or greater to the final product, while uniform pearlite structure becomes hard to achieve owing to promotion of pro-eutectoid ferrite precipitation at the austenite grain boundaries. When C content is excessive, reticulate pro-eutectoid cementite arising at the austenite grain boundaries causes easy breakage during wire drawing and also markedly degrades the toughness and ductility of the extra fine wire rod after the final drawing. C content is therefore defined as 0.70 to 1.10 mass % Si: Si is an element that effectively enhances strength. It is also an element useful as a deoxidizer and, as such, is a required element when the invention is applied to a steel wire rod that does not contain Al. The deoxidizing action of Si is too low at a content of less than 0.1 mass %. When the Si content is excessive, it promotes pro-eutectoid ferrite precipitation even in a hypereutectoid steel and also causes a reduction in working limit during drawing. In addition, it hampers mechanical descaling (MD) in the drawing process. Si content is therefore defined as 0.1 to 1.5 mass %. Mn: Like Si, Mn is also an element useful as a deoxidizer. It is further effective for improving hardenability and thus for enhancing wire rod strength. Mn also acts to prevent hot brittleness by fixing S present in the steel as MnS. At a content of less than 0.1 mass % the aforesaid effects are not readily obtained. On the other hand, Mn is an element that easily precipitates. When present in excess of 1.0 mass %, it segregates particularly at the center region of the wire rod, and since martensite and/or bainite form in the segregation region, drawability is degraded. Mn content is therefore defined as 0.1 to 1.0 mass %. Al: 0.01 mass % or less. In order to ensure that the Al does not generate hard, undeformable alumina nonmetallic inclusions that degrade the ductility and drawability of the steel wire, its content is defined as 0.01 mass % or less (including 0 mass %). Ti: 0.01 mass % or less. In order to ensure that the Ti does not generate hard, undeformable oxide that degrades the ductility and drawability of the steel wire, its content is defined as 0.01 mass % or less (including 0 mass %). N: 10 to 60 mass ppm. N in the steel forms a nitride with B and thus works to prevent austenite grain coarsening during heating. This action is effectively exhibited at an N content of 10 mass ppm or greater. At too high an N content, however, nitrides form excessively to lower the amount of solid-solute B present in the austenite. In addition, solid-solute N is liable to promote aging during wire drawing. The upper limit of N content is therefore defined as 60 mass ppm. B: between 5 mass ppm or (0.77×N (mass ppm)−17.4) mass ppm and 50 mass ppm. When B is present in austenite in solid solution, it segregates at the grain boundaries and inhibits precipitation of ferrite, degenerate-pearlite, bainite and the like at the grain boundaries. On the other hand, excessive B addition has an adverse effect on drawability because it promotes precipitation of coarse carbide, namely Fe 23 (CB) 6 , in the austenite. The lower limit of B content is therefore defined as 5 mass ppm or (0.77×N (mass ppm)−17.4) mass ppm, whichever is greater, and the upper limit is defined as 50 mass ppm. The contents of the impurities P and S are not particularly defined, but from the viewpoint of achieving good ductility, the content of each is preferably 0.02 mass % or less, similarly to in conventional extra fine steel wires. Although the steel wire rod used in the present invention has the aforesaid elements as its basic components, one or more of the following optional additive elements can be positively included in addition for the purpose of improving strength, toughness, ductility and other mechanical properties: Cr: 0.03 to 0.5 mass %, Ni: 0.5 mass % or less, Co: 0.5 mass % or less, V: 0.03 to 0.5 mass %, Cu: 0.2 mass % or less, Mo: 0.2 mass % or less, W: 0.2 mass % or less, and Nb: 0.1 mass % or less (where the content ranges of Ni, Co, Cu, Mo, W and Nb do not include 0 mass %). Explanation will now be made regarding these elements. Cr: 0.03 to 0.5 mass %. As Cr reduces lamellar spacing, it is an effective element for improving the strength, drawability and other properties of the wire rod. For taking full advantage of these effects, Cr is preferably added to a content of 0.03 mass % or greater. At an excessive content, however, Cr prolongs the time to completion of transformation, thus increasing the likelihood of the occurrence of martensite, bainite and other undercooled structures in the hot-rolled wire rod, and also degrades mechanical descaling ability. The upper limit of Cr content is therefore defined as 0.5 mass %. Ni: 0.5 mass % or less. Ni does not substantially contribute to wire rod strength improvement but is an element that enhances toughness of the drawn wire. Addition of 0.1 mass % or greater of Ni is preferable for effectively enabling this action. At an excessive content, however, Ni prolongs the time to completion of transformation. The upper limit of Ni content is therefore defined as 0.5 mass %. Co: 1 mass % or less. Co is an element effective for inhibiting precipitation of pro-eutectoid cementite in the rolled product. Addition of 0.1 mass % or greater of Co is preferable for effectively enabling this action. Excessive addition of Co is economically wasteful because the effect saturates. The upper limit of Co content is therefore defined as 0.5 mass %. V: 0.03 to 0.5 mass %. V forms fine carbonitrides in austenite, thereby preventing coarsening of austenite grains during heating and improving ductility, and also contributes to post-rolling strength improvement. Addition of 0.03 mass % or greater of V is preferable for effectively enabling this action. However, when the V is added in excess, the amount of carbonitrides formed becomes too large and the grain diameter of the carbonitrides increases. The upper limit of V content is therefore defined as 0.5 mass %. Cu: 0.2 mass % or less. Cu enhances the corrosion resistance of the extra fine steel wire. Addition of 0.1 mass % or greater of Cu is preferable for effectively enabling this action. However, when Cu is added in excess, it reacts with S to cause segregation of CuS at the grain boundaries. As a result, flaws occur in the steel ingot, wire rod etc. in the course of wire rod manufacture. To preclude this adverse effect, the upper limit of Cu content is defined as 0.2 mass %. Mo: Mo enhances the corrosion resistance of the extra fine steel wire. Addition of 0.1 mass % or greater of Mo is preferable for effectively enabling this action. At an excessive content, however, Mo prolongs the time to completion of transformation. The upper limit of Mo content is therefore defined as 0.2 mass %. W: W enhances the corrosion resistance of the extra fine steel wire. Addition of 0.1 mass % or greater of W is preferable for effectively enabling this action. At an excessive content, however, W prolongs the time to completion of transformation. The upper limit of W content is therefore defined as 0.2 mass %. Nb: Nb enhances the corrosion resistance of the extra fine steel wire. Addition of 0.05 mass % or greater of Nb is preferable for effectively enabling this action. At an excessive content, however, Nb prolongs the time to completion of transformation. The upper limit of Nb content is therefore defined as 0.1 mass %. Drawing Conditions: By subjecting the steel wire rod according to the first aspect of this invention to cold drawing, there can be obtained a high-strength steel wire excellent in ductility that is characterized by having a tensile strength of 2800 MPa or greater. The true strain of the cold-drawn wire is 3 or greater, preferably 3.5 or greater. EXAMPLES The present invention will now be explained more concretely with reference to working examples. However, the present invention is in no way limited to the following examples and it should be understood that appropriate modification can be made without departing from the gist of the present invention and that all such modifications fall within technical scope of the present invention. Steel billets of the compositions shown in Table 1 were heated and then hot rolled into 4 to 6 mm-diameter wire rods. The wire rods were coiled at a predetermined temperature and patented utilizing the Stelmor process. Non-pearlite volume fraction measurement was conducted by embedding resin in an L-section of a rolled wire rod, polishing it with alumina, corroding the polished surface with saturated picral, and observing it with a scanning electron microscope (SEM). The region observed by the SEM was divided into Surface, ¼ D and ½D zones (D standing for wire diameter) and 10 photographs, each of an area measuring 50×40 μm, were taken at random locations in each zone at a magnification of ×3000. The area ratio of degenerate-pearlite portions including dispersed granular cementite, bainite portions including plate-like cementite dispersed with spacing of three or more times the lamellar spacing of surrounding pearlite portion, and pro-eutectoid ferrite portions precipitated along austenite were subjected to image processing and the value obtained by the analysis was defined as the non-pearlite volume fraction. The pearlite block size was determined by embedding resin in an L-section of the wire rod, polishing it, using EBSP analysis to identify regions enclosed by boundaries of an orientation difference of 9 degrees as individual blocks, and calculating the average block size from the average volume of the blocks. Each patented wire rod was cleared of scale by pickling and then used to prepare 10 wire rods of 4 m length imparted with a zinc phosphate coating by Bonde coating. The so-prepared rods were subjected to single-head drawing at an area reduction rate of 16 to 20% per pass using dice each having an approach angle of 25 degrees. Drawability was determined by averaging the values of the limit diameter and true strain at drawing fracture. TABLE 1 Chemical compositions (Mass % (except for B and N)) No. C Si Mn P S B(ppm) Al Ti N(ppm) Cr Mo Ni Cu V Co W Nb  1 Invention 0.70 0.30 0.45 0.019 0.025 24 0.000 0.000 20 — — — — — — — —  2 Invention 0.82 0.20 0.51 0.015 0.013 15 0.000 0.000 12 0.20 — — — — — — —  4 Invention 0.92 0.25 0.46 0.019 0.025 30 0.000 0.000 60 — — 0.10 — — — — —  5 Invention 0.87 1.20 0.5 0.008 0.007 46 0.001 0.000 50 0.20 — — — — — — —  6 Invention 1.09 0.20 0.5 0.010 0.009 25 0.000 0.001 50 0.20 — — 0.10 — — — —  7 Invention 0.92 0.60 0.5 0.025 0.020 30 0.001 0.000 25 — — — — — — 0.10 0.10  8 Invention 0.82 0.20 0.5 0.008 0.008 11 0.000 0.000 25 — — — — — — — —  9 Invention 0.82 0.20 0.5 0.008 0.008 11 0.000 0.000 33 — — 0.10 — — — — — 10 Invention 0.82 0.20 0.5 0.008 0.008 20 0.001 0.000 25 — — — — — — — — 11 Invention 0.82 0.20 0.5 0.008 0.008 20 0.000 0.000 35 — — — — — — — — A Invention 0.92 0.20 0.5 0.008 0.008 15 0.000 0.000 25 0.20 — — — 0.03 — — — B Invention 0.92 0.20 0.5 0.008 0.008 10 0.000 0.000 21 0.20 — — — 0.06 — — — C Invention 1.02 0.20 0.5 0.008 0.008 15 0.000 0.000 25 0.20 — — — 0.03 — — — D Invention 1.02 0.20 0.5 0.008 0.008 10 0.000 0.000 21 0.20 — — — 0.06 — — — E Invention 0.82 0.21 0.48 0.009 0.009 12 0.000 0.000 24 0.03 — — — — — — — F Invention 0.82 0.19 0.51 0.009 0.009 11 0.000 0.000 25 0.06 — — — — — — — G Invention 0.92 0.20 0.5 0.008 0.008 9 0.000 0.000 23 0.05 — — — 0.04 — — — H Invention 1.01 0.20 0.5 0.008 0.009 10 0.000 0.000 23 0.05 — — — 0.03 — — — I Invention 1.02 0.20 0.5 0.008 0.008 8 0.000 0.000 21 0.04 — — — — — — — 12 Comparative 0.70 0.30 0.6 0.008 0.007 11 0.000 0.000 35 — 0.20 — — — — — — 13 Comparative 0.82 0.20 0.5 0.010 0.009 2 0.000 0.010 50 0.20 — — — — — — — 14 Comparative 0.90 0.20 0.8 0.010 0.009 60 0.000 0.005 25 — — 0.10 — — — — — 15 Comparative 0.87 1.70 0.4 0.015 0.013 20 0.000 0.010 25 0.20 — — — — — — — 16 Comparative 1.30 1.00 0.3 0.015 0.013 20 0.030 0.000 25 — — — — — 0.30 — — 17 Comparative 0.92 0.30 1.5 0.015 0.013 20 0.000 0.000 25 — — — — 0.20 — — — 18 Comparative 0.82 1.00 0.5 0.025 0.020 20 0.030 0.000 35 — — — — 0.20 — — — 19 Comparative 0.96 0.20 0.5 0.010 0.009 0 0.000 0.010 25 0.20 — — — 0.10 — — — 20 Comparative 0.82 0.20 0.5 0.010 0.009 0 0.000 0.010 25 — — — — — — — — 21 Comparative 0.82 0.20 0.5 0.010 0.009 13 0.000 0.010 25 — — — — — — — — 22 Comparative 0.82 0.20 0.45 0.019 0.025 24 0.000 0.000 25 — — — — — — — — TABLE 2 Coiling or Patented Pearlite Non- Drawing heating Cooling product block Reduction RA pearlite fracture Drawing Diameter temp Patenting rate strength size of area Tmin min area ratio diameter fracture No. (mm) (° C.) method (° C./s) (MPa) (μm) (%) (° C.) (%) (%) (mm) true strain Remark  1 5.5 860 Stelmor 11 1077 30 61 800 41 1.2 1.9 2.1  2 5.5 880 Stelmor 11 1185 32 56 800 43 2.4 2.6 1.5  4 5.5 930 Stelmor 11 1277 43 55 895 37 2.5 2.9 1.3  5 5.0 850 Stelmor 12 1375 22 41 800 47 2.5 2.8 1.2  6 4.0 910 Stelmor 14 1442 37 38 888 35 2.8 2.4 1.0  7 6.0 870 Stelmor 10 1324 29 56 800 44 2.8 2.9 1.5  8 5.5 880 Stelmor 12 1196 28 55 871 45 1.3 2.7 1.4  9 5.5 900 Stelmor 12 1203 35 56 891 41 2.2 2.7 1.4 10 5.5 870 Stelmor 11 1169 24 57 800 46 2.1 2.4 1.7 11 5.5 875 Stelmor 13 1196 31 54 864 43 1.9 2.6 1.5 A 5.5 870 Stelmor 13 1274 32 49 848 43 1.9 2.9 1.3 B 5.5 870 Stelmor 13 1274 27 51 860 46 1.7 2.9 1.3 C 5.5 870 Stelmor 13 1353 30 41 848 43 1.7 2.9 1.3 D 5.5 870 Stelmor 13 1353 28 46 860 44 1.5 2.9 1.3 E 5.5 870 Stelmor 13 1195 31 44 862 43 1.6 2.8 1.3 F 5.5 875 Stelmor 13 1196 32 45 871 43 1.8 2.9 1.3 G 5.5 875 Stelmor 13 1274 29 46 873 45 2.1 2.9 1.3 H 5.5 875 Stelmor 14 1345 32 46 868 42 2.0 2.9 1.3 I 5.5 875 Stelmor 13 1353 35 42 870 40 1.6 3.0 1.2 12 5.5 850 Stelmor 10 1128 30 33 894 43 3.5 3.7 0.8 13 5.5 870 Stelmor 10 1169 34 39 919 42 4.5 3.4 1.0 14 5.5 860 Stelmor 11 1270 38 56 800 40 3.9 3.5 0.9 pro-eutectoid θ 15 5.5 870 Stelmor 12 1435 36 28 800 36 12.6 4.0 0.7 pro-eutectoid α 16 5.5 870 Stelmor 11 1657 32 23 800 22 4.7 4.1 0.6 pro-eutectoid θ 17 5.5 860 Stelmor 12 1352 26 39 800 45 3.8 3.6 0.8 micro-martensi 18 5.5 820 Stelmor 11 1305 22 39 864 49 8.2 3.3 1.0 19 5.5 905 Stelmor 11 1306 36 42 900 40 3.6 4.1 0.4 No B 20 5.5 905 Stelmor 11 1186 32 41 900 43 3.4 3.1 1.1 No B 21 5.5 885 Stelmor 40 1316 16 33 861 51 2.7 3.9 1.0 Fast cool 22 5.5 880 Air 2 1020 52 28 870 31 2.7 3.1 0.6 Slow cool Table 1 shows the chemical compositions of the evaluated products, and Table 2 shows their test conditions, austenite grain diameter and mechanical properties. In Tables 1 and 2, 1 to 11 and A to I are invention steels and 12 to 22 are comparative steels. 12 and 18 are cases in which reduction of area was low because a low coiling temperature caused B nitride and carbide to precipitate before patenting and thus make it impossible to obtain adequate solid-solute B. 13, 19 and 20 are cases in which reduction of area was low because the amount of added B was either low or nil. 14 is a case in which reduction of area was low because excessive B content caused heavy precipitation of B carbide and pro-eutectoid cementite at the austenite grain boundaries. 15 is a case in which pro-eutectoid ferrite precipitation could not be inhibited because Si content was excessive. 16 is a case in which pro-eutectoid cementite precipitation could not be inhibited because C content was excessive. 17 is a case in which micro-martensite formation could not be inhibited because Mn content was excessive. 21 is a case in which ductility was poor because an excessively high cooling rate during patenting made TS high for the C content. The high cooling rate refined the block size. 22 is a case in which ductility was poor because a low cooling rate during patenting coarsened the block size. FIG. 1 is a diagram showing how average true strain at fracture by drawing varied as a function of non-pearlite area ratio in invention and comparative steels. The invention steels were high in average true strain at fracture and exhibited good drawability. However, drawing limit also depends on TS. How average true strain at fracture by drawing varied as a function of tensile strength is therefore shown in FIG. 2 . A comparison of the invention and comparative steels at the same TS shows that the invention steels were higher in average true strain and exhibited superior drawability. FIG. 3 relates to those among the steel wire rods having chemical compositions and heating conditions falling within the ranges of the present invention that were examples whose TS was within the range of 1000 to 1300 MPa. The diagram shows how average true strain at fracture by drawing varied as a function of pearlite block size. Superior drawability was exhibited when pearlite block size was in the range of not less than 20 μm and not greater than 45 μm. In FIGS. 1 to 3 , ♦ indicates an invention steel and □ represents a comparative steel. This invention enables manufacture of steel cord usable as a reinforcing material in, for example, radial tires, various types of industrial belts, and the like, and also of rolled wire rod suitable for use in applications such as sewing wire.

The invention provides wire rod excellent in drawability and steel wire made from the wire rod as starting material with high productivity at good yield and low cost. A hard steel wire rod of a specified composition is hot rolled, the hot-rolled steel is coiled in a specified temperature range, and the coiled steel is subjected to patenting at a predetermined cooling rate, thereby affording a high-carbon steel wire excellent in workability. It is high-strength steel wire excellent in drawability comprising a pearlite structure of an area ratio of 97% or greater and the balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and having a pearlite block size of not less than 20 μm and not greater than 45 μm. The invention also provides a high-carbon steel wire excellent in ductility, which is manufactured by subjecting the wire rod to intermediate patenting and cold drawing and has a tensile strength of 2800 MPa or greater.

BACKGROUND AND FIELD OF THE INVENTION In the textile industry, there are many production machines in which a large number of production units are in operation at the same time. As examples may be mentioned spinning machines, bobbin winding machines and yarn twisting machines. There is an obvious need for automatic monitoring of each individual production unit for the smooth progress of production and the quality produced. For checking the production process, the most important factor to monitor is thread breakage, and for quality control the most important factor is the cross-section of the twisted yarn which serves as a check on whether all the threads have been twisted in. Although the term "thread" is consistently used in the following description, it should be understood to include all products of spinning, such as yarns, twisted threads or yarns, strands, filaments, and the like. The above-mentioned monitoring of all the individual production units could be technically solved with known means but has hitherto not been realized on account of the costs involved. Owing to the large number of production units only a minimum expenditure of cost per production unit would be affordable if the cost per machine is to be kept within acceptable limits. For detecting thread breakage in ring spinning machines, installations which have so-called travelling sensors have recently appeared on the market. These are able to monitor the movements of the ring traveller of a whole side of a ring spinning frame with a single sensor. This solution is acceptable from the point of view of cost for detecting thread breakage but it cannot be used for measuring other thread parameters because the signal is produced by the rotating ring traveller and not by the thread itself. No economically feasible solutions have hitherto been found for determining the thread cross-section and/or its non-uniformity directly at the production unit of ring spinning frames, twisting frames, and the like. SUMMARY AND OBJECT OF THE INVENTION An object of the invention is to provide a process and apparatus which enables the production and quality of production units on multi-spindle textile machines to be monitored at an acceptable cost. The invention relates to a process for production and quality control of the production units of multi-spindle textile machines, in which the production units are arranged in a row and the thread traveling in each production unit executes a transverse movement to form a sort of balloon describing the surface of a rotationally symmetrical body which will hereinafter be referred to as a space element. The process according to the invention is characterized in that a monitoring device carrying a beam of light is provided for each of a plurality of groups of two or more production units. Within each group, the beam of light is passed through all the space elements at the production units of the group and is therefore intermittently interrupted or attenuated in each space element by the moving thread. The resulting shading or reduction in intensity of light is converted into an electric signal in a receiver and used as basis for further interpretation. The basic idea of the invention is therefore that several production units are monitored by a common monitoring system so that the costs per production unit are considerably reduced. One beam of light is in each case passed through several thread balloons, the cross-section of the beam being preferably small in proportion to the diameter of the balloon. When the textile machine is in the operational state, each thread passes through the light beam twice with each revolution. There is a high degree of probability that there will be a certain point in time when only one single thread is situated in the path of the beam. The smaller the number of production units, the higher is this probability, but it is absolutely necessary for each thread to traverse the beam entirely on its own because otherwise the measurement would be falsified. Since the movements of rotation of the individual threads are generally not accurately synchronized but take place at random, the chance of each individual thread being measured at some point in the course of time is in fact a certainty. In textile machines with a very large number of production units in a row (for example above 100), it is advisable not to pass the light beam through all the balloons but to subdivide them into several groups. The size and number of these groups is a matter of judgment and will be determined by practical parameters. In particular, the probability of only one thread lying in the path of the beam progressively decreases as the number of production units increases and if the distance between transmitter and receiver increases then the intensity of light may become insufficient. This does not apply, of course, to laser beams. This invention also relates to an apparatus for carrying out the above-mentioned process comprising a monitoring device. The apparatus according to the invention is characterized in that two or more production units are allocated to a common monitoring device which comprises a transmitter for a beam of rays and a receiver for this beam and is so arranged that the beam passes through the space elements at the aforesaid two or more production units, and means are provided for evaluating the fluctuations in intensity of the beam occurring at the receiver. In one mode of evaluation, the goal is to monitor the textile apparatus for thread breaks and the like. Since each passage of a thread through the light beam results in the production of an electrical impulse, a diminution in the number of impulses produced in a selected time interval may be used as an indication that not all of the production units in the group being monitored are forming balloons in the intended manner. In such evaluations, statistical procedures may be used to guard against false indications such as might occur if one did not take into account the unlikely possibility of threads from more than one production unit crossing the light beam at the same moment to produce only one electrical impulse instead of the expected two impulses. For example, the probability of a false indication may be reduced by withholding a thread break indication until multiple impulse counts over a plurality of spaced apart time intervals have all shown deficiencies from the expected number of impulses. It also is a feature of the invention that, when desired, the evaluation system have a capability of distinguishing impulses formed by one thread from impulses formed by other threads being processed in the group of production units being monitored in common by a single system. By suitably arranging the light path in relation to the balloons at the several production units, one can cause the impulses derived from one thread to differ from other impulse in their shapes and/or in their timing. In this way the evaluation system may provide information (e.g., thread presence or absence, thread diameter, etc.) about the threads at identified ones of the production units being monitored in common. BRIEF DESCRIPTION OF THE DRAWINGS The invention is described below with the aid of exemplary embodiments and the drawings, in which FIG. 1a is a schematic plan view of a number of production units, FIG. 1b is a side view of the production units of FIG. 1a seen from the left, FIG. 2 is a first impulse diagram, FIGS. 3a 3b show a first variation of the arrangement of FIG. 1a in plan view and in side view, FIG. 4 is a second impulse diagram, FIG. 5 shows a second variation of the arrangement of FIG. la in plan view, FIG. 6 is a third impulse diagram, FIG. 7 shows a third variation of the arrangement of FIG. 1a in plan view, FIG. 8 shows a constructional detail of a production unit, FIGS. 9-11 show each a further variation of the arrangement of FIG. 1a in plan view, FIG. 12a and 12b represent examples of impulse forms, FIG. 13a and 13b shows examples of positions of the thread in the beam, and FIG. 14 shows another variation of the arrangement of FIG. 1a in plan view. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIGS. 1a and 1b show schematically four production units 21, 22, 23 and 24 which consist of spindles of a ring spinning frame. The figures show the ring rail 10, the ring 11, a thread guide 12 (the so-called piglet's tail) and a spindle 16. At each production unit, a thread 1, 2, 3, 4 runs from the thread guide 12 to the ring 11 and forms a balloon 13 in which it is situated at any given moment in an instantaneous position such as 31, 32, 33 or 34. The four production units 21 to 24 arranged in a row are allocated to a common monitoring device which comprises a transmitter 5 for a beam of light 7 and a receiver 6 for this beam. The beam 7 passes through the center of the balloon 13 and is therefore repeatedly traversed by each rotating thread 1 to 4, in fact twice per rotation. Each intersection of the beam by a thread is accompanied by an attenuation or shading of the light received by the receiver 6. In the textile machines to which this description is applicable, all the balloons of a given machine rotate at about the same speed but their rotation is not synchronized. The time for one revolution is therefore known at least approximately. If a monitoring device is provided for four production units, as in the examples illustrated, and shading occurs eight times (2 times 4) per revolution, then all the threads are intact. FIG. 2 shows a corresponding impulse diagram in which the time t is plotted along the abscissa and the shading A of the beam by the threads 1, 2, 3 and 4 is plotted along the ordinate. Each shading by one of the threads 1 to 4 is represented symbolically by a shading impulse A1 to A4, and A1' to A4'. The impulse sequence is purely arbitrary but the impulses are always separated by a half period of 180°. It is purely by way of example that the beam 7 is shown to pass through the center of the balloon 13. The beam could equally well be shifted in a parallel direction, for example, or placed obliquely as in FIGS. 3a and 3b to enclose an angle a with the horizontal H and an angle b with the line K connecting the axes of the production unit 21, 22, 23 and 24. For certain purposes, more than one beam may be used. Several beams may be produced by a single light transmitter 5 with several light-sensitive receivers 6, 6' (FIG. 5) or with several light transmitters 5 and a single light-sensitive receiver 6. The description given below is limited to only a few examples. From the time sequence and the intensity of the shading impulse, conclusions can be drawn as to the diameter of the thread. The description will first be confined to the determination of thread breakages. Additional explanations necessary for determining the thread cross-section will be given at the end of the examples. With the recognition of a thread breakage within a production group, the problem is only partly solved. The second part of the problem lies in detecting the position in the production units 21, 22, 23, 24 where the thread breakage occurred, i.e. in identifying the production unit. This problem may be solved, for example, in an arrangement shown in FIG. 3a. The beam 7 in this case does not pass through the center of the thread balloon but at various distances from the center. In contrast to FIG. 1, in which a possible thread breakage is detected after exactly one half period of rotation, the time for detection varies in this example. It will easily be seen that the intervals between impulses always correspond to an angle c or an angle representing the difference between 360° and the angle c. A corresponding impulse diagram is shown in FIG. 4, in which the different angles are also represented. The interpretation of the individual impulses, i.e. the relationship between them, requires care. If sufficient time is available for evaluation, the problem may be solved by statistics. In general, a thread breakage need not necessarily be detected with the first revolution. When a sufficiently large number of revolutions have taken place, displacements invariably occur due to the non-synchronous movement of the individual production units so that the production unit affected can be identified completely according to the laws of statistics, e.g. by autocorrelation. Determination of the thread which has caused shading can be considerably facilitated by using a second light beam. This may be realized as shown in FIG. 5 by using one transmitter 5 with two receivers 6, 6' or by using two transmitters with one receiver. In either case, two diverging or converging beams 7, 8 are obtained. It is, of course, also possible to use two transmitters 5 and two receivers 6. Since, as already mentioned, the speeds of rotation of all the balloons are approximately equal, the positions of the production units 21, 22, 23, 24 can be reliably determined from the time which elapses between the passage of the thread through the beam 7 and its passage through the beam 8. Thus, in FIG. 5 the impulses are obviously very close together in spindle 21 and furthest apart in spindle 24. The distance between the locations of the impulses in each case corresponds to an angle e (e1, e2, e3, e4) and their allocation to the appropriate spindle is obvious. FIG. 6 shows the impulse diagrams of the shadings in the two beams 7, 8. A case could arise that by coincidence certain impulses could be allocated to any of several spindles. In that case, the allocation of impulses to spindles should first be confined to those cases which are completely clear, and further measurements may then be carried out at a later stage when the positions of the threads in relation to one another has completely changed. The probability of the magnitude of the time interval within which the presence of all the threads can be determined may be calculated according to the laws of statistics. In order to determine even more easily and unequivocally which individual shading impulses belong to which spindles, the arrangement of FIG. 5 may be modified as shown in FIG. 7 in which an additional transmitter 25 is provided between the two receivers 6, 6' (FIG. 5) and an additional receiver 26 and 26' respectively, is arranged on each side of the transmitter 5. Two pairs of beams 7, 8 and 7', 8', then pass through the balloons. Interpretation of the shading impulses at the receivers 6, 6' and 26, 26' is carried out separately for each pair of receivers in the manner described for FIGS. 5 and 6 and the signals of the two pairs of receivers are brought into relationship with one another. The allocation of the shading impulses to the individual spindles then becomes clearer and more reliable but the costs are also higher. In many production machines, the individual production units are separated from one another by separators. This is shown in FIG. 8 on a ring spinning machine which is used as an example. The balloon 13 between the thread guide 12 and the ring 11 forms on the ring rail 10 as in FIG. 16 but in this case the ring rail 10 carries an opaque separator 14 for each spindle. Moreover, the spindle 16 is longer than in FIG. 1b so that the light beam 7 cannot be passed centrally through the balloon 13, at least not in the lower part of the balloon. The beam 7 in this case is situated laterally to the spindle 16, just above the formation of the cops, and the separator 14 has an opening 15 for the passage of the light beam. FIG. 9 shows a possible position of two beams 7, 8 laterally to the spindles 16. FIG. 10 shows the arrangement of FIG. 9 in greater detail. A beam emitter, for example a luminescence diode, is indicated at 17 and the direction of the beams 7, 8 is indicated by the arrow 18. Beams of this kind generally fan out widely (with the exception of laser beams). The beams therefore strike the receiving elements 19 and 20, which may be conventional commercially available photoelectric diodes. The beam 7 is formed between the transmitter 17 and the receiving element 19 while the beam 8 is formed between the transmitter 17 and the receiving element 20. Electrical impulses are thereby produced, as shown in FIGS. 2, 4 and 6. The basic principle applies that the difference in time enables the production unit to be identified while the magnitude of shading is a measure of the diameter of the thread. The processing of electric impulses is well known and need not be described here except to mention that the shading is manifested as a voltage or a current impulse which is easily measured. The time difference between the impulses are pure time measurements which can be carried out very accurately by simple means. The voltage or current can easily be converted into binary signals which together with the time measurements provide ideal conditions for electronic data processing. Microprocessors are particularly suitable for this purpose. In FIGS. 1a, 3a, 3b, 5, 7 and 9 the beams are only shown schematically as straight lines with point cross-section but in practice the cross-section of the beams 7, 8 is determined by the luminous surface of the transmitter 17 and by the surface area of the receiving elements 19 and 20. If these two areas are approximately equal in magnitude, then the impulses of the individual production units are independent of their position, and their interpretation is thereby simplified. The two surfaces could, however, be deliberately made unequal. For example, as shown in FIG. 11, the transmitter 17 could have a small surface area and the receiving element 19 a large surface area (or conversely). Identification of the production unit is then possible from the length and/or height of the impulse. Interpretation of the impulse then becomes slightly more complicated but on the other hand only a single light transmitter and a single receiving element are required. FIG. 12a shows an impulse of the type produced in the production unit 21 of FIG. 11 while FIG. 12b shows a corresponding impulse from production unit 24 (FIG. 11). In all the examples described here, only four production units are shown. This number may easily be increased but is limited by the reliability of allocation of an impulse to the correct production unit, which decreases with increasing spindle number. As a general rule, the upper limit of the number of production units would be about 16. In a machine with, for example, 160 production units, this would require 10 groups of 16 production units each. The cost for each group is then minimal because the interpretation can then advantageously be carried out centrally. Inexpensive systems can be constructed by this arrangement. The number of production units may be further limited by problems of optics since the intensity of light decreases with the square of the distance between the receiver and the transmitter. Interfering light and noise may then overshadow the useful signal. A considerable improvement may be achieved by modulating the light in known manner to cut out extraneous influences. The previous embodiments were used only for detecting thread breakages but the magnitude of the shading is also a measure of the diameter of the thread in the light beam. Moreover, even when the transmitter surfaces and the receiver surfaces are equal, the intensity of the shading depends not only on the diameter but also on the position of the thread between the transmitter and the receiver. This is illustrated in FIG. 13, in which the transmitter 17 sends its light to the receiver 19 and the thread 1 is situated in the immediate vicinity of the receiver 19 (FIG. 13b). In that case, the shading is almost equal to the diameter of the thread 1. In FIG. 13a, on the other hand, the thread 1 is situated approximately halfway between the receiver 19 and the transmitter 17. It is clear that in this case the area of shading is larger (almost double). This property may be used to identify the production unit of the particular thread if it can be assumed that the thread diameter is sufficiently constant (or if a mean value is obtained from several passages of the thread). For a given diameter, a given area of shading corresponds exactly to a particular position of thread. If there is a change in thread diameter due to non-uniformities then the size of the shading also changes. Since the thread also moves through the balloon in the longitudinal direction, the light scans a different part of the thread on each occasion. The known parameters of quality, such as the coefficient of variation of non-uniformity, the spectrogram, etc. can then be calculated from a sufficient number of scanning points. A continuous impulse sequence without gaps is not necessary. Interruptions are permissible since sufficient material and time are available for interpretation in an on-line method of measurement. In the case of twisted yarn, it is sometimes necessary to check the presence of all the individual threads of the yarn. The absence of one or other thread component or the presence of an additional thread component alters the diameter of the thread and therefore the area of shading. It is therefore possible to determine whether the number of individual thread components is correct. It may sometimes occur that a production unit produces a thread of a different fineness by mistake. In that case, the thread from this production unit would give rise to a different area of shading than a thread of the correct fineness. It is therefore also possible to detect production units producing threads of the wrong degree of fineness. By including the area of shading in the calculation it is therefore possible at quite low cost not only to detect thread breakages but also to carry out an extensive quality control of each production unit. FIG. 14 shows another possible arrangement for the position of the light beam passing through the balloon, in which the beam 7 passes from the transmitter 5 to a mirror 9 and from there as reflected beam 7' to a receiver 6. The impulse sequences are similar to those of the examples shown in FIG. 5. Only one transmitter and one receiver are required in this case but the beam 7 is twice as long. Still other modifications and variations will be apparent to persons skilled in the art. Accordingly, the foregoing description of the illustrated embodiments is intended as exemplary only, and the scope of the invention is to be ascertained from the following claims.

A common monitoring system with a light beam is provided for a group of two or more production units arranged in a row. The beam passes through the thread balloon formed by the moving thread of each of these production units and is intermittently interrupted or attenuated by the moving thread in each balloon. The resulting shading is converted into an electric signal in a receiver of the monitoring system. The threads of the individual production units can be identified by evaluating the relationships of amplitude, time and phase between the individual shading impulses. The process enables on-line production and quality control to be carried out on multi-spindle textile machines such as ring spinning machines at an acceptable cost.

BACKGROUND OF THE INVENTION The growth in acceptance of computers has resulted in increased numbers on non-programmers using computers every day. Computers are a part of life in the workplace, in the schools and in the homes and the reduced experience levels of computer users has imposed a requirement for enhanced user interfaces. Graphical user interfaces are designed to make human interactions with computers more intuitive. They convey information to users by way of a monitor or display device by various combinations of graphical items. Examples of graphical user interfaces (or GUIs) are those provided with operating systems such as IBM's OS/2® 1 and Microsoft's Windows 95® 2 . These operating systems rely on a ‘window-based’ workspace for displaying application programs, operating system information and program groupings. 1 OS/2 is a registered trademark of International Business Machines Corporation. 2 Windows 95 is a registered trademark of Microsoft Corporation. Current window-based workspaces utilize vertical scroll controls having a sliding scroll control tab to move the contents of a window into view as is shown in FIG. 1 . FIG. 1 depicts a window 101 containing a list of related items having three tiers 103 utilizing the currently known window based workspace scroll controls. On the right hand side of the window 101 is a sliding scroll control 111 having an up arrow 113 which can be selected to scroll the related information upward, a down arrow 115 which can be selected to scroll the related information downward, and a bar 117 which indicates the proportion of the information currently displayed on the screen and allows the user to select the bar 117 and drag it for expedited traversal of the related information. This sliding scroll control tab adds to the overall visual clutter of the desktop and, with present implementations, consumes a fixed amount of space and remains on screen throughout the existence of the window. An additional disadvantage of the sliding scroll control tab is that its operation requires frequent pointer repositioning. It also requires a separate window frame for the scrolling mechanisms and these mechanisms (the up and down controls and the scroll slider) are physically separate such that significant movement of the pointer is required to fine-tune a scroll operation. SUMMARY AND OBJECTS OF THE INVENTION It is an object of the present invention to create an inline method of scrolling through associated elements. It is a further object that this inline scroll control be minimally invasive and utilize minimal screen space. It is a further object of the present invention to provide continuous feedback to the user of the progress of the traversal through the related objects. It is yet a further object of the present invention to reduce the required pointer movement so that use on a notebook computer using pointers such as a track point become easier. These and other objects of the present invention are provided by the inline scroll control described herein. The inline scroll control provides a method, apparatus and program product for incorporating scroll control directly into a list of related objects such as desktop folders or directories. It does not rely on the window-based paradigm of prior scrolling methods and provides less clutter on the desktop for the user of the GUI. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an example of a traditional window sliding scroll control (Prior Art). FIG. 2 is a flow chart of the logic for a bottom scrolling indicator. FIG. 3 is a flow chart of the logic for a top scrolling indicator. FIG. 4 is a flow chart for cursor detection. FIG. 5 is a flow chart depicting logic for indicating a control arrow using a pointing device. FIG. 6 a is an example of a scroll bar indicator for movement in both directions. FIG. 6 b is an example of a scroll bar indicator for movement in the downward direction only. FIG. 7 is another example of the indicator of the present invention. FIG. 8 is an example of the indicator of the present invention with significant room for downward scrolling and a status bar indication. FIG. 9 is an example of the inline scroll control of the present invention demonstrating multidirectional scrolling capabilities using the proportional directional arrows. FIG. 10 a is another example inline scroll control of the present invention. FIG. 10 b depicts the stationary aspect of the scroll control as the information is scrolling. FIG. 10 c depicts the control snapping inline once the control is released. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention will now be described in more detail with reference to the accompanying drawings in which preferred embodiments of the invention are shown. Like numbers in different figures represent the same item. It will be obvious to one skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided as examples to demonstrate to the reader the present invention. As will be appreciated by one of skill in the art, the present invention may be embodied as a method, data processing system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code means embodied in the medium. Any suitable computer readable medium may be utilized including hard disks, CD-ROMs, optical storage devices, magnetic storage devices, or computer memory. FIGS. 6 a and 6 b show the basic elements in the present invention. FIG. 6 a shows an up arrow 605 and a down arrow 607 in addition to a scroll status bar 601 containing a scroll status indicator 603 which indicates that the information is scrolled approximately half way between the top and the bottom. The dark shading in both the up arrow 605 and the down arrow 607 indicates that there is room to scroll in both directions. The scroll status bar 601 can also be used as a fastpath to moving to specific locations within the data by selecting the indicator 603 within the bar and moving it to a desired location within the scroll status bar 601 . FIG. 6 b shows an example where the scroll status indicator 603 is at the top of the scroll status bar 601 therefore scrolling is only available in the downward direction. This is also indicated to the user by the greying of the upward arrow 609 . Referring to FIG. 7, the minimalist inline scroll control does not rely on the window paradigm. It is equally beneficial to an open desktop type of paradigm. The scroll control of the present invention is incorporated directly into the list of related objects (in the preferred embodiment this is a tree structure). FIG. 7 depicts a list of related items 701 , in this case a directory of a database, connected together as before with a dashed line. The scroll control 703 is superimposed on the dashed line so that the user can, by placing their pointing device on the scroll control and depressing a predefined button, scroll the list of related items in a given direction. The scroll control indicates that the top of the list is currently displayed (by having the upward arrow greyed) and there is room for scrolling in the downward direction. FIG. 5 shows a flow chart of the logic invoked when indicating a control arrow using the pointing device. First a check is made to determine if the pointing device is placed over a location which is active 501 . If not, no action is taken 503 . If the pointing device is over an active location for scroll control, the list in then moved in the indicated direction 505 . Checking is continued to determine if the pointing device is still activated, still over an active location and that there is still room to scroll in the indicated direction 507 , if so, scrolling is continued 505 otherwise the scrolling is stopped 509 . FIG. 8 provides additional information to the user in that the size of the scroll indicator 805 (the arrow) is proportional to the amount of information not yet displayed in the indicated direction. The arrow in FIG. 7 703 is much smaller than the arrow in FIG. 8 805 thereby indicating that there is more information yet to be displayed in the downward direction of the list of FIG. 8 than in the list of FIG. 7 . An additional enhancement is displayed in the status indicator 803 of FIG. 8 in that the status indicator depicts, proportionally, how much of the information is actually visible on the screen. The status indicator could also be used as a fastpath to the top or the bottom of the data should an implementor of the invention chose to trade additional screen clutter for this fastpath functionality, although the designers of the preferred embodiment have placed greater improtance on reducing screen clutter. While the preferred embodiment of the present invention depicts one use of the size of the arrow, there are several alternatives for using the size of the arrow contemplated by the inventors. These uses include, but are not limited to: 1) Indicating proportionally how much of the information is yet to be displayed in the indicated direction; and, 2) Exploding the active arrow as the pointing device approaches it so that it is easier to select using the pointing device. FIG. 9 depicts further enhancements to the present invention in that FIG. 9 shows a bidirectional arrow at the top 905 indicating that there is additional information available in both the upward and downward directions, and that arrow can be used to scroll in the upward direction (away from the dashed line). The bidirectional arrow at the bottom 903 of FIG. 9 indicates that there is information available in both the upward and downward directions. The arrow at the bottom 903 can be used to scroll in the downward direction. FIG. 2 depicts the logic of when to display the top scroll indicator and FIG. 3 depicts the logic of when to display the bottom scroll indicator. Both are very similar. In FIG. 2, first a check is made to determine if the top scroll is enabled 201 for the indicated list. If it is then a check is made to determine if the list is clipped at the top 203 which would indicate that there was room for scrolling in the upward direction and that an indicator should be activated at the top of the list. If the list is to be clipped at the top, since the top scroll is already enabled, then no further action is necessary 207 . If the list was not clipped at the top 203 , then the top scroller is disabled 205 since it had previously been enabled. If the top scroll was not enabled already 201 and the list was clipped at the top 209 then the top scroll indicator must be enabled 211 ; otherwise, if the list is not clipped at the top 209 no further action is necessary at this time 207 since the scroll indicator does not need to be displayed at this time. FIG. 3 is a flow chart similar to that of FIG. 2 for a bottom scroll bar. First a check is made to determine if the indicated list is clipped at the bottom 301 . If the list is clipped at the bottom, then a check is made to determine if the bottom scroller is already enabled 303 . If the bottom scroller is already enabled, then no action is taken 307 , otherwise the bottom scroller is enabled 305 . If, at 301 , the list was no longer clipped at the bottom (e.g. the bottom of the list had been reached) then a check is made to determine whether the bottom scroller is enabled 309 . If the bottom scroller is enabled then it is disabled 311 , otherwise no action is taken 307 . In the preferred embodiment, once a control has been indicated by the pointing device, that control remains in the same space on the screen, even if the branches of the tree upon which the scrolling action is being taken are indenting or moving to the left, until the indication has been released. This is best described by example as shown in FIGS. 10 a, 10 b and 10 c. If a downward indicator is selected such as the down arrow at 905 of FIG. 10 a, as the information scrolls downward, the control remains in the same position as shown in FIG. 10 b. Once the control is released, it once again becomes “inline” and returns to the information connectors as shown in FIG. 10 c. The scroll indicator of the present invention may be enhanced to have a variable speed scroll such that as the pointer indicator is depressed over the scroll indicator, the acceleration of the scrolling increases. The present invention, while expanding beyond the window paradigm of most current programs, is closely tied with the data contained within it and relies on relational properties within the data to be presented. Relational properties must exist within the data such as a list structure or a tree structure such that the scrolling can occur in an up and down or left and right manner. Another possible enhancement of the present invention is indicated by FIG. 4 . In order to further reduce clutter on the screen, the status indicator shown as item 601 of FIG. 6 a or item 803 of FIG. 8, would only be displayed when the pointer were within a certain proximity to a scroll control. If the pointer were not within the given proximity, then the status indicator would be hidden. To implement this, a check must first be made to determine whether the pointer was within a certain (either predetermined or customizable by the user) proximity to the scroller control 401 . If the pointer was within this proximity, then the status indicator is displayed 403 , otherwise the status indicator is hidden 405 .

A method and apparatus for inline scrolling of related objects in a computer desktop environment. This scrolling is accomplished by utilizing a pointing device to activate an indicator actually imbedded into the relational information for the data being presented. The inline scrolling is designed to reduce the amount of space required on a display device to convey information to the user.

BACKGROUND OF THE INVENTION In geological exploration or production activities it is frequently desired to utilize rotatable tool elements such as saws, drills and core sampling devices within a bore hole at a considerable distance beneath the surface. The rotatable tool element is usually carried within a sonde or downhole tool and is lowered into the bore hole on the end of a wireline having electrical conductors capable of transmitting electric power to the tool element. When such tool elements are operated in directions perpendicular to the axis of the bore hole and jam while in an extended position, a very serious problem exists. If the jam cannot be cleared and the cutting tool retracted, the downhole tool or sonde cannot be withdrawn from the bore hole without serious damage of destruction. To be effective a rotatable tool element must not only be rotated but must also be advanced into the material to be cut, drilled or sampled at a rate consistent with the ability of the tool to remove material. The rate of removal of the material varies with the hardness of the material and the condition of the cutting elements. Accordingly, an important object of this invention is to provide an hydraulic apparatus for providing both rotational and translational motion to a tool element, the rate of translational advance of the tool element being automatically maintained to be consistent with the rate of removal of material by the rotating tool element. When a rotatable tool becomes jammed it ceases to rotate and no longer serves to remove material or rotates so slowly as to be ineffective. When so jammed the tool is usually in an extended position and must be first retracted so that the downhole tool or sonde may be withdrawn from or otherwise moved in the bore hole. The following three modes of unjamming the tool are available: (1) Discontinue the supply of power for rotating the tool element and apply all available power to retraction thereof. (2) Continue to supply power for rotation of the tool element in the forward cutting direction and, additionally, supply power for retracting the tool element. (3) Supply power for rotation of the tool element in the reverse direction and, additionally, supply power for retracting the tool element. If one of the above modes of unjamming is ineffective either or both of the others can be effective. Moreover, in some cases repeated application of the several modes in different order can be effective. Accordingly, a second important object of this invention is to provide a tool element driving apparatus controllable from the surface for selectively applying any one of the above-described modes of unjamming to a tool disposed in a bore hole. Another object of this invention is to obtain maximum utilization of the conductors available in a wireline for powering the downhole tool with only a single conductor being required for control purposes in selection of the mode of operation. In a conventional seven conductor wireline this leaves six conductors available for supplying electrical power to the rotating tool and, when the significant IR drop involved when the downhole tool is suspended in very deep bore holes is taken into consideration, this feature is quite significant. Other objects and advantages of this invention will be apparent to those familiar with the art on reading the following description of the invention. SUMMARY OF THE INVENTION The hydraulic drive apparatus of this invention for use in downhole tools comprises: (a) an electric motor driven pump; (b) a positive displacement hydraulic motor connected by conduit means to the pump and adapted to be driven thereby; (c) a cutting tool element capable of rotational and translational movement and connected to the hydraulic motor so as to be rotationally drive thereby; (d) an hydraulic piston interconnected to the cutting tool element so as to impart translational movement thereto as the hydraulic piston is moved; and (e) conduit means interconnecting the outlet of said hydraulic motor to the hydraulic piston whereby translational advancing movement of the cutting tool element is imparted thereto at a rate which varies with the rate of rotational movement of the cutting tool. In a preferred embodiment means are provided at the surface for reversing the direction of the motor driven pump and a check valve means is provided to prevent fluid exiting from the pump from driving the hydraulic motor, the exiting fluid instead being conducted to the hydraulic piston to impart retracting movement thereto and to the cutting tool element. In order for the apparatus to be operatable within a deep bore hole a reservoir for hydraulic fluid is provided, and the fluid in this reservoir which is connected by conduit means to the two sides of the pump is subject to ambient bore hole pressure so that the hydraulic drive apparatus operates at an incremental pressure above bore hole pressure. To permit the supply of hydraulic fluid from the reservoir to the pump and to provide for adjustment of hydraulic fluid pressure within the apparatus to changes in bore hole pressure as the tool is raised or lowered, a pair of pilot operated check valves are provided in the conduits interconnecting the reservior with the two sides of the pump. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a preferred embodiment of the hydraulic drive apparatus of this invention; FIG. 2 is a diagram illustrating the direction of flow of hydraulic fluid through the apparatus in normal operation with the tool element both rotating and advancing; FIG. 3 is a diagram illustrating the direction of flow of hydraulic fluid through the apparatus when the pump is reversed, the tool element is not rotating and full power is applied to retract the tool element; FIG. 4 is a diagram illustrating the direction of flow of hydraulic fluid when the control valves are set so that the tool element is rotated in the same direction as in FIG. 2 and is simultaneously retracted; and FIG. 5 is a diagram illustrating the direction of flow of hydraulic fluid when the control valves are set so that the tool element is rotated in the opposite direction and is simultaneously retracted. In FIGS. 2-5 certain elements of the hydraulic apparatus have not been shown in order to more clearly show the hydraulic flow paths for driving the tool. DETAILED DESCRIPTION OF THE INVENTION The hydraulic drive system apparatus of a preferred embodiment of this invention is illustrated in FIG. 1. The major elements of the system include a positive displacement pump 10 adapted to be driven in either direction by an electric motor (not shown) an hydraulic motor 11 which is also positive displacement type, an hydraulic cylinder 12, and a reservoir 13. In addition to these elements the system includes interconnecting conduits and appropriate valves. Since the system of apparatus must be operable within a bore hole which can be filled with drilling mud or other fluid, the reservoir 13 is provided with a piston 14, or alternatively a diaphragm, which serves to separate the hydraulic fluid indicated at 15 from the bore hole fluid whose pressure is exerted against the piston 14 or diaphragm. Thus the hydraulic system operates at ambient bore hole pressure and the elements thereof need not be constructed in order to resist bore hole pressure which at a depth of around twenty thousand feet can be in the neighborhood of ten thousand pounds per square inch. Bore hole conditions also dictate the choice of the hydraulic fluid for temperatures ranging as high as about 250° F. can be encountered. The following fluids are satisfactory: Dow Corning Silicone Hydraulic Fluid Type 560 Autoline Hydraulic Oils Company E P Anti-Wear Hydraulic Oil Both sides of pump 10 are connected by conduits 16 and 17 through pilot operated check valves 20 and 21. Control conduits 22 and 23 for operating these valves are cross connected to opposite sides of the pump 10 in order to open the appropriate check valve on the suction sides of the pump 10 and supply any required make-up fluid from reservoir 13. Valves 20 and 21 also serve to adjust system pressure to bore hole pressure as bore hole pressure is varied, for example, when the tool is raised or lowered in the bore hole. Upon lowering the tool valves 20 and 21 serving as check valves open to admit fluid from the reservoir 13 to the system increasing its pressure to ambient bore hole pressure. Upon raising of the tool in the bore hole the pilot control through conduits 22 and 23 opens valves 20 and 21 when system pressure exceeds bore hole pressure to relieve system pressure. Hydraulic motor 11 is operatively connected to the rotary tool 11a which may be a drill, saw or coring cutter, for example, in any conventional manner. The hydraulic drive apparatus of this invention is particularly suited for supplying rotational and translational movement to the Apparatus for Drilling into the Sidewall of a Drill Hole described and claimed in U.S. Pat. application Ser. No. 051,485 filed June 25, 1979 by Alfred H. Jageler et al. and assigned to the assignee of the present application. The aforesaid Jageler el al. application is hereby incorporated herein by reference. Jageler et al. prefer to utilize two separate hydraulic systems for the tool element, one for rotation thereof and the other for advancing and retracting. In the present invention both rotational and translational movement of the cutting tool element 11a are provided by a single hydraulic system. To effect translational movement the rotary tool element (not shown) is also operatively connected to a piston 25 operating within hydraulic cylinder 12. Thus movement of piston 25 serves to advance or retract the cutting tool element. In order to protect the system when the piston 25 is fully advanced or fully retracted a pair of pressure relief valves 27 and 28 (FIG. 1) are provided. These valves are pilot controlled through control conduits 30 and 31 and are set so as to open the corresponding valve when a predetermined maximum differential pressure above bore hole pressure is encountered. Valves 27 and 28 are also operable to protect the system in the even for any reason the rotary tool cannot be advanced or retracted. The preferred system of apparatus also includes two conventional check valves 32 and 33, two throttling valves 34 and 35 and four function control valves A, B, C and D. The four function control valves can be preset at the surface or can be set from the surface by remote control to be in either open or closed position according to the function it is desired to perform. These valves can be solenoid operated, a conventional multiplexer being installed in the downhole tool to operate each valve in response to a predetermined signal transmitted down the wireline from the surface. Alternatively, the four valves may be formed in a single block having a rotating cylinder valve element setable in appropriate positions corresponding to the modes of operation. In the latter case solenoid means are provided for moving the valve element from one position to the next in response to electrical pulses sent down the wireline. It should be noted that only three valve setting positions are required since the valve settings in Mode I and Mode II operations described later can be the same. In addition to the control valve settings, control of the operational mode is determined by the direction the hydraulic pump 10 is driven. This pump is preferably driven by a direct current motor of such type that its direction of rotation can be changed by reversing the electrical connections to the power supply at the surface. In Mode I operation (see FIG. 2) the pump 10 is driven in such direction as to withdraw hydraulic fluid from conduit 17 forcing it under pressure into conduit 16. In Modes II, III and IV the pump runs in the opposite direction to force fluid into conduit 17. Control valve settings for the several modes and the resulting operations of the rotating tool element are as follows: Mode I--valves B and C closed A and D open. Tool rotates clockwise and advances. Mode II--valves B and C closed A and D may be opened or closed. Tool not rotating and retracts. Mode III--valves A and C closed B and D open. Tool rotates clockwise and retracts. Mode IV--valves B and D closed A and C open. Tool rotates counterclockwise and retracts. As used herein the relative terms advance and retract and clockwise and counterclockwise are employed merely to indicate opposite directions. As will be obvious to those familiar with the art depending upon gearing arrangements or linkages employed, opposite directions of motor rotation or piston movement can readily be achieved. The hydraulic fluid flow which is obtained in each of the four modes is indicated by arrows in FIGS. 2-5. For simplicity the reservoir 13 and its associated valves and the pressure relief valves have not been shown in these figures. The throttling valves 34 and 35 are utilized to control the relative flow of hydraulic fluid to cylinder 12 and accordingly the rate of movement of piston 25 to advance the rotating tool element, particularly when operating in Mode I whose flow pattern is illustrated in FIG. 2. As will be apparent when valve 35 is open wide and valve 34 is nearly closed a large proportion of fluid passing through the hydraulic motor 11 will pass through valve 35 and check valve 32 bypassing cylinder 12. Thus the rate of movement of piston 25 will be slow. Opening valve 34 and closing down valve 35 diverts more flow through conduit 40 and produces greater movement of piston 25. In practice valves 34 and 35 are preset when the downhole tool or sonde is at the surface for the desired relative rate of cutting tool advance. Tool advance, however, is also controlled by the rate of which positive displacement drive motor 11 turns. As this motor slows the fluid flow lessens and the throttling effects of valves 34 and 35 become minimal reducing or checking advance of the rotating tool. This feature tends to prevent stalling or jamming of the rotating tool which in turn speeds up as material is cut away with increasing fluid flow restoring the rate of advance of the tool to a higher level. In this manner the rate of advance of the cutting tool is automatically adjusted to the cutting speed of the rotating tool element. Normal operation of the hydraulic system of this invention is conducted in Mode I and upon completion of a satisfactory cutting operation the polarity of the leads in the wireline connected to the electric motor in the sonde is reversed to reverse the motor and the direction of pump 10. The fluid flow pattern is then as shown in FIG. 3 and Mode II operation is achieved. Motor 11 is not driven but piston 25 is moved by fluid entering cylinder 12 through valve 34 to retract the cutting tool. In this Mode II valves A and D can be open or closed for fluid leaving cylinder 12 can readily pass through check valve and conduit 41 back to the pump 10. In this mode it should be noted that the full power of pump 10 is exerted upon the piston 25. In Mode III operation the fluid flow is as shown in FIG. 4 turning the motor 11 clockwise while retracting the tool. In Mode IV operation the fluid flow is as shown in FIG. 5, the tool retracting and the motor turning counterclockwise. As will be appreciated by those familiar with the art a means of freeing up a rotary cutting tool which is jammed and will not turn is provided by adjusting the control valves from the surface to first apply torque on the motor 10 in one direction and then in the other direction by alternately operating in Mode III and Mode IV. In this manner force to retract the tool is applied in both modes. A shift to Mode II subsequent to a number of cycles between Modes III and IV can free a cutting tool otherwise impossible to move. The kind of cutting tool employed in some cases governs the mode of operation which can be employed. Cutters which are diamond faced can usually be driven in either direction without damage but cutters having edges such as are employed in ripsaws should usually not be driven backwards or tool damage will result. On the other hand tool damage is highly preferred over having to leave a sonde in a bore hole, and reverse driving can in some cases free up the tool so that it may be retracted into the sonde and withdrawn from the bore hole. A fifth mode of operation can be achieved, if desired, by setting the function control valves in the positions indicated for Mode IV and reversing the direction of the pump 10. In this fifth mode the tool is driven clockwise but no force is applied to move the piston 25. Alternating between Mode IV and this fifth mode can be useful in some situations with particular cutting tools and is convenient since, as in Modes I and II no change in the function control valves need be made, only reversal of the direction of pump 10. Thus for Modes I and II operations and for Modes IV and V operation, the function control valves can be preset at the surface. Alternatively the apparatus need not have function control valves at all if appropriately piped. A preferred embodiment of the invention has been described above however various changes and modifications such as will present themselves to those familiar with the art may be made without departing from the spirit of the invention whose scope is defined by the following claims.

An hydraulic drive apparatus for use in downhole tools is described. The apparatus provides rotational and translational movement to a cutting tool element disposed in a downhole tool or sonde automatically adjusting advancing motion of the cutting tool to the rate of rotational movement or cutting. The apparatus is controllable from the surface through a wireline and is capable of operating in various modes to facilitate unjamming.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in general to a radio transmitting and receiving apparatus, and more particularly to a transmitting and receiving apparatus for a headphone of the digital type. 2. Description of the Prior Art With reference to FIG. 1, there is shown a block diagram of a conventional transmitting apparatus for a headphone of the analog type. The illustrated transmitting apparatus comprises a first amplifying circuit 33 including amplifiers 31 and 32 for amplifying respectively a left sound signal L/S and a right sound signal R/S from a headphone output of a television set or a radio set by a predetermined amplification degree, a frequency modulating circuit 35 including frequency modulators 35a and 35b for frequency-modulating respective output signals from the amplifiers 31 and 32 in the first amplifying circuit 33, a first band-pass filtering circuit 36 including band-pass filters 36a and 36b for filtering respective output signals from the frequency modulators 35a and 35b in the frequency modulating circuit 35 to pass only frequency components of desired band width, and a transmitting circuit 37 including a transistor Q4 and a light-emitting diode D5, for transmitting output signals from the band-pass filters 36a and 36b in the first band-pas filtering circuit 36 with infrared rays carrying the signals. With reference to FIG. 2, there is shown a block diagram of a conventional receiving apparatus for a headphone of the analog type. The illustrated transmitting apparatus comprises a circuit 38 including a transistor Q5 and a light-receiving diode D8, for receiving light signals transmitted from the transmitting circuit 37 in the transmitting apparatus and amplifying the received signals by a predetermined amplification degree, a second band-pass filtering circuit 41 including band-pass filters 39 and 40 for filtering respective output signals from the receiving circuit 38 to pass only frequency components of desired band width, a demodulating circuit 44 including demodulators 42 and 43 for demodulating respective output signals from the band-pass filters 39 and 40 in the second band-pass filtering circuit 41, a second amplifying circuit 47 including amplifiers 45 and 46 for amplifying respective output signals from the demodulators 42 and 43 in the demodulating circuit 44 by a predetermined amplification degree, and a sound output circuit 52 including a switch SW1, resistors R3 and R4, power amplifiers 48 and 49 and headphone speakers 50 and 52, for outputting analog sound signals from the amplifiers 45 and 46 in the second amplifying circuit 47 as sound signals. The operation of the conventional transmitting and receiving apparatus for a headphone of the analog type which is constructed as mentioned above will be described. Generally, the left sound signal L/S and the right sound signal R/S through the headphone output of the television set or radio set are weak in level. For this reason, in the transmitting apparatus, the left sound signal L/S and the right sound signal R/S are amplified by a predetermined amplification degree, respectively, by the amplifiers 31 and 32 in the first amplifying circuit 33. These amplified signals from the amplifiers 31 and 32 are frequency-modulated, respectively, by the frequency modulators 35a and 35b in the frequency-modulating circuit 35 and the frequency-modulated signals from the frequency modulators 35a and 35b are then applied to the band-pass filters 36a and 36b in the first band-pass filtering circuit 36. Upon receiving the frequency-modulated signals from the frequency modulators 35a and 35b, the band-pass filters 36a and 36b filter, respectively, the received signals to pass only frequency components of desired band width. Then, the output signals from the band-pass filters 36a and 36b are transmitted to the light-receiving diode D8 in the receiving circuit 38 in the receiving apparatus through the light-emitting diode D5 in the transmitting circuit 37. At this time, a diode D7 emits a light signal which is indicative of signal transmission. An LED driver 34 functions to drive the diode D7. In the receiving apparatus, the signals inputted through the light-receiving diode D8 in the receiving circuit 38 are amplified, respectively, by a predetermined amplification degree by the transistor Q5 in the receiving circuit 38. Then, the band-pass filters 39 and 40 in the second band-pass filtering circuit 41 filter the amplified signals, respectively, from the receiving circuit 38 to pass only frequency components of desired band width. In the demodulating circuit 44, the demodulators 42 and 43 demodulate the output signals from the band-pass filters 39 and 40, respectively. Then, the demodulated signals are amplified by the amplifiers 45 and 46 in the second amplifying circuit 47. In the second amplifying circuit 47, the resistor R1 and the capacitor C1, and the resistor R2 and the capacitor C2 operate, respectively, as low-pass filters. In the sound output circuit 52, the amplified left and right signals from the amplifiers 45 and 46 are inputted to the power amplifiers 48 and 49 in mono or stereo in accordance with a selection of the switch SW1. Upon receiving the amplified left and right signals from the amplifiers 45 and 46, the power amplifiers 48 and 49 amplify the received signals, respectively, by a given amount and output the amplified signals as sound signals through the headphone speakers 50 and 51. However, the conventional transmitting and receiving apparatus for a headphone of the analog type has a disadvantage, in that the apparatus is susceptible to noise. For this reason, when the apparatus transmits the signals utilizing an infrared ray, a malfunction thereof may occur according to a direction of the TV set or radio set. Also, there may occur interference due to an infrared ray signal from other systems. SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above problem, and it is an object of the present invention to provide transmitting and receiving apparatus for a headphone of the digital type, which processes audio signals from a television set or radio set in a frequency modulation (FM) manner, transmits the FM processed audio signals by wireless in a digital transmission manner and receives the transmitted signals by wireless in a digital reception manner. In accordance with one aspect of the present invention, there is provided a transmitting and receiving apparatus for a headphone, comprising: transmitting means for demodulating a received broadcast audio signal into a digital signal, frequency-modulating the digital signal in accordance with predetermined carrier frequencies corresponding to contents of channel data, and transmitting the frequency-modulated digital signal with an infrared ray carrying the signal; and receiving means for receiving the signal transmitted from said transmitting means, demodulating the received signal into a digital signal, converting the demodulated digital signal into an analog signal, and transducing/outputting the analog signal as sound. In accordance with another aspect of the present invention, there is provided a transmitter for a headphone, comprising: demodulating means for demodulating a received broadcast audio signal into a digital signal, dividing the digital signal into three-channel data; namely, sound data, data for synchronization of the sound data, and data indicative of whether the sound data is in mono or in stereo; modulating means for frequency-modulating the three-channel data from said demodulating means in accordance with predetermined carrier frequencies corresponding to the three-channel data; and transmitting means for transmitting output data from said modulating means externally. In accordance with still another aspect of the present invention, there is provided a receiver for a headphone, comprising: data receiving means for receiving data transmitted from the transmitting means; envelope detecting means for dividing the data received by said data receiving means into data by channel and detecting envelopes of respective channel data; and output means for outputting an output signal from said envelope detecting means as an analog sound signal. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a block diagram of conventional transmitting apparatus for a headphone of the analog type; FIG. 2 is a block diagram of conventional receiving apparatus for a headphone of the analog type; FIG. 3 is a block diagram of transmitting apparatus for a headphone of the digital type in accordance with the present invention; FIG. 4 is a block diagram of receiving apparatus for the headphone of the digital type in accordance with the present invention; FIG. 5 is a block diagram of a D/A converting circuit in the receiving apparatus in FIG. 4. FIGS. 6a through 6d are waveform diagrams of digital signals in accordance with the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First, a construction of transmitting and receiving apparatus for a headphone of the digital type in accordance with the present invention will be described with reference to FIGS. 3 through 5. With reference to FIG. 3, there is shown a block diagram of a transmitting apparatus for a headphone of the digital type in accordance with the present invention. As shown in this drawing, the transmitting apparatus of the present invention comprises: a demodulating circuit 21 including a quadrature phase shift keying (QPSK) demodulator 1 and a sound demodulator 2, for receiving a broadcast sound signal transmitted in a QPSK transmission manner, demodulating the received broadcast signal into a digital signal and dividing the digital signal three-channel data, a first sound output circuit 22 including a D/A converter 3, a first amplifier 4 and a speaker 5, respectively, for converting the three-channel data from the demodulating circuit 21 into an analog signal, amplifying the analog signal by a predetermined amplification degree and outputting the amplified signal through the speaker 5; a frequency modulating circuit 23 including carrier modulators 6a through 6c and frequency oscillators F1 through F3, for frequency-modulating, respectively, the three-channel data from the demodulating circuit 21; an amplifying circuit 24 including amplifiers 7a through 7c, for amplifying output signals from the frequency modulating circuit 23, respectively, to a predetermined transmission level; and a transmitting circuit 25 including infrared transmitters 8a through 8c having transistors Q1 to Q3 and light-emitting diodes D1 to D3, respectively, for transmitting output signals from the amplifying circuit 24 with infrared rays carrying the signals. With reference to FIG. 4, there is shown a block diagram of a receiving apparatus for a headphone of the digital type in accordance with the present invention. As shown in this drawing, the receiving apparatus of the present invention comprises a receiving circuit 26 including a light-receiving diode D4 and a preamplifier 9, for receiving signals transmitted from the transmitting circuit 25 in the transmitting apparatus and amplifying the received signals by a predetermined amount, a band-pass filtering circuit 27 including band-pass filters 10a through 10c for filtering, respectively, output signals from the receiving circuit 26 to pass only frequency components of desired band width corresponding to respective channel data, an envelope detecting circuit 28 including envelope detectors 11a through 11c, for detecting envelopes of respective channel data from output signals from the band-pass filtering circuit 27, a D/A converting circuit 12 for converting output signals from the envelope detecting circuit 28 into analog sound signals, and a second sound output circuit 29 including power amplifiers 13a and 13b and speakers 14a and 14b, for amplifying analog signals from the D/A converting circuit 12, respectively, by a predetermined amount and outputting the amplified signals, respectively, through the speakers 14a and 14b. With reference to FIG. 5, there is shown a block diagram of the D/A converting circuit 12 in the receiving apparatus. The D/A converting circuit 12 includes a timing controller 15 for controlling timing of an output signal from the envelope detecting circuit 28, a digital data latch 16 for latching an output signal from the timing controller 15, a right channel data latch 17 for latching right channel data of an output signal from the digital data latch 16, a left channel data latch 18 for latching left channel data of the output signal from the digital data latch 16, a D/A converter 12a for converting digital data from the left channel data latch 18 into the left analog sound signal, and a D/A converter 12b for converting digital data from the right channel data latch 17 into the right analog sound signal. Now, the operation of the transmitting and receiving apparatus for a headphone of the digital type with the above-mentioned construction in accordance with the present invention will be described in detail with reference to FIG. 6. First, when the television set receives a digital audio signal SO transmitted in the QPSK transmission manner (digital transmission manner) from a broadcasting station, the digital audio signal SO is demodulated into a digital signal by the QPSK demodulator 1 in the demodulating circuit 21. The digital signal from the QPSK demodulator 1 is demodulated into digital sound data S1, timing data S2 and digital channel information data S3 by the sound demodulator 2 in the demodulating circuit 21. In first sound output circuit 22, the D/A converter 3 converts the digital sound data S1, timing data S2 and digital channel information data S3 from the demodulating circuit 21 into an analog signal. Then, the analog signal from the D/A converter 3 is amplified to an aural sound level by the first amplifier 4 and the amplified signal is outputted as a sound signal through the speaker 5 in the television set. As shown in FIGS. 6a through 6c, the digital sound data S1 are sound data values transmitted from the broadcasting station, the timing data S2 is clock data for synchronization of the digital sound data S1, and the digital channel information data S3 indicates whether the digital sound data S1 is a mono signal or a stereo signal. Also, the digital sound data S1, timing data S2 and digital channel information data S3 from the demodulating circuit 21 are inputted to the frequency modulating circuit 23. In the frequency modulating circuit 23, the digital sound data S1, timing data S2 and digital channel information data S3 are frequency-modulated, respectively, by carrier modulators 6a through 6c in accordance with carrier frequencies from the frequency oscillators F1 through F3, as shown in FIG. 6d. Typically, in the carrier modulators, the user can directly adjust the frequency oscillators F1 through F3 to vary the modulating frequencies. For this reason, there can be prevented interference due to infrared ray signals from other systems. Next, the digital sound data S1, timing data S2 and digital channel information data S3 from the frequency modulating circuit 23 are amplified, respectively, to a predetermined transmission level by the amplifiers 7a through 7c in the amplifying circuit 24. Then, the amplified data from the amplifying circuit 24 is transmitted to the receiving apparatus with infrared rays carrying the data by the infrared transmitters 8a through 8c in the transmitting circuit 25. In the receiving apparatus, the receiving circuit 26 receives the digital sound data S1, timing data S2 and digital channel information data S3 transmitted from the transmitting circuit 25 in the transmitting apparatus by the light-receiving diode D4 therein and amplifies the received data by a predetermined amount by the preamplifier 9 therein. The amplified signal from the receiving circuit 26 is applied to the band-pass filtering circuit 27. Upon receiving the amplified signal from the receiving circuit 26, the band-pass filters 10a through 10c in the band-pass filtering circuit 27 filter, respectively, the amplified signal from the receiving circuit 26 to pass only frequency components of desired band width corresponding to the digital sound data S1, timing data S2 and digital channel information data S3. Then, the envelope detectors 11a through 11c in the envelope detecting circuit 28 detect envelopes of respective corresponding data, i.e., the digital sound data S1, timing data S2 and digital channel information data S3 from the output signals from the band-pass filtering circuit 27 and output the detected envelopes of respective data to the D/A converting circuit 12. The D/A converting circuit 12 converts the detected envelopes of the digital sound data S1, timing data S2 and digital channel information data S3 from the envelope detecting circuit 28 into analog sound signals and outputs the analog sound signals to the second sound output circuit 29. Then, in the second aural sound output circuit 29, the analog sound signals from the D/A converter 12 are amplified, respectively, to a sound level by the power amplifiers 13a and 13b and the amplified signals are outputted as sound signals through the speakers 14a and 14b. Referring again to FIG. 5, upon receiving the digital sound data S1 and the timing data S2, the timing controller 15 in the D/A converter 12 controls a timing of the digital sound data S1 synchronously with the timing data S2. Then, the digital sound data S1 from the timing controller 15 is latched into the digital data latch 16. The digital sound data S1 in the digital data latch 16 is then latched into the left channel data latch 18 or the right channel data latch 17 or both of them in accordance with a content of the digital channel information data S3. Then, the D/A converter 12a converts the digital data from the left channel data latch 18 into the left analog sound signal S4 and the D/A converter 12b converts the digital data from the right channel data latch 17 into the right analog sound signal S5. These analog sound signals S4 and S5 are applied to the second sound output circuit 29. As hereinbefore described, in accordance with the present invention, there is provided a transmitting and receiving apparatus for a headphone of the digital type, which processes audio signals from the television set or radio set in a frequency modulation (FM) manner, transmits the FM processed signals by wireless in a digital transmission manner and receives the signals by wireless in a digital reception manner. Therefore, the user can listen to noiseless sound through a headphone. Also, since the user can directly adjust the modulating frequencies, there can be prevented an interference due to infrared ray signals from other systems. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

A transmitter and receiving apparatus from a headphone, comprising a demodulating circuit for demodulating a received broadcasting signal into multi-channel data, a modulating circuit for frequency-modulating each channel of the multi-channel data with a different carrier frequency, said carrier frequencies being selectable by the user to avoid local interference, and a transmitting circuit for transmitting output data from said modulating circuit externally. There is also provided a receiver for a radio headphone, comprising a data receiving circuit for receiving data transmitted from an external transmitting circuit, a demodulator for dividing the data received by said data receiving circuit into separate frequency channels, an envelope detecting circuit for detecting envelopes of respective channel data, and an output circuit for outputting an output signal from said envelope detecting circuit as an analog sound signal so as to allow a user to listen to noiseless sound through a headphone.

FIELD OF THE INVENTION [0001] The invention pertains to head trackers. More particularly, the invention pertains to optical head trackers which are relatively inexpensive and have relatively minimal set-up time. BACKGROUND OF THE INVENTION [0002] It has been known to use head trackers in simulators which are used in various types of equipment, such as flight simulators, vehicular simulators such as armored units or other types of land vehicles as well as water born vehicles. Many of the known types of head trackers provide multiple degrees of information, such as six degree of freedom in position and orientation information so that appropriate views or displays can be activated only as needed. Known multiple degree of head trackers have been based on various different technologies. These have included ultrasound, optical, inertial, or magnetic. [0003] While known head trackers are effective for their intended purpose, they are often expensive and require extensive set-up times. Additionally, known head trackers often require substantial software interaction to address the various signals coming therefrom. This can include dedicating resources to carry out extensive plotting. [0004] Certain types of simulations require information for only a single degree of freedom, for example, in the azimuthal direction. For example, armoured simulators, such as armored wheeled or tracked vehicles present to the vehicle commander a plurality of spaced-apart displays simulating cupola or tank turret periscopes which face different directions. In these instances, the vehicle commander would only need to rotate his or her head about a substantially fixed vertical axis to view displays presented at several different angles. Viewing directions could include, for example, straight ahead, 20 to 22 degrees to the right, 45 degrees to the right, and similar angles to the left. [0005] Thus, there continues to be a need for head trackers which provide more limited amounts of information, corresponding to fewer degrees of freedom, than heretofore known. Preferably, such head trackers could be implemented more cost effectively than multiple degree of freedom head trackers of known types. Additionally, it would be preferable if set-up times could be reduced so that the speed of training or conducting exercises can be increased. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 is a top plan view of an apparatus in accordance with the present invention; [0007] FIG. 2 is a side elevational view of the apparatus of FIG. 1 ; and [0008] FIG. 3 is a block diagram of a system in accordance with the invention. DETAILED DESCRIPTION OF THE EMBODIMENTS [0009] While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiment illustrated. [0010] This invention provides a simple, low-cost means for determining a single-plane angular orientation of an object, such as a person's helmet in a simulator. This is accomplished in a disclosed embodiment by the use of fixed infra-red (IR) light sources spaced circumferentially around the helmet, pointing at the helmet. Reflective material placed at one point on the helmet. A detector is located near each light source to detect the reflected infra-red beam. [0011] Some of the advantages of this embodiment of this invention are that they do not require complex equipment configurations. They are very low cost. Data processing does not require detailed plotting as many trackers do. They do not cause electromagnetic interference in displays and electronics as magnetic trackers sometimes do. Conventional head trackers cost several thousand dollars for the hardware. Embodiments of this invention can be implemented for no more than a few hundred dollars. Set-up time for conventional head trackers can be several man months. For embodiments of this invention it is a matter of a few man days. [0012] One embodiment of this invention uses several similar infra-red (IR) sources angularly displaced around the helmet position and directed toward the geometric center of the cupola, where the helmet is normally centered. The helmet has a retroreflective material, which could be a retro-reflective tape, attached to it so that each IR source illuminates the retro-reflector, in turn, as the head is rotated about a vertical axis. [0013] IR detectors, each placed close to a respective IR source, detect the retro-reflected light only from the respective IR source, and only when the retro-reflective material is within the IR beam. In this way the angular position of the helmet is determined, well enough to determine which of the several discrete displays is being viewed by an operator. In this way display generating capacity can be conserved by only providing imagery to those displays viewable by the operator or trainee. [0014] FIGS. 1 and 2 are a top plan view and a side elevational view, respectively, of an exemplary vehicular simulator, such as a simulator for an armored vehicle which might have a turret or a cupola. Periphery views in the turret or cupola are in part simulated by a plurality of displays or display units 14 - 1 , - 2 , - 3 , - 4 , - 5 . The displays 14 - 1 . . . - 5 are dispersed around an axis of rotation A. [0015] The axis of rotation A corresponds to an axis of rotation about which a human operator H with a nose N rotates his/her head from a straight ahead rotation to the right or left, depending on the requirements of the training exercise or the simulation. A display generator, best seen in FIG. 3 , energizes some, but not necessarily all, of the displays 14 - 1 . . . - n depending on the position of the nose N of the operator H. [0016] A head positioning system in accordance with the invention is in part indicated generally at 20 and can be incorporated into the simulator 10 as described subsequently. The system 20 incorporates a plurality of sources 22 - 1 , 22 - 2 . . . 22 - 5 of beams of radiant energy, of a selected frequency, such as infra-red or visible red. The sources, such as 22 - 1 transmit a respective beam of radiant energy 24 - 1 . . . 24 - 5 toward the axis A. The operator or trainee H might be wearing a helmet which carries a reflective material indicated generally at 30 thereon. The material 30 is selected such that it will reflect radiant energy at the frequency of the respective source or sources 22 - 1 . . . - n. [0017] A respective sensor, 26 - 1 . . . - 5 is associated with each of the sources 22 - i. Each of the sensors 26 - i is responsive to incoming or sensed radiant energy, such as radiant energy 24 - 3 R which has been reflected off of surface 30 and as result, is incident on sensor 26 - 3 . [0018] As the trainee or operator H rotates his/her head about the axis A, the reflective surface 30 is arcuately moved about the axis A and can reflect a different beam of incident radiant energy, for example, beam 24 - 1 which would then be reflected back to sensor 26 - 1 in the event that the nose N of the trainee or operator has been rotated so as to be directed toward the display 14 - 5 . The source/sensor combinations 22 - 1 , 26 - 1 provide signals to a related control system, which could include a programmable processor, best seen in FIG. 3 , indicative of an azimuthal parameter indicated in phantom on FIG. 1 by angle A 1 . [0019] It will be understood that neither the exact number or type of sources of radiant energy or sensors are limitations of the present invention. The number to be used would be determined by the type of simulator as would be understood by those of skill in the art. Similarly, the frequency of the transmitted beams of radiant energy is not a limitation of the present invention. [0020] The exact configuration of a source/sensor combination is not a limitation of the present invention. Sources and respective sensors can be carried in a common housing. Alternately, separate housings can be used. The configuration of source and sensor can be coaxial if desired. Other combinations and orientations are possible and all come within the spirit and scope of the present invention. [0021] FIG. 3 illustrates system 34 in accordance with the invention. The plurality of sources 22 - 1 . . . - n is driven from control circuitry, which could include a programmed processor, 36 . The control circuitry 36 provides overall control functionality to carry out the desired simulation or training exercise. [0022] Sensors 26 - 1 . . . - n are coupled to control circuitry 36 . The sources 22 - 1 generate respective beams of radiant energy 24 - 1 . As indicated above, the beams of radiant energy can be of various frequencies, infra-red or visible. Alternately, it should be understood that the sources 22 - 1 . . . - n need not emit the same frequencies. The sources 22 - 1 . . . - n could in fact emit different respective frequencies, as would be understood by those of skill in the art. [0023] The sensors 26 - 1 . . . - n respond to received incident energy of the appropriate frequency, such as respective incident energy 24 - i R. In accordance with the embodiment of FIGS. 1 and 2 , only one of the sensors will receive reflected signal depending on the position of reflective element 30 . It will be understood that other embodiments of the invention are possible. These include a plurality of reflective elements spaced around the helmet of the trainee or operator H. The plurality of reflective elements would generate a plurality of reflected beams, similar to 24 - i R, but a multiplicity thereof, directed toward respective sensors such as sensors 26 - 1 , - 2 , . . . - n. In such instances, the control computer 36 will received a plurality of signals from the sensors 26 - 1 . . . - n indicative of position of the head of the operator H. All such variations come within the spirit and scope of the present invention. [0024] Control circuitry 36 also provides feedback azimuthal signals to image generator 38 . Generator 38 in turn drives respective members of the plurality displays 14 - 1 . . . 14 - n with signals to present an appropriate image on those display units which are individual fields of vision of the trainee or operator H. For example, if the operator or trainee H is looking straight ahead, as in FIG. 1 , displays 14 - 2 , - 3 and - 4 could be activated with the appropriate display as those would be within the expected field of vision of the operator or trainee H. Displays 14 - 1 , - 5 could be displaying an image if desired but the image would not necessarily be the current imagery as seen in displays 14 - 2 , - 3 and - 4 . With other orientations of the nose N of the trainee or operator H, other combinations of display units could be energized with the current appropriate display segment [0025] From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.

A head tracking system combines a plurality of sources of radiant energy, a plurality of sensors and at least one reflective element. As the reflective element moves, various radiant energy beams become incident thereon. The incident beams are reflected to respective sensors thereby providing head position signals.

BACKGROUND OF THE INVENTION 1. Technical Field of the Invention The present invention relates to an acoustic signal output apparatus that corrects a signal detected from a vibration of a stringed instrument and outputs an acoustic signal, a filter characteristics determination apparatus for an acoustic correction filter used in the acoustic signal output apparatus, and methods of designing and forming the acoustic correction filter. 2. Prior Art Conventionally, there is used an electric stringed instrument simulating a natural stringed instrument such as a violin and the like. The electric stringed instrument uses a pickup to detect a string vibration and amplifies the detected signal for output of sound. Such an electric stringed instrument enables a so-called mute performance in which a detected signal is output to a headphone and the like. The electric stringed instrument is very useful as a musical training tool used for practice in a situation where it is not permitted to generate a loud musical sound. However, the electric stringed instrument does not have an acoustic structure such as a resonance body that is essential to the natural stringed instrument. Accordingly, the electric stringed instrument differs from the natural stringed instrument in performance feelings and the like. There is available a method of enabling an instrumental performance that does not generate a loud musical sound while maintaining performance feelings of the natural stringed instrument. More specifically, a mute member is attached to a bridge member of the natural stringed instrument to suppress transmission of the string vibration to the resonance body and the like while providing a dummy sound instead of the natural sound. PROBLEMS TO BE SOLVED BY THE INVENTION According to such technique of attaching the mute member, however, a player or the like cannot hear the true musical sound generated during his or her performance. As a solution, a sophisticated instrument has been designed to use a pickup to detect vibration of a bridge member or the like arrested by the mute member, and amplify and output the detected signal to headphones and the like. This technique realizes the performance without generating a loud sound while maintaining performance feelings of natural musical instruments. However, when the electric signal is detected from the vibrated bridge of the stringed instrument arrested by the mute member and is amplified for output, the quality of the musical sound heard from headphones and the like degrades in comparison with natural musical sound generated from the resonance body or the like with no mute member attached. SUMMARY OF THE INVENTION The present invention has been made in consideration of the foregoing. It is therefore an object of the present invention to provide an acoustic signal output apparatus, methods of designing and forming an acoustic correction filter, and a filter characteristics determination apparatus capable of outputting a realistic musical sound based on a signal obtained from string vibration despite attachment of a vibration suppression means such as a mute member. In order to solve the above-mentioned problems, there is provided a method of designing an acoustic correction filter applicable to a stringed instrument composed of a string member operable to undergo a vibration, a support member for supporting the string member, a body member responsive to the vibration transmitted through the support member for generating a natural sound and a mute attachment for muting the natural sound. The acoustic correction filter is operable when the natural sound is muted by the mute attachment for filtering a signal derived from the vibration so as to create an artificial sound instead of the muted natural sound. The inventive method comprises the steps of acquiring a first sample signal from the vibration under a mute state where the transmittance of the vibration to the body member is suppressed by the mute attachment to mute the natural sound, acquiring a second sample signal from the vibration under a free state where the body member is allowed to generate the natural sound in response to the vibration transmitted to the body member, extracting a difference between the acquired first sample signal and the acquired second sample signal, and determining a correction characteristic of the acoustic correction filter based on the extracted difference such that the acoustic correction filter can filter the signal in accordance with the determined correction characteristic so as to create the artificial sound comparable to the natural sound. Practically, the step of extracting comprises deriving a first amplitude profile of the first sample signal along a common frequency axis, deriving a second amplitude profile of the second sample signal along the common frequency axis, and extracting the difference between the first sample signal and the second sample signal in terms of an amplitude difference between the first amplitude profile and the second amplitude profile along the common frequency axis, and the step of determining determines the correction characteristic of the acoustic correction filter based on the extracted amplitude difference. Expediently, the step of determining further comprises inverting a frequency characteristic of the second sample signal, collecting an acoustic signal corresponding to the natural sound from a particular location under the free state where the natural sound is generated by the body member of the stringed instrument, and further determining the correction characteristic of the acoustic correction filter based on the inverted frequency characteristic of the second sample signal and a characteristic of the collected acoustic signal, such that the acoustic correction filter can filter the signal in accordance with the further determined correction characteristic so as to create the artificial sound as if heard at the particular location. The inventive method makes it possible to design an acoustic correction filter having a characteristic that corrects or compensates for a difference between the first sample signal detected from vibration of the string while using the given suppression means such as the mute attachment to suppress vibration of the support member and the second sample signal detected from the vibration of the string while not using the given suppression means to suppress vibration. Accordingly, when the acoustic correction filter designed by the inventive method is used to filter a signal that is detected while using the suppression means to suppress vibration, it is possible to output an artificial or synthetic sound having almost the same characteristic as that of a natural sound generated while not using the suppression means to suppress vibration. Even if vibration of the bridge or the like is suppressed or arrested by the mute attachment on the stringed instrument for mute performance, an original signal can be obtained from vibration of a string. When the obtained signal is made to pass through the acoustic correction filter designed as mentioned above, the original signal can be converted into a modified signal having almost the same characteristic as that of a signal detected under the free state where no vibration is suppressed. In another aspect of the invention, there is provided a method of forming an acoustic correction filter applicable to a stringed instrument composed of a string member operable to undergo a vibration, a support member for supporting the string member, a body member responsive to the vibration transmitted through the support member for generating a natural sound and a mute attachment for muting the natural sound. The acoustic correction filter is operable when the natural sound is muted by the mute attachment for filtering a signal derived from the vibration so as to create an artificial sound instead of the muted natural sound. The inventive method comprises the steps of acquiring a first sample signal from the vibration under a mute state where the transmittance of the vibration to the body member is suppressed by the mute attachment to mute the natural sound, acquiring a second sample signal from the vibration under a free state where the body member is allowed to generate the natural sound in response to the vibration transmitted to the body member, extracting a difference between the acquired first sample signal and the acquired second sample signal, determining a correction characteristic of the acoustic correction filter based on the extracted difference, and forming the acoustic correction filter in accordance with the determined correction characteristic such that the acoustic correction filter can filter the signal so as to create the artificial sound comparable to the natural sound. In a further aspect of the invention, there is provided an apparatus for determining a correction characteristic of an acoustic correction filter applicable to a stringed instrument composed of a string member operable to undergo a vibration, a support member for supporting the string member, a body member responsive to the vibration transmitted through the support member for generating a natural sound and a mute attachment for muting the natural sound. The acoustic correction filter is operable when the natural sound is muted by the mute attachment for filtering a signal derived from the vibration so as to create an artificial sound instead of the muted natural sound. The inventive apparatus comprises an input section that inputs a first sample signal derived from the vibration under a mute state where the transmittance of the vibration to the body member is suppressed by the mute attachment to mute the natural sound, and inputs a second sample signal derived from the vibration under a free state where the body member is allowed to generate the natural sound in response to the vibration transmitted to the body member, an extracting section that extracts a difference between the inputted first sample signal and the inputted second sample signal, and a determining section that determines the correction characteristic of the acoustic correction filter based on the extracted difference such that the acoustic correction filter can filter the signal in accordance with the determined correction characteristic so as to create the artificial sound comparable to the natural sound. In a still further aspect of the invention, there is provided an apparatus for outputting an acoustic signal applicable to a stringed instrument composed of a string member operable to undergo a vibration, a support member for supporting the string member, a body member responsive to the vibration transmitted through the support member for generating a natural sound and a mute attachment for muting the natural sound. The inventive apparatus is operable when the natural sound is muted by the mute attachment for outputting the acoustic signal representative of an artificial sound instead of the muted natural sound. The inventive apparatus comprises an acquiring section that acquires a first sample signal from the vibration under a mute state where the transmittance of the vibration to the body member is suppressed by the mute attachment to mute the natural sound, and acquires a second sample signal from the vibration under a free state where the body member is allowed to generate the natural sound in response to the vibration transmitted to the body member, an extracting section that extracts a difference between the acquired first sample signal and the acquired second sample signal, a determining section operable based on the extracted difference to determine a correction characteristic for a performance signal inputted by performing a stringed instrument under the mute state, and an acoustic filter section having a filter that filters the performance signal in accordance with the determined correction characteristic so as to create the acoustic signal representative of the artificial sound comparable to the natural sound. Optionally, the stringed instrument has a plurality of mute attachments that can be selectably attached to the stringed instrument to mute the natural sound in different manners, and the determining section determines a plurality of correction characteristics in correspondence to the plurality of the mute attachments. In such a case, the inventive apparatus further comprises a selecting section that selects one of the plurality of the correction characteristics for enabling the filter to create the acoustic signal representative of the artificial sound under the mute state held by the mute attachment corresponding to the selected correction characteristic. Practically, the determining section includes an inverting section for inverting a frequency characteristic of the second sample signal and a collecting section for collecting an acoustic signal corresponding to the natural sound from a particular location under the free state where the natural sound is generated by the body member of the stringed instrument, thereby further determining an additional correction characteristic based on the inverted frequency characteristic of the second sample signal and a characteristic of the collected acoustic signal. The acoustic filter section has an additional filter that can filter the performance signal in accordance with the additional correction characteristic so as to create the artificial sound as if heard at the particular location. Further expediently, the determining section determines a plurality of additional correction characteristics in correspondence to a plurality of particular locations which are differently situated in a sound field of the natural sound. The inventive apparatus further comprises a selecting section that selects one of the plurality of the additional correction characteristics for enabling the additional filter to create the acoustic signal representative of the artificial sound as if heard at the particular location corresponding to the selected additional correction characteristic. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing configuration of an acoustic reproduction apparatus according to an embodiment of the present invention. FIG. 2 schematically shows an arrangement for using the acoustic reproduction apparatus to provide mute performance of a violin. FIG. 3 shows a mute member attached to a bridge of the violin for the mute performance. FIG. 4 is a flowchart showing a procedure to derive a filter characteristic assigned to an FIR filter as a component of the acoustic reproduction apparatus. FIG. 5 illustrates a method of deriving the filter characteristic by depicting amplitude characteristics on a frequency axis of a sample signal used to derive the filter characteristic. FIG. 6 exemplifies an impulse response derived by the filter characteristic derivation method. FIG. 7 is a flowchart showing a procedure to derive an impulse response assigned to a convolution computing unit as a component of the acoustic reproduction apparatus. FIG. 8 shows a configuration of a modification of the acoustic reproduction apparatus. FIG. 9 shows a configuration of another modification of the acoustic reproduction apparatus. FIG. 10 shows a configuration of yet another modification of the acoustic reproduction apparatus. FIG. 11 shows a configuration of still another modification of the acoustic reproduction apparatus. DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in further detail with reference to the accompanying drawings. A. Acoustic Reproduction Apparatus and Violin FIG. 1 shows a configuration of an acoustic reproduction apparatus (acoustic signal output apparatus) according to an embodiment of the present invention and a violin (stringed instrument) that can be connected to the acoustic reproduction apparatus for mute performance. FIG. 2 shows external views of the acoustic reproduction apparatus and the violin. Like an ordinary acoustic violin as shown in FIG. 2 , a violin 200 connecting with an acoustic reproduction apparatus 100 according to the present invention has a belly (sound generation member) 11 as a resonance body and a neck 12 extending from a neck 12 . Tuning pegs 13 on the neck 12 and a tailpiece 14 on the belly 11 support four strings 15 with tension applied. A fingerboard 16 is arranged almost parallel to the strings 15 on the top surface (as shown in the figure) of the belly 11 and neck 12 . A bridge (support member) 18 is sandwiched between the belly 11 and the strings 15 and transmits vibration of the string 15 to the belly 11 . These components have the same functions as those of ordinary acoustic violins. During normal performance without mute performance, the violin 200 generates sound on the same principle as for ordinary acoustic violins, i.e., sounds acoustically. The acoustic reproduction apparatus 100 can be provided with an attachment so that the apparatus can be attached to a performer's waist belt or the like. By doing so, the performer can play the violin in a natural posture without concern for the position of the acoustic reproduction apparatus 100 and the like. It is necessary to transmit vibration of the bridge 18 as little as possible to the belly 11 so that the acoustic violin 200 is capable of mute performance. A mute member is used as a means for suppressing the vibration transmission. FIG. 3 exemplifies a mute member that suppresses vibration of the bridge 18 . As shown in FIG. 3 , the mute member 301 made of an elastic material such as metal or rubber. The mute member 301 is placed on the top of the bridge 18 that touches the strings 15 to suppress vibration of the bridge 18 in accordance with vibration of the rubbed strings 15 during performance and the like. Suppressing the vibration of the bridge 18 during performance can decrease the amount of vibration transmitted to the belly 11 (see FIG. 2 ) and therefore decrease the volume of generated sound. For the purpose of mute performance, the mute member 301 having the above-mentioned configuration is attached to the bridge 18 to control the amount of acoustically generated musical sound. On the other hand, it is necessary to generate a musical sound corresponding to the performance from a headphone 160 . According to the embodiment, the bridge 18 of the violin 200 is provided with a pickup 110 that detects vibration of the bridge 18 , converts the vibration energy into an electric energy, and outputs an electric signal (detected signal). The detected signal from the pickup 110 reflects the performance operation and is output to the acoustic reproduction apparatus 100 via a signal cable 150 , allowing headphone 160 to output a musical sound corresponding to the performance operation. The following describes the acoustic reproduction apparatus 100 that generates a musical sound from the headphone 160 based on a signal supplied via the signal cable 150 from the pickup 110 attached to the bridge 18 of the violin 200 as mentioned above. As shown in FIG. 1 , the acoustic reproduction apparatus 100 comprises an A/D converter 120 , an FIR (Finite Impulse Response) filter 130 , a convolution computing unit (second acoustic correction filter) 140 , an amplifier 143 , and a D/A converter 144 . When the pickup 110 is attached to the bridge 18 (see FIG. 2 ) of the violin 200 , the A/D converter 120 converts an electric signal supplied from the pickup 110 via the signal cable 150 into a digital signal and outputs this signal to the FIR filter 130 . The FIR filter 130 is assigned a filter coefficient corresponding to filter characteristics derived by a filter characteristic derivation method (to be described) and provides a signal process in accordance with the filter coefficient specified for the electric signal supplied from the A/D converter 120 . The FIR filter 130 is provided with the filter characteristic derived by the filter characteristic derivation method and processes signals as follows. When the mute member 301 (see FIG. 3 ) suppresses vibration of the bridge 18 , the FIR filter 130 is supplied with the characteristic of a signal detected by the pickup 110 . The FIR filter 130 adjusts this characteristic to almost the same characteristic of a signal detected with the mute member 301 not attached, i.e., in a natural manner of generating musical sounds. With the mute member 301 attached, the detected electric signal passes through the FIR filter 130 and is output after converted into a signal having almost the same characteristic as that of the electric signal that is detected with the mute member 301 not attached. When the FIR filter 130 supplies the electric signal with the corrected frequency characteristic, the convolution computing unit 140 convolutes this signal with an impulse response (coefficient sequence) that is derived by an impulse response derivation method to be described. In this manner, the convolution computing unit 140 reflects a specified sound field characteristic on the signal and outputs it as an acoustic signal to the amplifier 143 . The amplifier 143 amplifies the acoustic signal supplied from the convolution computing unit 140 in accordance with a volume specified by an operation device (not shown). The D/A converter 144 converts the acoustic signal supplied from the amplifier 143 into an analog signal and outputs it to the headphone 160 via the signal cable. In this manner, the headphone 160 generates a musical sound corresponding to the performer's operation (rubbing strings). B. Method of Deriving Filter Characteristic and Impulse Response There has been described the configuration of the acoustic reproduction apparatus 100 according to the embodiment and the violin 200 connected to the acoustic reproduction apparatus 100 . When the pickup 110 detects a signal with the mute member 301 attached to the bridge 18 , the acoustic reproduction apparatus 100 according to the embodiment uses this detected signal as the basis of a musical sound to be generated from the headphone 160 . In addition, the acoustic reproduction apparatus 100 makes it possible to prevent the sound quality from degrading and reproduce the sound field more faithfully. The embodiment is characterized by methods of deriving (designing) characteristics of the FIR filter 130 for implementing these features and deriving an impulse response defined for the convolution computing unit 140 . That is to say, the embodiment is characterized by methods of deriving characteristics of acoustic correction filters such as the FIR filter 130 and the convolution computing unit 140 . These derivation methods will be described in detail below. B-1. Method of Deriving FIR Filter Characteristics When the pickup 110 detects a signal caused by vibration of the bridge 18 whose vibration is decreased by the mute member 301 , the detected signal needs to be corrected to a signal detected with the mute member 301 not attached, i.e., to a signal with no degradation of the sound quality due to attachment of the mute member 301 . For this purpose, a filter characteristic needs to be defined for the FIR filter 130 . The method of deriving the filter characteristic will be described with reference to FIG. 4 . As shown in FIG. 4 , the derivation method obtains an electric signal detected by the pickup 110 (step SA 1 ) when a performer plays the violin 200 with the mute member 301 attached to the bridge 18 (hereafter referred to as the mute performance). Concurrently, the derivation method obtains an electric signal detected by the pickup 110 (step SA 2 ) when the mute member 301 is not attached to the same violin, i.e., when the performer plays the violin as a natural musical instrument (hereafter referred to as the normal performance). Here, both performances have the same contents to obtain electric signals. The embodiment enables the sweep performance that smoothly changes pitches, providing waveforms almost free of peaks and dips at all frequencies. The method applies the fast Fourier transform to the electric signals sampled by the respective test performances within a given time period and derives an amplitude characteristic on a frequency axis of each signal (steps SA 3 and SA 4 ). The method then averages the derived amplitude characteristics on the frequency axis according to the arithmetic mean and the running mean (steps SA 5 and SA 6 ). After obtaining the amplitude characteristics for the mute performance and the normal performance, the method extracts a difference between these amplitude characteristics (step SA 7 ) to derive a correction characteristic. As shown in the upper part of FIG. 5 , for example, the mute performance yields an amplitude characteristic Vm. The normal performance yields an amplitude characteristic Vn. In this case, the method finds a correction characteristic Vh for amplitudes on the frequency axis as shown in the lower part of FIG. 5 based on the difference between these amplitude characteristics Vm and Vn, i.e., a ratio thereof. That is to say, the method finds the correction characteristic Vh that is added to the amplitude characteristic Vm for the mute performance to produce the amplitude characteristic Vn for the normal performance. After the correction characteristic Vh is found as mentioned above, the method finds an impulse response as shown in FIG. 6 (step SA 8 ) by providing the correction characteristic Vh with a phase characteristic that satisfies the minimum phase condition. After the impulse response is obtained by providing the correction characteristic Vh with phase characteristic satisfying the minimum phase condition, the method determines that the impulse response to be a filter characteristic for the FIR filter 130 . More specifically, the method determines a level value at each position on the time axis of the impulse response to be a filter coefficient assigned to the FIR filter 130 . As mentioned above, the filter design includes the process of deriving the filter characteristic for the FIR filter according to the difference in amplitude characteristics of the signals detected by the pickup 110 during the mute performance and the normal performance. The filter is created according to this filter design and is mounted on the acoustic reproduction apparatus 100 . By using the FIR filter 130 designed in this manner, it is possible to correct an initial signal with degraded sound quality due to attachment of the mute member 301 to the bridge 18 into an artificial signal having almost the same characteristic of a natural signal that is obtained with the mute member 301 not attached. When the pickup 110 supplies an electric signal to the acoustic reproduction apparatus 100 during the mute performance, the FIR filter 130 outputs a signal having almost the same characteristic of a signal that is detected with the mute member 301 not attached. The headphone 160 generates a musical sound in accordance with the signal output via the convolution computing unit 140 . The audience can listen to the musical sound very similar to that produced in a natural condition. As mentioned above, the FIR filter 130 has the filter characteristic determined by the filter characteristic derivation method. The FIR filter 130 references an amplitude difference in the sample signals detected by the pickup 110 during the mute performance and the normal performance and corrects the amplitude for the corresponding difference. The FIR filter 130 corrects a signal detected by the pickup 110 during the mute performance as if the pickup 110 detects the signal during the normal performance. This is based on the following reason. We directed our attention to the fact that the harmonics distribution hardly changes in a signal whether it is detected by the pickup 110 during the mute performance or the normal performance. We confirmed that it is possible to obtain a signal having almost the same characteristic as that for a signal detected by the pickup 110 during the normal performance by correcting a signal detected by the pickup 110 during the mute performance in accordance with the amplitude difference for each frequency. It has been proved that a good result is obtained by correcting amplitudes correspondingly to amplitude differences on the basis of each frequency of signals detected by the pickup 110 during the mute performance and the normal performance. Based on the proved contents, we adopted the FIR filter 130 having the above-mentioned filter characteristic. B-2. Method of Deriving an Impulse Response (Filter Coefficient) Assigned to the Convolution Computing Unit We assumed that sufficient linearity is maintained between a first transmission process of converting the bridge vibration into a sound by vibrating the musical instrument's body and a second transmission process of delivering the sound generated from the musical instrument to an ear (tympanic membrane) via the space. We also assumed that the above-mentioned two transmission processes are fully simulated by adding the linear conversion of convoluting an impulse response in the signal detected by the pickup 110 and thus the headphone generates a sound faithful to the normal performance. The acoustic reproduction apparatus 100 according to the embodiment adopts the FIR filter 130 having the filter characteristic determined by the above-mentioned method and corrects a signal degraded by attachment of the mute member 301 . In addition, the acoustic reproduction apparatus 100 uses the convolution computing unit 140 to convolute the corrected signal with an impulse response and reproduces the sound field as if the headphone 160 delivers a musical sound generated near the belly 11 of the violin 200 . While the embodiment uses one convolution computing unit 140 to simulate the first and second transmission processes, it may be preferable to find impulse responses individually and provide convolution computing units for simulating the first and second transmission processes, respectively. Referring now to FIG. 7 , the following describes the method of deriving an impulse response (filter coefficient sequence) assigned to the convolution computing unit 140 in order to reproduce the sound field including these two transmission processes. As shown in FIG. 7 , the derivation method uses a performance with the mute member 301 not attached to the violin 200 , i.e., in the same state as for the natural musical instrument (normal performance) and obtains an electric signal detected by the pickup 110 at this time (step SB 2 ). During the normal performance, the method obtains not only the electric signal detected by the pickup 110 as mentioned above, but also an acoustic signal (sound generated by the performance of the violin 200 ) picked up by microphones positioned at both ears of a performer of the violin 200 during the normal performance (step SB 3 ). In order to obtain electric signals, the method uses the sweep performance that smoothly changes pitches to provide waveforms almost free of peaks and dips at all frequencies. The test performance for obtaining sample signals may be held in any place such as an anechoic room, a concert hall, and the like. An impulse response generated on the basis of the obtained signal will have a characteristic that reproduces the conversion from the bridge vibration into sounding of the musical instrument itself and the sound field (reverberant sound and the like in the room space) used for the performance. The performance can be conducted to obtain sample signals in an environment appropriate for the sound field to be reproduced. After obtaining the electric signal detected by the pickup and the acoustic signal at the ears during the normal performance as mentioned above, the method inversely converts the electric signal s(t) detected by the pickup (step SB 4 ) to obtain a signal s −1 (t) that should satisfy an equation s(t)×s −1 (t)=1. The method then convolutes the inversely converted signal s −1 (t) with the acoustic signal p(t) picked up by the microphone (step SB 5 ) and synchronously adds or sums a convolution result hi(t) (step SB 6 ) to derive an impulse response h(t)=Σhi(t) (step SB 7 ). After finding the impulse response h(t), the method specifies it as a filter characteristic for the convolution computing unit 140 . More specifically, a level value at each position on the time axis of the impulse response is specified as a coefficient to be assigned to each multiplier constituting the convolution computing unit 140 . The above-mentioned technique derives the impulse response using the electric signal detected by the pickup 110 during the normal performance and the acoustic signal picked up by the performer's ears during the normal performance. When a signal is supplied from the pickup and passes the FIR filter 130 , the convolution computing unit 140 convolutes this signal with the derived impulse response. Accordingly, the acoustic reproduction apparatus 100 can reproduce the sound field as if the musical sound from the headphone 160 were generated from the vicinity of the belly 11 of the violin 200 . When the normal performance is held to obtain sample signals in a concert hall and the like, the reproduced signals are also provided with reverberant sound characteristics and the like in the concert hall. A person listening to the sound from the headphone 160 can feel the sound field similar to the concert hall. Also during the performance using the mute member 301 attached to the bridge 18 , the acoustic reproduction apparatus 100 according to the embodiment allows the FIR filter 130 having the derived filter characteristic to correct the detected signal generated by vibration of the bridge 18 attached with the mute member 301 . This suppresses degradation of signals due to attachment of the mute member 301 . Moreover, the convolution computing unit 140 convolutes the corrected signal with the derived impulse response. The performer can obtain an impression as if the musical sound from the headphone 160 were generated from the vicinity of the belly 11 . Therefore, attaching the mute member 301 can decrease the volume of actually generated musical sound and ease noise problems for the people outside. On the other hand, the performer can play the violin by listening to musical sound from the headphone 160 almost in the same atmosphere as he or she plays the violin 200 acoustically. Furthermore, the performer uses the ordinary acoustic violin 200 though attached with the mute member 301 . Of course, performance feelings and the like are almost the same as those on the acoustic violin. C. Modifications The present invention is not limited to the above-mentioned embodiments and may be embodied in various modifications as follows. (Modification 1) The acoustic reproduction apparatus 100 according to the embodiment comprises the FIR filter 130 assigned with one derived filter characteristic and the convolution computing unit 140 to convolute with the one derived filter characteristic. It may be preferable to appropriately change either or both of the filter characteristic of the FIR filter 130 and the impulse response convoluted by the convolution computing unit 140 . As shown in FIG. 8 , for example, it may be preferable to implement the same mute performance as the above-mentioned embodiment by using an acoustic reproduction apparatus 100 ′ that further comprises a characteristic setup section (characteristic selection means or selection means 80 , a filter characteristic storage section 81 , and an impulse response storage section 82 in addition to the configuration of the acoustic reproduction apparatus 100 . The characteristic setup section 80 in FIG. 8 follows an instruction of a user (performer and the like) entered from a group of switches (not shown), reads a filter characteristic and an impulse response from the filter characteristic storage section 81 and the impulse response storage section 82 , and assigns the read filter characteristic (filter coefficient) and the impulse response (filter coefficient) to the FIR filter 130 and the convolution computing unit 140 , respectively. The filter characteristic storage section 81 stores the type (product type) of the mute member attached to the bridge 18 of the violin 200 and the filter characteristic (filter coefficient) correspondingly to each other. Each filter characteristic stored in the filter characteristic storage section 81 is found as follows. A filter characteristic A corresponds to a mute member type “member A”. During the performance using the mute member A attached to the bridge 18 , the filter characteristic A is used for the correction corresponding to an amount equivalent to a difference between a signal detected by the pickup 110 and a signal detected by the pickup 110 during the normal performance. The same technique (see FIG. 4 ) as the above-mentioned embodiment is used to find the filter characteristic A. On the other hand, a filter characteristic B corresponds to a mute member type “member B”. During the performance using the mute member B attached to the bridge 18 , the filter characteristic B is used for the correction corresponding to an amount equivalent to a difference between a signal detected by the pickup 110 and a signal detected by the pickup 110 during the normal performance. The same technique (see FIG. 4 ) as the above-mentioned embodiment is used to find the filter characteristic B. The filter characteristic storage section 81 stores filter characteristics that are found in accordance with the same technique as the above-mentioned embodiment through the use of signals detected by the pickup 110 under the condition of attaching the mute member indicated by the mute member type. The characteristic setup section 80 receives from the user a characteristic setup instruction including the type of the mute member to be attached. The characteristic setup section 80 then reads a filter characteristic associated with the mute member type included in the instruction from the filter characteristic storage section 81 that stores a plurality of predetermined filter characteristics. The characteristic setup section 80 sets the read filter characteristic to the FIR filter 130 . The impulse response storage section 82 stores a musical instrument and sound field type and an impulse response (filter coefficient) correspondingly to each other. The musical instrument and sound field type provides information about a sound field where, which musical instrument generated a musical sound at which position in which space. In other words, this information is an impulse response for simulating the first transmission process of converting the bridge vibration into a sound by vibrating the musical instrument's body and the second transmission process of delivering the sound generated from the musical instrument to the ear (tympanic membrane) via the space. The impulse response storage section 82 stores impulse responses each of which has the following characteristic. Impulse response A is associated with musical instrument and sound field type “instrument A, sound field A” and is convoluted for a signal detected by the pickup 110 during the normal performance. Impulse response A is given such a characteristic as to produce an effect as if a musical sound output from the headphone 10 were generated by playing a violin with type A in sound field A. Impulse response B is associated with musical instrument and sound field type “instrument B, sound field B” and is convoluted for a signal detected by the pickup 110 during the normal performance. Impulse response B is given such a characteristic as to produce an effect as if a musical sound output from the headphone 10 were generated by playing a violin with type B in sound field B. Under the condition of “instrument A, sound field A”, for example, a performer plays the violin 200 (with type A) on the stage in a concert hall. The sound source is positioned to the belly 11 of the violin 200 . It is intended to reproduce a sound field where a listener listens to a musical sound generated from this virtual sound source at a specific position of the auditorium in the concert hall. In this case, impulse response A is found as follows. The performer plays the violin 200 on the stage of the concert hall. During this performance, the pickup 110 is attached to the bridge 18 of the violin 200 and detects a signal. During the same performance, a microphone is installed at the specified position of the auditorium and picks up an acoustic signal. The same technique (see FIG. 7 ) as the above-mentioned uses these signals to find the impulse response. The impulse response storage section 82 stores the determined impulse response as impulse response A corresponding to “instrument A, sound field A”. The characteristic setup section 80 receives from the user a characteristic setup instruction including the musical instrument and sound field type to be reproduced. The characteristic setup section 80 then reads an impulse response corresponding to the musical instrument and sound field type included in the instruction from the impulse response storage section 82 that stores a plurality of predetermined impulse responses. The characteristic setup section 80 assigns the read impulse response (filter coefficient) to the convolution computing unit 140 . The FIR filter 130 is thus assigned with the filter characteristic according to the user's instruction. A signal process according to the setup contents is performed for the signal supplied to the acoustic reproduction apparatus 100 ′ from the pickup 110 . When the user supplies a setup instruction including the type of the mute member attached to the bridge 18 of the violin 200 during the performance, the FIR filter 130 is assigned with the filter characteristic corresponding to the specified type of the mute member. With this filter characteristic specified, the acoustic reproduction apparatus 100 ′ may be supplied with the signal detected by the pickup 110 from the bridge attached with the mute member. The FIR filter 130 converts the supplied signal into a signal having almost the same characteristic of the signal detected by the pickup 110 with the mute member not attached. While various mute members can be attached to the violin 200 , the acoustic reproduction apparatus 100 ′ can provide a correction process appropriate the attached mute member when the user supplies a setup instruction including the type of the attached mute member. The convolution computing unit 140 is assigned with an impulse response corresponding to the user-specified musical instrument and sound field type. A signal process according to the setup contents is performed for the electric signal supplied to the acoustic reproduction apparatus 100 ′ from the pickup 110 , reproducing the user-specified sound field. (Modification 2) The above-mentioned embodiment determines the filter characteristic of the FIR filter 130 in accordance with a difference between the signal detected by the pickup 110 with the mute member 301 attached to the violin 200 and the signal detected by the pickup 110 with the mute member 301 not attached to the violin 200 . In this manner, it may be preferable to determine the filter characteristic in accordance with a difference between signals that are detected with the mute member 301 attached or not attached to the same violin 200 . It may be also preferable to use another violin, e.g., with a higher grade than that of the violin 200 in order to obtain signals during the normal performance. Like the above-mentioned embodiment, the FIR filter 130 is assigned with the filter characteristic corresponding to a difference between the signal detected by the pickup attached to the bridge of the high grade violin and the signal detected by the pickup 110 of the violin 200 attached with the mute member 301 . When the FIR filter 130 is assigned with the derived filter characteristic, the performer can listen to a simulated sound of the high grade violin from the headphone 160 while playing the violin 200 attached with the mute member 301 . (Modification 3) FIG. 9 shows a configuration of an acoustic reproduction apparatus 100 ″ provided with a reproduction correction filter 90 after the convolution computing unit 140 in the acoustic reproduction apparatus 100 . It may be preferable to reproduce a sound field that makes the performer to feel as if he or she listened to a musical sound without using the headphone while actually listening to the sound from the headphone 160 . More specifically, the headphone 160 is mounted on a dummy head and generates an impulse sound. A microphone picks up the impulse sound generated from the headphone 160 . A signal of the received impulse sound is inversely transformed to yield a characteristic that is assigned as the filter characteristic of the reproduction correction filter 90 . Since such filter characteristic is assigned to the reproduction correction filter 90 , it is possible to reproduce a sound field that makes the performer to feel as if he or she listened to a musical sound without using the headphone as mentioned above. (Modification 4) FIG. 10 shows a configuration of an acoustic reproduction apparatus 500 provided with a plurality of convolution computing units 140 a and 140 b (two units in this example) assigned with impulse responses for reproducing different sound fields. The convolution computing unit 140 a and 140 b may output acoustic signals assigned with different sound field characteristics to headphones 160 a and 160 b via amplifiers 143 a and 143 b and D/A converters 144 a and 144 b , respectively. For example, the convolution computing unit 140 a may be configured to convolute an input signal with the impulse response found by the same technique as the above-mentioned embodiment. The convolution computing unit 140 b may be configured to convolute an input signal with the impulse response for reproducing a sound field different from that of the impulse response for the convolution computing unit 140 a . For example, the sound field for the convolution computing unit 140 b may allow a listener to feel as if he or she listened to music played by a performer at the auditorium in a concert hall. The performer listens to the musical sound from the headphone 160 a . Another person listens to the musical sound from the headphone 160 b . The performer can experience the sound field as if he or she played music on the stage. The other person can experience the sound field as if he or she listened the music at the auditorium. (Modification 5) According to the above-mentioned embodiment, manufacturers and the like define the filter characteristic assigned to the FIR filter 130 and the impulse responses assigned to the convolution computing unit 140 . The acoustic reproduction apparatus 100 may be configured to derive the filter characteristic assigned to the FIR filter 130 (configuration for implementing the process in FIG. 4 ) and/or derive the impulse response assigned to the convolution computing unit 140 (configuration for implementing the process in FIG. 7 ). It may be preferable to allow the user to determine these characteristics. FIG. 11 shows a configuration of an acoustic reproduction apparatus provided with the above-mentioned characteristic derivation function. As shown in FIG. 11 , an acoustic reproduction apparatus (filter characteristics determination apparatus and acoustic signal output apparatus) 600 comprises a communication interface 601 , a signal input terminal 602 , a filter characteristic derivation section 603 , and memory 604 in addition to the above-mentioned A/D converter 120 , the FIR filter 130 , the convolution computing unit 140 , the amplifier 143 , the D/A converter 144 , the characteristic setup section 80 , the filter characteristic storage section 81 , and the impulse response storage section 82 . The communication interface 601 functions between the apparatus and a server (not shown) connected to a network (not shown) such as the Internet and the like and interchanges data via the network. The communication interface 601 incorporates data supplied from the server and the like into the acoustic reproduction apparatus 600 . The signal input terminal 602 inputs a signal for deriving the filter characteristic assigned to the FIR filter 130 in the acoustic reproduction apparatus 600 . For example, the signal input terminal 602 inputs a signal detected by the pickup 110 of the violin 200 . The memory 604 stores signals supplied from the signal input terminal 602 , data incorporated by the communication interface 601 , and the like. The filter characteristic derivation section 603 derives the filter characteristic according to the same technique as the above-mentioned embodiment (see FIG. 4 ) based on signals and data stored in the memory. The filter characteristic derivation section 603 newly writes the derived filter characteristic (filter coefficient) to the filter characteristic storage section 81 . According to the above-mentioned configuration, the acoustic reproduction apparatus 600 derives a new filter characteristic as follows. A new filter characteristic may need to be derived, e.g., when the performer purchases a new type of mute member. The following describes how to derive the filter characteristic when a new mute member is purchased. The pickup 110 of the violin 200 is connected to the signal input terminal 602 . When the violin 200 is played, the pickup 110 detects a signal. This signal is incorporated into the acoustic reproduction apparatus 600 and is stored in the memory 604 . Here, the apparatus inputs a signal detected by the pickup 110 with the newly purchased mute member attached and a signal detected by the pickup 110 with the mute member not attached and stores these signals in the memory 604 . The filter characteristic derivation section 603 derives a filter characteristic according to the same technique as the above-mentioned embodiment (see FIG. 4 ) based on the two signals stored in the memory 604 . That is to say, the filter characteristic derivation section 603 derives a filter characteristic corresponding to a difference between amplitudes on the frequency axis and stores the derived filter characteristic in the filter characteristic storage section 81 in correspondence with information indicating the type of the newly purchased mute member. In this manner, the filter characteristic storage section 81 stores a new filter characteristic and assigns the stored filter characteristic to the FIR filter 130 . Even when attaching the newly purchased mute member to the violin 200 , the performer can prevent the quality of a musical sound output from the headphone 160 from degrading due to attachment of the mute member. It may be preferable to newly derive the filter characteristic as follows. The performer plays the violin with the mute member not attached. A signal detected by the pickup 110 is stored in the memory 604 instead of being incorporated from the signal input terminal 602 . The stored signal is used to derive the filter characteristic. A user of the acoustic reproduction apparatus 600 may otherwise need to newly derive the filter characteristic in addition to the above-mentioned case of purchasing a new mute member. The user may need to derive a filter characteristic for correcting a signal detected by the pickup 110 with the mute member attached into a signal having almost the same characteristic of a signal detected with no mute member attached to a violin other than the user's violin 200 . More specifically, the user may want to enjoy timbres and the like of a violin other than his or her own violin 200 by means of musical sounds output from the headphone 160 . For this purpose, it is necessary to derive the filter characteristic as mentioned above and assign it to the computing unit 140 . If the user purchases another violin in this case, for example, it is possible to derive a new filter characteristic by supplying the acoustic reproduction apparatus 600 with a signal detected by a pickup for the purchased violin. However, purchasing another violin is uneconomical for the user. According to the following method, the user's acoustic reproduction apparatus 600 can derive a new filter characteristic for providing timbre and the like of a different violin. First of all, manufacturers and the like of the violin or the acoustic reproduction apparatus 600 store signal waveform data in a server connected to the Internet and the like. The signal waveform data is detected by a pickup attached to the bridge of the violin when a plurality of specified types of violins is played in a specified manner. The user accesses the server via the Internet and the like, retrieves signal waveform data detected by the pickup of an intended violin, and downloads that data into the acoustic reproduction apparatus 600 via the communication interface 601 . The signal waveform data downloaded via the Internet indicates the signal detected by the pickup of the different violin. Using this signal, the user can allow the acoustic reproduction apparatus 600 to derive a filter characteristic for simulating timbre of the different violin without purchasing a new violin. The server may store not only signal waveforms, but also impulse response data. Directly using this data as a filter coefficient can provide the same effects as those mentioned above. (Modification 6) According to the above-mentioned embodiment, the acoustic reproduction apparatus 100 corrects a signal detected by the pickup 110 attached to the bridge 18 of the violin 200 . The headphone 160 outputs musical sound of the violin 200 attached with the mute member to implement the mute performance. The present invention can be applied to musical instruments such as a cello, a contrabass, and the like that generate musical sound by transmitting string vibration to a resonance member and the like. As mentioned above, the present invention can output a signal capable of generating a musical sound of good quality based on a signal obtained in accordance with string vibration even when the vibration suppression means such as a mute member is attached.

A method is provided for designing an acoustic correction filter applicable to a stringed instrument, which is composed of a string member operable to undergo a vibration, a support member for supporting the string member, a body member responsive to the vibration transmitted through the support member for generating a natural sound and a mute attachment for muting the natural sound. The acoustic correction filter is operable when the natural sound is muted by the mute attachment for filtering a signal derived from the vibration so as to create an artificial sound instead of the muted natural sound. The method is carried out by the steps of acquiring a first sample signal from the vibration under a mute state, acquiring a second sample signal from the vibration under a free state, extracting a difference between the acquired first sample signal and the acquired second sample signal, and determining a correction characteristic of the acoustic correction filter based on the extracted difference such that the acoustic correction filter can filter the signal in accordance with the determined correction characteristic so as to create the artificial sound comparable to the natural sound.

CROSS-REFERENCE TO RELATED APPLICATION This application is being filed simultaneously with an application containing some common subject matter, and which is entitled "PACKER COOLING SYSTEM FOR A DOWNHOLE STEAM GENERATOR ASSEMBLY", Ser. No. 121,485 filed Nov. 17, 1987, by inventors John Lindley Baugh, et al. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to a system for generating steam downhole in oil wells, and in particular to a packer and electrical connector apparatus used with a steam generator. 2. Description of the Prior Art Steam is used in some cases to facilitate the production of oil from reservoirs having very viscous crude. In the prior art, steam is generated at the surface and pumped down tubing in injection wells. The steam will flow through perforations in the casing of the injection well to heat the crude and force it to flow to producing wells. One disadvantage of steam injection systems is the energy loss which occurs as the steam cools while being pumped from the surface down to the perforations. This is particularly a problem in deeper wells. Proposals have been made to pump water down the well and generate the steam downhole. This would avoid the heat loss that occurs while the steam is being pumped down the well in conventional systems. The downhole steam generator would generate the steam using high voltage electrical power supplied through electrical cable extending down into the well. A packer above the steam generator would prevent the steam from flowing back up the annulus of the well. One problem presented by a downhole steam generator is providing the electrical connections. Conventional downhole electrical connections are unable to withstand the high temperatures at the voltage and power levels required. The power requirements for a downhole steam generator are high, up to 7200 volts and 240 amps. The temperatures are high, possibly exceeding 600 degrees F. Packers are available that have feed through mandrels for electrical wires to be connected for purposes other than downhole steam generators. The feed through mandrel is located to one side of the main conduit in the packer for the tubing. The feed through mandrel has insulated conductor rods extending through the packer. The lower end of the upper section of the cable is connected to the upper end of the connector rod. The upper end of the lower section of cable below the packer is connected to the lower end of the conductor rod. The conventional feed through mandrel would not be acceptable for use in a downhole steam generator system. The high temperatures would cause deterioration of the elastomeric insulators in the feed through mandrel. Also, the feed through mandrel has a rather small diameter, necessitating that the three conductors from the power cable be spaced quite close to each other. This results in the possibility of insulation failure between the conductors because of the high voltage. SUMMARY OF THE INVENTION In this invention, a connector box is located between the downhole steam generator and the packer. The connector box is an insulated sealed housing that extends downward from the packer. The connector box communicates with the interior of the packer and with the suspension tubing that extends upward from the packer. The power cable extends down from the surface alongside the suspension tubing until a point a short distance above the packer. At that point, the power cable extends through a window provided in the suspension tubing. The power cable extends through the interior of the packer and into the connection box. In the connection box, the feed through connections are made. Also, heat pipes extend through the packer from the connector box to a point above the packer. These heat pipes are sealed elements containing a gas such as ammonia which circulates due to convection. The circulation aids in the dissipation of heat from the interior of the connector box. BRIEF DESCRIPTION OF THE DRAWING FIGS. 1A, 1B and 1C are a side view, partially in section, of a completion system for a downhole steam generator constructed in accordance with this invention. FIG. 2 is an enlarged vertical sectional view of one of the feed through connectors used with the completion system of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1A, the well contains casing 11. A water supply tube or line 13 will extend from the surface down through the casing 11 to a steam generator 15, shown in FIG. 1C. The water supply line 13 is offset from the axis of the casing 11. The steam generator 15 is not shown in detail. It will have electrodes for heating the water supplied through the water supply line 13 sufficiently to cause steam to flow into the earth formation. As shown in FIG. 1B, a packer 17 is located above the steam generator 15. The packer 17 will be a conventional high temperature packer having an elastomeric sealing element 18 which is expanded into sealing engagement with the casing 11. Packer 17 is preferably of a type that is set by hydraulic pressure, and once set, the sealing element 18 will remain in place even though the hydraulic pressure is relieved. The packer 17 is lowered into place on a string of suspension tubing 19, shown also in FIG. 1A. Tubing 19 is usually at least twice the diameter of the water supply line 13. The tubing 19 extends to the surface and is made up of sections approximately 30 feet in length screwed together. As shown in FIG. 1A, a coupling 21 connects the tubing 19 to a tubing joint 23, which is also part of the string of tubing 19. Joint 23 is secured to the top of the packer 17 (FIG. 1B) in axial alignment with a passage 24 extending through the packer 17. A setting tube 25 extends from the coupling 21 to the packer 17 (FIG. 1B). A plate (not shown) in the coupling 21 directs water pumped down the tubing 19 into the setting tube 25. The water enters the packer 17 and acts against a conventional setting mechanism (not shown) in the packer 17 to expand the sealing element 18. As shown in FIG. 1A, a window 27 is formed in the joint 23 directly above the packer 17. A power cable 29 extends from the surface alongside the tubing 19. Power cable 29 enters window 27 and passes straight through the passage 24 in the packer 17, through a conduit 33, and into a connection box 35, shown in FIG. 1B. Power cable 29 has three insulated electrical wires 31 (FIG. 1B). Power cable 29 is wrapped in a metallic outer armor 32. The armor 32 terminates below the passage 24, and the lower ends of the wires 31 protrude a short distance below the armor 32. Referring to FIG. 1B, conduit 33 is insulated and coaxial with the passage 24. The connector box 35 is mounted to the lower end of the conduit 33. Connector box 35 is a sealed insulated housing in communication with the interior of the conduit 33, the passage 24 and the tubing joint 23. Connector box 35 is cylindrical and has a diameter that is as large as possible, preferably at least three-fourths the inner diameter of the casing 11. The axis of the connector box 35 is offset from the axis of casing 11. The water supply line 13 extends alongside the connector box 35. A plurality of heat pipes 36 extend from the connector box 35 upward through the conduit 33, packer passage 24 and into the tubing joint 23, as shown in FIG. 1A. The top of each heat pipe 36 is adjacent the window 27. Each heat pipe 36 is sealed and contains a gas such as ammonia. The greater heat in the connector box 35 than above packer 17 will cause the gas in the heat pipes 36 to rise. The temperature at the top of each heat pipe 36 adjacent the window 27 (FIG. 1A) is cooler than in the connector box 35. This causes the gas to cool at the top and circulate back due to convection. The circulation within each heat pipe 36 assists in removing heat from the connector box 35 and dissipating the heat to a point above the packer 17. Referring to FIG. 1C, the connector box 35 has a cylindrical sidewall 37 and a bottom connector plate 39. The plate 39 has a neck 41 that is closely received in the sidewall 37. Seals 43 seal the interior of the connector box 35 from the exterior. The connector box 35 is preferably filled with a dielectric electrical insulating fluid. Three passages 45 extend through the plate 39. A feed through connector 47 is located in each passage 45. The power cable wires 31 are connected to the feed through connectors 47. Also, wires 49 leading upward from the steam generator 15 are connected to the lower ends of the feed through connectors 47. An adapter plate 51 is located between the connector box 35 and the steam generator 15. The adapter plate 51 is connected to the connector box 35 by a plurality of rods 53 (only one shown). A support tube 55 extends between the adapter plate 51 and the steam generator 15. Referring to FIG. 2, each insulated wire 31 from the power cable 29 (FIG. 1A) has an electrical conductor 57 located within an insulating jacket 59. A connector 61 having a male threaded end is joined to the lower end of the conductor 57. A female connector 63 has a threaded upper end that screws onto the male end of the connector 61. The lower end of female connector 63 is tubular. The connectors 61, 63 provide an electrical terminal for each wire 31. An elastomeric boot 65 surrounds the connectors 61, 63. A feed through rod 67 is located in the plate passage 45. The feed through rod 67 has male ends 67a and 67b on each end. The feed through rod 67 is molded in an insulator 69 that is located within the passage 45. A nut 71 secures the insulator 69 in the passage on the upper end. A fitting 73 is welded to the lower side of plate 39 concentric with each passage 45. Fitting 73 supports the lower end of the insulator 69. The wires 49 each include an electrical conductor 75 located within an insulating jacket 77 that is made up of mineral insulation. A steel sheath 79 surrounds the insulating jacket 77. A female terminal or connector 81 is located on the upper end of the steam generator wire 49. A nut 83 engages threads on the fitting 73 to secure the steam generator wire 49 in place on the lower end 67b of each feed through rod 67. In operation, the steam generator 15 is assembled with the connector box 35 and packer 17 at the surface. This assembly is lowered on the tubing 19 to the desired level. The power cable 29 and the water supply line 13 are lowered at the same time. Then, water is pumped down the tubing 19 and into the setting tube 25. The water flows into the setting mechanism (not shown) of the packer 17 (FIG. 1B) and causes the packer 17 to expand its sealing element 18 outward into sealing engagement with the casing 11. Then, electrical power is supplied from the surface to the power cable 29. The three phase power passes through the feed through connectors 47 (FIG. 1C) to the steam generator 15. Water is pumped down the water supply line 13 to the steam generator 15. The steam generator 15 heats the water to cause steam which then flows into the formation. The pressure of the water and the heat from the steam cause the crude in the formation to flow up adjacent production wells. The invention has significant advantages. The connector box provides a greater diameter than conventional feed through mandrels for packers. This allows the feed through connector rods to be spaced farther distances apart, thereby significantly improving the ability to insulate against the high voltage. By passing the power cable completely through the main passage in the packer a separate feed through mandrel in the packer is not required. Positioning a connector box below the packer also allows a conventional packer to be used using lower temperature components than would otherwise be required. The heat pipes aid in dissipating heat from the connector box. While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art, that it is not so limited but is susceptible to various changes without departing from the scope of the invention.

A steam generator is located downhole in a well for generating steam to cause viscous crudes to flow out adjacent walls. A packer is mounted above the steam generator. A connector box is located between the packer and the steam generator. An electrical cable extends alongside tubing into the well and into a window in the tubing located just above the packer. The cable extends through a passage in the packer and into the connector box. Feedthrough connectors in the connector box connect the power cable with lead wires extending upward from the steam generator. Heat pipes extend from the connector box upward through the packer. The heat pipes contain gas which circulates to aid in dissipating heat from the connector box.

[0001] This application claims priority of PCT application PCT/CH2007/000559 having a priority date of Mar. 27, 2007, the disclosure of which is incorporated herein by reference. TECHNICAL FIELD [0002] The invention relates to a device for controlling the transverse movement of the warp threads of a textile weaving machine, in particular of a textile weaving machine having individual heddle movement. BACKGROUND OF THE INVENTION [0003] Devices for controlling the transverse movement of the warp threads of textile weaving machines, in particular of weaving machines having individual heddle movement, are basically known from numerous documents. In many of these publications, attempts are made to put forward suitable proposals so that the problematic weaving harness of a shedding device of a Jacquard machine can be dispensed with. [0004] EP 0 353 005 A1 discloses a drive arrangement for controlling the transverse movement of the warp threads, in which, with a linear motor, a closed drive cord for the heddles which is guided via four rotating rollers is proposed. However, the implementation of the invention disclosed in EP 0 353 005 A1 comes up against difficulties which are based, on the one hand, on the fact that, with a relatively large number of warp threads arranged next to one another, sufficient space could not be made available for a large number of linear motors, but also for the deflecting rollers, and, on the other hand, on the fact that the deflection of the linear motors proposed there was, in a justifiable version, too small for the necessary transverse movements of the warp threads. [0005] It is known from WO-A-98/24955 to tension-mount the driving part of a weaving machine—in this case, a heddle or a heddle shaft—between two spring parts and to provide an electric drive which raises or lowers the driving part, together with the warp threads, for shedding purposes. This invention also discloses the proposal to design the above-described arrangement as a free oscillator such that a large part of the kinetic energy from the elastic spring force is applied, while the electric drive is intended rather as compensation for the energy losses and to activate the corresponding device. However, the version with the two springs in WO-A-98/24955 likewise takes up a relatively large amount of space, as may also be gathered from the drawings there. Furthermore, it seems difficult, in the arrangement proposed in WO-A-98/24955, on the one hand, to keep the build of the electric motor small, but, on the other hand, to design it with such high power and high movement that it fulfills the requirements when a multiplicity of warp threads lying next to one another are to undergo shedding. [0006] Further publications, such as, for example, WO-A-/ 11327 or WO-A-2006/114188, are likewise concerned with a free oscillator arrangement, but without being able to solve the problems mentioned above. [0007] EP 1 063 326 A1 discloses cord drives for the heddles of a textile weaving machine having individual heddle movement, and it is proposed there to wind the cords on one side onto electromotively driven cord rollers and to keep them tensioned on the other side by means of a helical spring fastened to the loom. However, the principles of a free oscillator, which are already known from the document mentioned above, are not implemented by means of the device from EP 1 063 326 A1. [0008] Finally, WO-A-2006/063584 discloses a shedding device with individual thread control, in which, in a basically known way, a lifting spring frame or a fixed spring frame with a retaining element for the individual heddles is proposed. However, this type of shedding has proved to be susceptible to faults, since the retaining elements mentioned are basically temperamental. [0009] EP 0 347 626 A2 and DE 198 49 728 A1 disclose electromotive drives for the shedding of weaving machines, which have a coil and a sheet-like permanent magnet, by means of which a rotational movement is proposed for shedding. In this case, a lever action (step-up) is proposed in EP 0 347 626 A2. SUMMARY OF THE INVENTION [0010] The object of the invention is to improve a device for controlling the transverse movement of the warp threads of a textile weaving machine, in particular of a textile weaving machine having individual heddle movement. [0011] In this case, the measures of the invention result, in the first place, in a very low space requirement, along with a high weaving speed. Due to the register-like fanning out of the heddle drives and to the spring assistance, it is possible to keep the electric drive motors small. Moreover, owing to the lever-like intensification, it becomes possible for the drive travel of these motors to be kept small. [0012] It is advantageous if one at least double step-up is provided, that is to say a movement of the electric motors causes an at least twice as great a movement of the heddles. [0013] A refinement with pull and push rods as force transmission elements for the drive of the driving elements, which may be generally conventional heddles, but, in a special case, also guide eyes, which are attached directly to the pull and push rods, affords, a simple embodiment of the invention. [0014] An advantageous embodiment is proposed with a drive of the heddles by cords as force transmission elements which are connected to the electric motors, the fan-like or register-like arrangement being made possible by means of deflecting rollers or, in a further advantageous refinement, by means of deflecting levers with a stroke step-up. The deflecting rollers or deflecting levers in this case deflect the cords preferably through 60° to 120°, most preferably through 75° to 105°, in order to provide as much space as possible for register-like fanning out. If two springs are used in this case, for example, one of the springs may be arranged on the side of the heddles which lies opposite the deflecting rollers or deflecting levers and be designed as a conventional tension spring. [0015] The kinetic energy of the heddles may be made available predominantly by springs. The springs are in this case set up such that they make available in a first end position and in a second end position in each case high potential energy as force which drives the heddles in the direction of the other end position. In one position, in a solution with a spiral compression spring, the spring force disappears. In a solution with a compression spring and tension spring or a solution with two opposite tension springs, the potential energies of the two springs cancel one another. During movement, therefore, in a position which is advantageously the middle position, the heddles have a maximum speed. The heddles are then moved further on into the other end position in each case, the springs then being capable of absorbing the kinetic energy of the heddles in the form of potential energy. In order to allow controlled movement and selective dwelling in the first or the second end position, for the first end position and for the second end position in each case holding means are provided which stop the movement and hold the respective heddle in the end position assumed. In order to allow controlled movement, then, a selectively switchable electric motor is additionally provided. This, together with the spring force, overcomes the holding force of the holding means and can thus free the heddle from its holding position. Basically, therefore, the motor is intended for releasing the holding means and for initiating the movement action. Furthermore, the motor serves for compensating energy losses and for adapting the device to changing operating conditions. The device is controlled by means of the control of the motor. [0016] It is advantageous if at least 75% of the kinetic energy is extracted from the spring or springs and the electric motor applies at most 25% of the kinetic energy. Furthermore, it is advantageous if the holding means are designed, uncontrolled, as permanent magnets which cooperate with magnetic stays, the ends of the step-up lever serving as magnetic stays. Advantageously, in a third shed position between the upper shed and the lower shed position, no force is exerted on the heddles. In a symmetrical arrangement, this is a middle shed position. [0017] The abovementioned elements to be used according to the invention, and also those claimed and those described in the following exemplary embodiments, are not subject to any special exceptional conditions in terms of their size, shape, use of material and technical design, and therefore the selection criteria known in the respective field of use can be adopted unrestrictively. [0018] In particular, the invention is not restricted to a textile weaving machine having individual heddle movement. On the contrary, the invention may also be used for a weaving machine in which heddles are combined, for example by means of heddle shafts, etc. BRIEF DESCRIPTION OF THE DRAWINGS [0019] Exemplary embodiments of a device for textile machines, in particular a textile weaving machine having individual heddle movement, are described in more detail below with reference to the drawings in which: [0020] FIG. 1 shows a heddle drive according to a first exemplary embodiment of the invention with pull and push rods, accumulator spring and torque motor; [0021] FIG. 2 shows an illustration of the torque motor according to FIG. 1 as a detail; [0022] FIG. 3 shows a force graph for the movement sequences of the warp threads; [0023] FIG. 4 shows a heddle drive according to a second exemplary embodiment of the invention with tension spring, spiral spring, cord elements and torque motor; [0024] FIG. 5 shows an illustration of the torque motor according to FIG. 1 as a detail; [0025] FIG. 6 shows a heddle drive according to a third exemplary embodiment of the invention with tension springs, cord elements and linear motor; and [0026] FIG. 7 shows an illustration of the linear motor of FIG. 6 as a detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0027] A first exemplary embodiment for carrying out the present invention is illustrated in FIGS. 1 and 2 . [0028] FIG. 1 shows a device for driving the heddles 4 , designed as driving parts of the warp threads 2 , of a textile weaving machine having individual heddle movement, in a side view. The warp threads 2 are moved by means of the heddles 4 having thread eyes 3 , such that, as illustrated in the exemplary embodiment, they are located either in an upper shed position or in a lower shed position. The heddles 4 are arranged by means of couplings 36 on push and pull rods 30 which in each case have a length different from that of the adjacent rod. The drive elements for the heddles 4 can thereby be arranged in a staggered or register-like manner. The staggered or register-like arrangement is provided here in duplicate form, in such a way that the left half of the heddles 4 is assigned to a left register of electric motors 32 and the elements assigned to these, while the right half of the heddles 4 is assigned to a right register of electric motors 32 , virtually in a mirror-symmetrical arrangement, and the elements assigned to these. The ends of the push and pull rods 30 are in each case fastened to an operative lever 28 which is operatively connected to an electric motor 32 designed as a pivoting motor. Each electric motor 32 has a coil 6 which is fastened to a coil carrier 20 pivotable about an axis 19 . The coil former, in turn, is arranged between two base plates 18 . Each electric motor 32 has, furthermore, a permanent-magnetic plate 16 . Thus, by means of the polarity of a current flowing through the respective coil, the coils assume one of two end positions which are marked in the drawing. These two positions correspond to the two positions “upper shed” or “lower shed” of the heddles 4 and consequently the shedding of the warp threads 2 . [0029] However, the position of the abovementioned elements is not free, but is prestressed by a spiral tension and compression spring 8 such that, in the two end positions “upper shed” and “lower shed”, a spring force directed away from the stops takes effect, while in a middle position of the coils 6 , no spring force takes effect. Two stop magnets 26 are arranged such that they form holding means for the two end positions “upper shed” and “lower shed”. [0030] The graph 3 shows the force conditions of the elements described above. In this case, the spring force graph 100 shows that the spring force of the spiral tension and compression spring 8 is symmetrical about the middle position, in which it disappears, and is linear. During a raising or lowering movement of the heddles 4 , the largest fraction of energy is applied by the spring drive of the spiral tension and compression spring 8 . However, the movement is initiated by an electric motor 32 . As long as the electric motor 32 is not in operation, the corresponding heddle 4 is retained by the upper or the lower stop magnet 26 in the upper or lower end position, which correspond to the upper shed position or the lower shed position of the warp threads of a shed. This is achieved in that the stop magnets 26 designed as permanent magnets have a higher holding force 102 than the restoring force of the spiral tension and compression spring 8 during deflection in the end positions. It should be pointed out that the holding force of the stop magnets 26 has a short range and is therefore relevant at all only in the vicinity of the levers 28 and therefore only in or in the vicinity of the respective end position. [0031] In order, then, to set the heddles 4 in motion, that is to say to initiate a movement from the upper to the lower end position or from the lower to the upper end position, the corresponding coils 6 are supplied with voltage and the electric motors 32 is thus put into operation. The sum of the active forces 104 of the electric motor and of the spring force 100 of the spiral tension and compression spring 8 in a deflective state, that is to say in one of the end positions, is greater than the holding force 102 of the corresponding stop magnets 26 . [0032] If, then, the holding force of the stop magnets 26 is overcome, the movement of the heddle via the corresponding push and pull rod 30 is brought about predominantly by the spring force of the spiral tension and compression spring 8 , the electric motor 32 cooperating in this movement, without appreciably contributing to it. When the other end position is reached, that is to say, for example, the lever 28 comes into the active range of the lower stop magnet 26 , the new end position is reached and the spiral tension and compression spring 8 remains deflected, since, in this position, the force of the permanent magnet 26 is higher than the restoring force of the spiral tension and compression spring 8 and the electric motor 32 does not assist the latter. [0033] In the exemplary embodiment shown here, the spiral tension and compression spring 8 is operated in the linear range, so that the spring force graph 100 can be represented by a straight line. The spring force is assisted only insignificantly by the warp thread force 106 , and therefore the warp thread force 106 plays no part here. The stop magnet graph 102 clearly shows the short range of the magnetic forces which act only when the levers 28 are in the immediate vicinity of the stop magnets 26 and an end position is assumed. The coil force graph 104 of the electric motor 32 has, in the operating mode described here, a constant force which may point in one direction or the other, depending on polarity. [0034] In the exemplary embodiment described here, the electric motor 32 is designed such that, in addition to the upper position and the lower position, a middle position of the heddle 4 can be assumed and the heddle 4 can be moved out of this middle position into the upper position or into the lower position. The purpose of this operating mode is that a position of rest can be assumed in which the spiral tension and compression spring 8 exerts no force on the push and pull rod 30 and the corresponding heddle 4 . The heddle 4 is controlled solely by means of the electric motor 32 which, for this purpose, is connected to a control unit of a weaving machine in a way not illustrated in any more detail. [0035] FIG. 4 and FIG. 5 illustrate a device for driving the heddles of a textile weaving machine having individual heddle movement, in a side view, according to a second exemplary embodiment. [0036] In this exemplary embodiment, wire cords 24 serve as pull elements. The wire cords 24 are connected to the heddles 4 in a conventional way, for example by means of couplings, and in each case have a length different from that of the adjacent cord. As a result, the drive elements can, in turn, be arranged in a staggered or register-like manner. Here, too, the staggered or register-like arrangement is provided in duplicate form in such a way that the left half of the wires cords 4 is assigned to an upper register of electric motors 32 likewise designed as a pivoting motor and the elements assigned to these, while the right half of the wire cords 24 is assigned to a lower register of electric motors 32 and the elements assigned to these. The ends of the wire cords 24 are in this case likewise fastened to an operative lever 28 which is operatively connected to an electric motor 32 . The electric motor has basically the same set-up as in the first exemplary embodiment. [0037] In this exemplary embodiment, the heddles 4 are prestressed, on the side facing away from the electric motor, in the lower shed position in each case by means of a tension spring 12 . In this exemplary embodiment, the spring force counter to the tension spring 12 is brought about by spiral springs 10 which are arranged on the electric motor 32 . In this case, the forces of the tension spring 12 and of the spiral spring 10 cancel one another in a middle position of the coils 6 . Two stop magnets 26 are arranged, in turn, such that they form holding means for the two end positions “upper shed” and “lower shed”. The conditions are otherwise identical to or correspond to the first exemplary embodiment. [0038] FIG. 6 and FIG. 7 illustrate a device for driving the heddles of a textile weaving machine having individual heddle movement, in a side view, according to a third exemplary embodiment. [0039] In this exemplary embodiment, the wire cords 24 likewise serve as pull elements for the heddles. The wire cords 24 again have in each case a length which is different from that of the adjacent cord. As a result, the drive elements can again be arranged in a staggered or register-like manner. Here, too, however, the staggered or register-like arrangement is provided in a simple way. [0040] The ends of the wire cords 24 are fastened about an axis to a pivotable operative lever 22 which is operatively connected to an electric motor 34 . [0041] The difference from the second exemplary embodiment is here, in particular, that the cord deflection is not formed by deflecting rollers, but by an operative lever 22 which is pivotable about the axis and which is coupled by means of a to the electric motor 34 . The electric motor 34 is designed here as a linear motor. In this exemplary embodiment, the wire cords 24 are prestressed by two tension springs 12 such that in each case the spring force of a tension spring 12 takes effect in the two end positions “upper shed” and “lower shed”. In this case, the forces of the tension springs 12 cancel one another in a middle position of the coils 6 of the electric motor 34 . Two stop magnets 26 are again arranged such that they form holding means for the two end positions “upper shed” and “lower shed”. The conditions are otherwise identical to or correspond to the first exemplary embodiment. [0042] It should be emphasized for clarity that, in the description of the invention and particularly in the description of the preferred exemplary embodiments, a distinction was made between the heddles 4 and the force transmission elements 24 and 30 . However, the push and pressure rods 30 may also be continuous and therefore also form the heddles. Furthermore, the cords 24 may also have eyes for leading through the warp threads and consequently at the same time form the heddles. LIST OF REFERENCE SYMBOLS [0000] 2 Warp threads 3 Thread eye 4 Heddles with thread eye 6 Coil 8 Spiral tension and compression spring 10 Spiral compression spring 12 Tension spring 14 Deflecting roller 16 Permanent-magnetic plate 18 Base plate 19 Axis 20 Coil carrier 22 Cord deflection with reduction to linear drive 24 Wire cord, pull element 26 Stop magnets 28 Lever 30 Push and pull rods 32 Electric motor, torque motor 34 Electric motor, linear motor 36 Coupling 100 Spring force graph 102 Stop magnet graph 104 Coil force graph 106 Warp thread graph

In order to solve the problem of not having enough space available for a large number of components and keeping the deflection of the electric motor small in a device for controlling the transverse movement of the warp threads of a textile weaving machine, particularly a textile weaving machine with single strand movements, the invention proposes to operatively connect the strands via power transmission elements having different lengths in a staggered or register-like way to an electric motor and to provide the electric motors with a ratio in relation to the strands such that the movement of the electric motors brings about a greater movement of the strands.

CROSS-REFERENCE TO RELATED APPLICATIONS: [0001] This patent application is a continuation-in-part patent application of: U.S. Ser. No. 11/655,441 filed on Jan. 19, 2007 and entitled SUPERCHARGED INTERNAL COMBUSTION ENGINE SYSTEM; U.S. Ser. No. 11/443,424 filed on May 29, 2006 and entitled SUPERCHARGED INTERNAL COMBUSTION ENGINE; and U.S. Ser. No. 11/389,795 filed on Mar. 27, 2006 and entitled SUPERCHARGED INTERNAL COMBUSTION ENGINE, the entire contents of all of which are hereby expressly incorporated by reference. FIELD OF THE INVENTION [0002] This invention relates generally to supercharged internal combustion engines and, more particularly, to compressors for superchargers capable of fast response to engine demand and delivering high boost during low engine speed. BACKGROUND OF THE INVENTION [0003] Turbocharging of Internal Combustion Engines: One of the long-term goals of the automotive manufacturers is to reduce fuel consumption and emissions of modem automotive vehicles powered by internal combustion engines (ICE) while increasing engine efficiency. One approach to reaching this goal is reducing the ICE displacement. However, smaller engines having reduced swept volume typically exhibit insufficient power and torque when operating with normal aspiration. This problem can be remedied by supercharging. It is well known in the art that ICE power output increases with increased weight of air ingested into engine cylinders and available for combustion. Weight of intake air ingested into engine cylinders can be increased by either (1) increasing the pressure of intake air beyond what can be accomplished by natural aspiration or by (2) reducing the temperature of intake air or by (3) a combination of (1) and (2). A supercharged ICE, therefore, receives combustion air with higher density than a normally aspirated ICE. As a result, supercharging allows generating increased power from an engine of a given displacement or, generating a given power output from an engine of smaller size, weight, cost, and emissions. In addition, reduced charge temperature is known to reduce ICE emissions by decreasing charge pre-ignition also known as knocking. [0004] One commonly used type of a supercharger is the exhaust-gas turbocharger which typically includes a turbine and a centrifugal compressor on a common shaft. The turbine is rotated by exhaust gases from the engine and spins the compressor. The compressor receives intake air, compresses it, and supplies it to ICE combustion chamber(s). Turbochargers provide the advantages of relatively smooth transition from natural aspiration to supercharged operation while utilizing some of the residual energy of hot exhaust gas, which would otherwise be largely wasted. The challenges of constructing a turbocharged ICE include: 1) reducing as much as possible the response time lag, 2) broadening of the compressor working regime, and 3) reducing the exposure of compressor impeller to high temperatures and stresses. Information relevant to attempts to overcome these challenges and the disadvantages of such attempts are described below. [0005] A turbocharged ICE is susceptible to a slow response time known as the “turbo lag” which is caused by the low pressure and low quantity of exhaust gases that are available to operate the turbine at low engine speeds. This translates to insufficient quantity of intake air delivered to the engine and results in insufficient torque at low engine speeds. The turbo-lag problem may be corrected in-part by the use of a variable nozzle turbine, which alters the cross-sectional area through which the exhaust gas flows in accordance with engine speed. However, this approach adds complexity and cost while reducing reliability. Another approach to reducing the turbo lag may use one or more jets of air injected onto the compressor wheel of a turbocharger as disclosed, for example, by Williams et al. in U.S. Pat. No. 3,190,068. Such air jets may be directed generally onto the vanes of the compressor wheel so as to transfer a part of their momentum to the wheel and thus accelerate the rotational speed of the compressor. Air injected in this manner becomes a part of the intake air ingested by the engine. Yet another approach may use air jets injected into the diffuser part of the compressor as disclosed by Schegk in U.S. Pat. No. 5,461,860, the entire contents of which is hereby expressly incorporated by reference. Neither said Williams nor said Schegk disclose injection of cold air into compressor housing or compressor components. [0006] Performance of a turbocharger compressor is often described in terms of a characteristic diagram which defines the working range of the compressor by plotting the ratio of compressor output pressure to its input pressure as a function of the air mass throughput through the compressor. The compressor working range in the characteristic diagram is limited by a so-called “surge limit.” The surge limit represents a characteristic curve which curbs the output of the compressor in the regime of combined low mass throughputs and a high output pressure. This regime corresponds to an ICE operating at high load and a low rotational speed. With the compressor operating close to the surge limit, local zones of detached flow may be formed, which may result in periodic pulsation of the flow, change in the flow direction and acoustic noise. To increase the operating range of the compressor in the regime of high-loads and low-speeds it is desirable to shift the surge limit towards lower mass throughputs. The surge limit may be favorably shifted by means of characteristic-diagram stabilization measures such as a bypass which bridges compressor outflow port and inflow port. In particular, the bypass returns part of the compressor output flow into the compressor the inflow port and directs it on the compressor-impeller inlet edge as disclosed, for example, by Sumser et al. in U.S. Pat. No. 6,813,887 the entire contents of which is hereby expressly incorporated by reference. If the compressor operates close to the surge limit, the bypass allows recirculation of a predetermined portion of the compressor output stream back to the compressor inflow port. Sumser also discloses an ICE having an auxiliary air feed which supplies auxiliary air at ambient temperature through an injection opening in a wall of the compressor inlet and directs it into the flow-facing region of the compressor wheel. Auxiliary air injected in this manner influences the surge limit in favor of a regime with lower mass throughputs and high compressor pressure ratio. As a result, compressor working range is broadened. Furthermore, injected auxiliary air beneficially drives the compressor impeller, thereby helping the turbocharger to accelerate to its normal operating speed range. As a result, high charging pressures may be attained more rapidly, the undesirable turbo lag is reduced, and the turbocharged ICE may accelerate from low speed in a rapid, smooth manner. However, said Sumser does not disclose injection of cold air into compressor housing or compressor components. [0007] Experience shows that when turbocharger delivers high supercharging pressures, the compressor components experience high thermal loading. This may necessitate that such components are either fabricated from high-temperature materials, which are costly and difficult to machine or that such components are actively cooled, which has limited effect and adds complexity. This problem may be alleviated by cooling the air recirculated via a bypass from the compressor outflow port back to the compressor inflow port as disclosed by Scheinert in U.S. Pat. No. 7,021,058 the entire contents of which is hereby expressly incorporated by reference. In particular, Scheinert discloses a temperature reducing unit comprising a diffuser in a form of an expansion duct employed to cool the recirculated air before it is directed onto compressor wheel. However, temperature reduction achievable by Scheinert's temperature reducing unit is very limited. [0008] Vortex Tube for Cooling of ICE Intake Flow: Vortex tube is a well known cooling device in the art of refrigeration. Traditional vortex tube comprises a slender tube having one end closed except for a small a central opening and the other end plugged except for an annular opening which may be adjusted in size for flow control, see FIG. 1 . A stream of high-pressure air (or other suitable gas) is injected through an inlet port tangentially into the tube in the proximity of the central opening. Resulting vortex flow pattern inside the tube separates the input air stream into a relatively hot air stream which exits through the annular opening and a relatively cold air stream which exits through the central opening and the cold outlet port. Relative flow rates and temperatures of these two streams are typically adjustable by controlling the flow of the hot exhaust stream. See, for example, article entitled “The Vortex Tube as a Classic Thermodynamic Refrigeration Cycle,” by B. K. Ahlbom et al., published in Journal of Applied Physics, Volume 88, Number 6, pp. 3645-3653, Sep. 15, 2000. A variant of the traditional vortex tube suitable for generating only a cold output stream can be produced by entirely closing one of the tube ends combined with active cooling of the tube exterior surface such as shown in FIGS. 2A and 2B and disclosed, for example, by Zerr in U.S. Pat. No. 4,612,646. Suitable cooling may be provided by a cooling jacket which may envelop the exterior surface of the tube. Suitable coolants may be provided in liquid or gaseous form. The exterior surface of the tube can be further provided with surface extensions to facilitate improved heat transfer as disclosed, for example, by Tunkel et al. in U.S. Pat. No. 5,911,740. [0009] Lindberg et al. in U.S. Pat. No. 6,247,460 discloses an ICE having a vortex tube for cooling intake air. Lindbergh's vortex tube generates both cold and hot outputs with only the cold output supplied to ICE intake. All of the intake air flows through the vortex tube at all times. When used on a supercharged ICE, the pressure drop of intake air inside the vortex tube robs the ICE of the pressure boost provided by the supercharger and wastes much of the supercharger output into vortex tube hot flow. Similarly, when used on a naturally aspirated ICE, the vortex tube impedes intake air flow thereby significantly reducing the intake air pressure. In each case the benefit of providing cooler air to the ICE is accomplished at the expense of reducing the intake air pressure. In particular, data of some vortex tube manufacturers suggests that the pressure ratio between vortex tube inlet port and its cold outlet port should be at least 2.4. See, for example, Catalog No. 21, page 102, published by Exair Corporation, Cincinnati, Ohio. Since cooling of the intake air and reducing its pressure have opposite effects on air density, the net benefit of Lindberg's apparatus, if any, is rather limited. Holman et al. in the U.S. Pat. No. 6,895, 752 discloses a turbocharged ICE with an exhaust gas recirculation (EGR) system wherein ICE exhaust is directed to a vortex tube to generate a cooler flow and a hoter flow. The cooler flow is directed to ICE intake to recirculate part of the exhaust gas while the hot flow may be exhausted from the ICE in a conventional manner. [0010] In summary, prior art does not teach a turbocharged ICE system that is effective during the conditions of high torque and low engine speed, has a fast response to power demand, is simple, economical, avoids exposing compressor components to excessive temperatures, and reduces susceptibility to charge pre-ignition. Furthermore, the prior art does not teach a turbocharged ICE system where turbocharger operation is augmented by injection of cold air from a vortex tube. Moreover, the prior art does not teach a turbocharged ICE system where turbocharger compressor is cooled by cold air from a vortex tube. It is against this background that the significant improvements and advancements of the present invention have taken place. SUMMARY OF THE INVENTION [0011] The present invention provides a turbocharged ICE system wherein the turbocharger assembly comprises a vortex tube that supplies cold, dense air to the ICE intake. When such cold air is supplied to a turbocharger compressor in the ICE intake, it may beneficially increase the compressor surge limit, cool the compressor blades, and accelerate the compressor speed. Faster compressor speed is conducive to generating higher charge pressure. In addition to increasing the charge pressure, injection of cold dense air may cool the engine intake air, which may further increase the weight of ICE charge and thus enable the ICE to produce more output power. Injection of cold air in the form of high-velocity jet onto compressor impeller may also enhance transfer of kinetic energy from the jet to the impeller and promote further increase in impeller speed. Cold air from the vortex tube may be also injected into the flow of intake air downstream of the compressor impeller either into the compressor diffuser or into the engine intake duct. In particular, cold air may be injected into the intake duct as one or more high velocity jets arranged to entrain and pump engine intake air, thereby increasing charge air density both by compression and by cooling. Suitable cold air injector may be a nozzle adapted for subsonic, sonic, or supersonic flow regime. Furthermore, the injector in the intake duct may be a driving nozzle which may also include lobes to enhance mixing. The compressed air for operation of the vortex tube may be obtained from the turbocharger compressor output flow or it may it may be supplied from an auxiliary air source. Suitable auxiliary air source may include an auxiliary compressor and/or an air tank. [0012] The vortex tube for use with the subject invention is preferably adapted for generation of cold output stream only. Such a vortex tube may include a cooling jacket or a heat exchanger which transfers heat from the vortex tube to either liquid coolant, gas coolant, air, ballast structure, or a phase change material (PCM). The turbocharged ICE system of the subject invention may further include means for regulating the flow and/or pressure of high-pressure air fed to the vortex tube and thereby regulating the air cooling action. In addition, the turbocharged ICE system may include means for sensing ICE power demand and appropriately controlling the operation of the vortex tube and the turbocharger to supercharge the ICE in response to demand. [0013] In one preferred embodiment of the present invention particularly useful for transient operation during times of increasing ICE power output, compressed air from an auxiliary compressed air source is cooled in a vortex tube and injected into the housing of a turbocharger compressor. In particular, cold air may be injected into the flow facing region of the compressor impeller, and/or onto the edge of impelled blade, and/or into the compressor diffuser. This embodiment is particularly useful for improving the performance of a compressor during periods of increasing ICE power demand. In another preferred embodiment of the present invention, a portion of the supercharging compressor output compressed air stream is cooled in a vortex tube and injected back into the housing of a turbocharger compressor. This embodiment is particularly suitable for turbochargers having high compression ratio (including multiple stage turbochargers) where it is useful for substantially continuous improvement of compressor performance such as may be desired during generally continuous operation. In yet another embodiment, compressed air from an auxiliary compressed air source is cooled in a vortex tube and injected into the engine intake duct downstream of the compressor. Cold air injected into the intake duct may be mixed with intake air from the exhaust-gas turbocharger. The resulting intake air mixture is colder and denser, which results in increased weight of ICE charge. Furthermore, the injector may be a driving nozzle arranged to pump intake air into the engine combustion chamber. In a still another embodiment, compressed air from an auxiliary compressed air source is cooled in a vortex tube and it is used to operate an ejector arranged to pump intake air at times of increasing ICE load. When the ejector is not needed, intake air may bypass the ejector through a bypass duct. The auxiliary compressed air source may also include an auxiliary compressor and/or an air tank for providing compressed air to the vortex tube. The auxiliary compressor may be driven by the ICE output shaft, vehicle drive train, an electric motor, or by other suitable means. The auxiliary compressor may be adapted to be preferentially engaged during periods of low ICE load and/or to recover kinetic energy during vehicle deceleration. A variant of the invention includes a vortex tube having a cooling jacket filled with PCM. During vortex tube operation, high-temperature air generated inside the vortex tube is cooled by transferring its heat into the PCM. Between supercharging events, heat is removed from the PCM and transferred to liquid coolant, gas coolant, or air. Another variant of the vortex tube may include a provision for storing heat as a sensible heat in vortex tube ballast structure. [0014] Accordingly, it is an object of the present invention to provide a turbocharged ICE system which may generate a high volume of intake air flow at high pressure during the conditions of high load demand and relatively low engine speeds. The turbocharged ICE system of the present invention is simple, lightweight, and inexpensive to manufacture which makes it suitable for large volume production of automotive vehicles. [0015] It is another object of the invention to provide a turbocharger assembly that has a fast response to output demand conditions. [0016] It is still another object of the invention to reduce the temperature of ICE intake air delivered by a turbocharger. [0017] It is yet another object of the invention to cool a supercharger compressor especially during conditions of high loading. [0018] It is yet further object of the invention to pump intake air into an internal combustion engine. [0019] It is a further object of the invention to beneficially broaden the operating range of a turbocharger compressor. [0020] It is still further object of the invention to beneficially shift the surge limit in a turbocharger compressor at times of high load and low speed of associated engine. [0021] These and other objects of the present invention will become apparent upon a reading of the following specification and claims. BRIEF DESCRIPTION OF THE DRAWINGS [0022] FIG. 1 is a cross-sectional view of a vortex tube of prior art suitable for concurrent generation of hot and cold output streams. [0023] FIG. 2A is a cross-sectional view of a vortex tube of prior art suitable for generation of cold output stream only. [0024] FIG. 2B is a cross-sectional view of an alternative vortex tube of prior art suitabled for generation of cold output stream only. [0025] FIG. 3 is a schematic view of a turbocharged ICE system in accordance with a one embodiment of the subject invention. [0026] FIG. 4A is a cross-sectional view of a centrifugal compressor parallel to the plane of impeller rotation. [0027] FIG. 4B is a cross-sectional view of a centrifugal compressor perpendicular to the plane of impeller rotation. [0028] FIG. 5A is a cross-sectional view of a vortex tube adapted for generation of cold output stream only while rejecting heat into a phase change material (PCM). [0029] FIG. 5B is a cross-sectional view of a vortex tube adapted for generation of cold output stream only while rejecting heat into a ballast structure. [0030] FIG. 6 is a schematic view of a turbocharged ICE system in accordance with another embodiment of the subject invention. [0031] FIG. 7 is a schematic view of a turbocharged ICE system in accordance with yet another embodiment of the subject invention. [0032] FIG. 8 is a schematic view of a turbocharged ICE system in accordance with still another embodiment of the subject invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0033] Selected embodiments of the present invention will now be explained with reference to drawings. In the drawings, identical components are provided with identical reference symbols. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the present invention are merely exemplary in nature and are in no way intended to limit the invention, its application, or uses. [0034] Referring to FIG. 3 , there is shown a turbocharged internal combustion engine (ICE) system 10 in accordance with one embodiment of the subject invention. The ICE system 10 comprises an ICE 20 and a turbocharger assembly 100 . The ICE 20 has at least one combustion chamber fluidly coupled to an intake duct 26 to receive intake air therefrom and to an exhaust duct 46 to discharge exhaust gases thereinto. The type of ICE 20 may be either a compression ignition (diesel), a fuel injected spark ignition, carbureted spark ignition, or homogeneous charge compression ignition (HCCI) also known as controlled auto-ignition (CAI). Furthermore, the ICE 20 may also include an output shaft 28 and a torque sensor 30 for sensing ICE output torque. If the ICE system 10 is installed in an automotive vehicle, the output shaft 28 may provide power to a transmission 74 , which in turn, may spin a drive shaft 48 to operate vehicle wheels 64 via differential 82 and axle 52 as is commonly practiced in the art. [0035] The turbocharger assembly 100 comprises an exhaust gas turbocharger 162 , a vortex tube 120 , a high-pressure air supply line 138 , control valve 132 , pressure regulator 130 , interconnecting lines 136 and 137 , and an air feed line 148 . The exhaust-gas turbocharger 162 further comprises a compressor 135 having an impeller 123 inside a compressor housing 144 and a turbine 182 having a turbine wheel 170 inside a turbine housing 188 . The impeller 123 and the turbine wheel 170 are mounted on a common shaft 166 . The turbine 182 is fluidly connected to the exhaust duct 46 and adapted to receive therethrough exhaust gases from the ICE 20 to spin the turbine wheel 170 . The compressor housing 144 has an inflow port 158 fluidly connected to inflow duct 126 and an outflow port 174 fluidly connected to intake duct 26 . The compressor 135 is adapted to receive intake air at one pressure through inflow port 158 , to compress it to a higher pressure, and to deliver compressed intake air through outflow port 174 into the intake duct 26 and therethrough to the ICE 20 . The turbocharger assembly 100 may also include an intercooler 168 installed in the intake duct 26 to cool the intake air prior to delivery to the ICE 20 . The turbocharger assembly 100 may also include a speed sensor 114 for sensing rotational speed of the turbocharger 162 . The line 138 is fluidly connected to an auxiliary source of compressed air which may be external to the ICE system 10 . External auxiliary source of compressed air may be an existing supply of compressed air in vehicles such as trucks, buses, earth moving equipment, and utility vehicles. Such an external auxiliary source of compressed air may include a conventional reciprocating or rotary type compressor, or the compressed air may be generated in ICE cylinders during vehicle braking, as for example, disclosed by Larson et al. in U.S. Pat. No. 6,922,997. If an external auxiliary source of compressed air is not used, the turbocharger assembly 100 may also include an auxiliary compressor 164 , compressor inlet line 176 , aftercooler 178 , check valve 180 , air tank 160 , and interconnecting lines 172 , 184 , and 186 . [0036] The auxiliary compressor 164 may be of any suitable type and it may have one or more stages to obtain a desired level of compression. Suction port of the auxiliary compressor 164 is fluidly coupled by the inlet line 176 to the intake duct 126 and it is adapted for drawing a portion of intake air therefrom. The auxiliary compressor 164 is preferably driven mechanically, hydraulically or by other suitable means. For example, the auxiliary compressor 164 may be driven mechanically either from the output shaft 28 , or the crankshaft of the ICE 20 , or from the vehicle drive shaft 48 . Suitable mechanical means may include 1) direct coupling and 2) a system of belt and pulleys. Suitable mechanical means may also comprise a clutch 157 or an off-loader valve (not shown) that allows engaging the compressor 164 in accordance with predetermined conditions as it will be described below. Alternatively, the auxiliary compressor 164 may be driven by an electric motor. Discharge port of the auxiliary compressor 164 is fluidly coupled to the air tank 160 via the aftercooler 178 , the check valve 180 and the interconnecting lines 172 , 184 and 186 . [0037] The aftercooler 178 may be of the same general type used in conventional compressed air systems to remove the heat of compression from the air downstream of a compressor. The aftercooler 178 may be cooled by ambient air or by ICE coolant or other suitable means. The check valve 180 prevents a backflow of high-pressure air from the air tank 160 into the compressor 164 when the compressor is not operating. The line 184 may also include a water separator to remove water condensate from cooled air flow. The design and choice of materials for the air tank 160 are preferably selected to reduce the likelihood of tank rupture in the event of vehicle collision and/or fire. The air tank 160 may also include a pressure sensor which may be used to determine the amount of air stored. This information may be used in controlling the operation of the auxiliary compressor 164 of turbocharger assembly 100 , and it may be also made available to the operator of an associated automotive vehicle. [0038] The pressure regulator 130 is fluidly connected to the air tank 160 by means of the high-pressure line 138 . Preferably, the pressure regulator 130 is remotely controllable in a manner that allows remotely controlling the pressure level in the line 136 . Suitable pressure regulators that are remotely controllable either electrically, pneumatically, hydraulically, or mechanically are available commercially. The control valve 132 is fluidly connected to the pressure regulator 130 by means of the line 136 and to the inlet port 116 of vortex tube 120 by means of the line 137 . The control valve 132 may be of on/off type and preferably have a very low flow impedance. Alternatively, the control valve 132 may be adapted for substantially smooth regulation of mass flow rate of compressed air in which case the pressure regulator 130 may become unnecessary. [0039] The vortex tube 120 is preferably of the type adapted for generation of cold air only such as shown in FIGS. 2A and 2B and described in connection therewith. The vortex tube 120 may have a cooling jacket (see FIGS. 2A and 2B ) which may be cooled by ICE coolant, or by ambient air, or by other suitable means. If ICE coolant is used, it is preferably supplied at a temperature between 5 and 30 degrees Centigrade. Preferably, the body of the vortex tube 120 is maintained at a temperature above zero degrees Centigrade to prevent moisture contained in the air entering the tube from freezing onto tube walls. The design of vortex tube 120 may also include a provision to reduce susceptibility to plugging by ice formed from the residual moisture in the inlet air. Suitable non-freezing vortex tube has been disclosed by Tunkel at al. in U.S. Pat. No. 6,289,679. The inlet port 116 of the vortex tube 120 is fluidly connected to the air tank 160 via the pressure regulator 130 , valve 132 , and the interconnecting lines 136 , 137 , and 138 . The cold outlet 124 port of the vortex tube 120 is fluidly connected by the air feed line 148 to the compressor housing 144 . The compressor housing 144 is adapted to receive cold air from the feed line 148 and inject it as a jet 146 into the housing 144 via one or more injectors 142 . An alternative vortex tube for use with the subject invention may have a conventional design for concurrent generation of hot and cold outlet stream such as shown in FIG. 1 and described in connection therewith. In this case, the hot outlet stream may be released from the vortex tube through an appropriate flow impeding device (such as a control valve) so that the cold and hot outlet streams are desirably balanced in volume and a desired cold stream temperature and flow rate are obtained. The ICE system 10 preferably includes an electronic control unit (ECU) 194 . Suitable ECU may be comprised of a central processing unit, a read-only memory, random access memory, input and output ports, and the like. The ECU 194 may be configured to receive signals from sensors in the ICE system 10 , to determine whether certain predetermined conditions exist based on the measured parameters and generate signals to control the operation of the turbocharger assembly 100 . [0040] Referring now to FIGS. 4A and 4B , cold air from the air feed line 148 may be injected into the compressor housing 144 through one or more injectors 142 a to form a jet 146 a directed into the flow facing portion of the impeller 123 as disclosed by the above noted Sumser. If more than one injector 142 a is used, they may be circumferentially placed in the inflow port 158 . Alternatively, cold air stream from the air feed line 148 may be injected through one or more injectors 142 b to form a jet or jets 146 b directed upstream of the axial end side of the compressor impeller blades 150 and/or one or more injectors 142 c to form a jet or jets 146 c directed generally radially at the level of the compressor impeller blades 150 as disclosed by the above noted Scheinert. As a yet another alternative, cold air stream from the air feed line 148 may be injected through one or more injectors 142 d to form a jet or jets 146 d directed at the downstream edge of the compressor impeller blades 150 as disclosed by Bucher in U.S. Pat. No. 4,696,165. As a still another alternative, if the compressor 135 has a vaned diffuser 190 , cold air stream from the air feed line 148 may be injected through one or more injectors 142 e to form a jet or jets 146 e directed between diffuser blades 196 and into the diffuser inlet as disclosed by the above noted Schegk. In each case, suitable openings for injecting cold air into the compressor housing may be conducive to generating subsonic flow, sonic flow, or supersonic flow. For example, the cold air injector 142 a through 142 e may be a subsonic, sonic or supersonic nozzle. [0041] Referring now again to FIG. 3 , during normal operation of the supercharged ICE system 10 , intake air stream 32 is drawn into the turbocharger 100 , passes therethrough and it is fed as an intake air stream 32 ″ into ICE 20 where it is combusted with suitable fuel. Exhaust gas stream 92 flows from the ICE 20 through the exhaust duct 46 into the turbine 182 and it exists the turbine 182 as an exhaust gas stream 92 ′. When the ICE 20 operates at reduced load, the amount of exhaust gases in the exhaust stream 92 is limited and the turbocharger 162 may operate at low or moderate rotational speed. Under these conditions, the compressor 135 may generate low or insignificant compression while the engine 20 may be provided with adequate quantity of intake air. Therefore, the control valve 132 may be closed. The auxiliary compressor 164 may be operated concurrently as it may be necessary to maintain the air pressure inside the tank 160 within predetermined limits. In particular, the auxiliary compressor 164 may draw air (preferably free of dust and solid particulates) from the inflow duct 126 through the inlet line 176 and compress it to a desired pressure. Preferred output pressure of auxiliary compressor 164 is between 50 and 300 psi. As an alternative, the auxiliary compressor 164 may draw filtered air from ambient atmosphere or other suitable source. Output of the auxiliary compressor 164 is fed through the line 172 into the aftercooler 178 where the heat of compression is largely removed, and through the line 184 , check valve 180 and line 186 into the air tank 160 . The air tank 160 may be equipped with a pressure switch having one higher setting and one lower setting. The pressure switch may be operatively connected to the controls of the auxiliary compressor 164 (and/or to the clutch 157 , if used) so that the auxiliary compressor 164 may be operated to maintain the pressure in the air tank 160 between predetermined limits. Alternatively, the auxiliary compressor 164 may be equipped with an unloader valve which automatically relieves the auxiliary compressor 164 of the pumping load when the air tank 160 is charged to a predetermined pressure. The auxiliary compressor 164 may be engaged in a smooth and/or gradual manner to avoid imposing abrupt load on its source of motive power. To avoid excessive or unnecessary power drain on the ICE 20 , operation of the auxiliary compressor 164 may be restricted or prohibited during periods of high power demand on the ICE. For example, if the air tank 160 is charged to a level above a predetermined tank charge level value, operation of the auxiliary compressor 164 may be allowed only when the ICE output torque (as, for example, sensed by the torque sensor 30 or by other suitable means) is less than a predetermined ICE output torque value. As another example, if the air tank 160 is charged to a level above a predetermined tank charge level value, operation of the auxiliary compressor 164 may be allowed only when the torque in the vehicle drive shaft 48 is less than a predetermined vehicle drive shaft torque value. Such a predetermined vehicle drive shaft torque value may have a negative sign. The auxiliary compressor 164 may be also engaged in a manner which allows recovery of kinetic energy from the motion of associated automotive vehicle. For example, if the air tank 160 is charged to a level above a predetermined tank charge level value, operation of the auxiliary compressor 164 may be allowed only when vehicle brakes are applied. In this fashion, a significant portion of the vehicle kinetic energy otherwise wasted in braking may be recovered. [0042] When the demand for output power of the ICE 20 is increased, so is the demand for intake air. At that instant, the speed of the turbocharger 162 may be relatively low and the turbocharger may have to accelerate to meet the ICE intake air demand. This condition is detected as described below and remedied by appropriately setting the pressure regulator 130 and by opening the control valve 132 . As a result, the pressure regulator 130 regulates the pressure of compressed air it receives from the high-pressure supply line 138 and flows regulated compressed air at a predetermined pressure p 1 into the line 136 . The control valve 132 and lines 136 , 137 , and 148 are preferably constructed to have a very low impedance to air flow. Preferably, output pressure of the pressure regulator 130 is set so that the absolute pressure p 1 at the vortex tube inlet 116 is at least 2.4 times greater than the absolute pressure p 2 inside at the cold outlet port 124 . A preferred value for pressure ratio of p 1 /p 2 is between about 2.4 and about 8. Referenced art suggests that exceeding this range may cause undesirable flow shocks inside the vortex tube 120 (see, e.g., B. K. Ahlbom, supra). With the control valve 132 in an open position, compressed air from the air tank 160 forms a stream 110 which flows through the line 137 to the inlet port 116 of the vortex tube 120 . If the vortex tube shown in either FIG. 2A or 2 B is used, thermodynamic action inside the vortex tube deposits heat into the tube's cooling jacket and it cools the air inside the tube. Regardless of the vortex tube style, cold air exits the vortex tube 120 through the cold outlet port 124 , flows through the air feed line 148 into the compressor housing 144 via the injector 142 and it forms a jet 146 . [0043] Referring now again to FIGS. 4A and 4B , the injector 142 may be arranged in the configuration of injector 142 a , 142 b , 142 c , 142 d , and/or 142 e . One or more injectors may be used for each injector configuration. In particular, cold air stream from the air feed line 148 may be injected 1) through one or more injectors 142 a to form one or more jets 146 a directed into the flow facing portion of the impeller 123 and/or 2) through one or more injectors 142 b to form one or more jets 146 b directed upstream of the axial end side of the compressor impeller blades 150 and/or 3) through one or more injectors 142 c to form one or more jets 146 c directed onto the compressor impeller blades 150 and/or 4) through one or more injectors 142 d to form one or more jets 146 d directed at the downstream edge of the compressor impeller blades 150 . The impeller 123 of compressor 135 is thus cooled by contact with injected cold air and the momentum of the injected air is in-part transferred to the impeller 123 , thereby accelerating its rotational speed. If the compressor 135 has a vaned diffuser 190 , cold air stream from line 148 may be injected through one or more injectors 142 e to form one or more jets 146 e directed between the diffuser blades 196 and into the diffuser inlet. The resulting jets 142 e entrain intake air in the diffuser and pump it into the intake duct 26 . Cold air injected through any of the injectors 142 a through 142 e is mixed with the intake air stream 32 and, as a result, cooler and denser air is delivered into the intake duct 26 . Air flowing through the intake duct 26 may be further cooled by the intercooler 168 prior to being delivered the combustion chambers of ICE 20 . Increased quantity of air available for combustion allows ICE 20 to generate more output power and greater quantity of exhaust gases in the exhaust gas stream 92 which, in turn, operates the turbine wheel 170 and allows it to further accelerate in rotational speed. [0044] Under typical driving conditions the periods of high-power demand on the ICE 20 are relatively short and (depending on vehicle driving conditions) may occur on the average only about 10% of the vehicle operating time. This means that the conditions requiring the turbocharger 100 to accelerate may be discontinuous and air from the air tank 160 may be discharged in an intermittent mode. For example, the ICE may operated in a supercharged mode for about 10% of the vehicle operating time. This may leave on the average about 90% of the vehicle operating time available for recharging the air tank 160 . [0045] At any time during the ICE operation, the ECU 194 may monitor one or more operating parameters of the ICE system 10 and regulate the mass flow rate of air through the vortex tube 120 by operatively controlling the pressure regulator 130 and the valve 132 according to predetermined conditions. Operating parameters monitored by the ECU 194 may include engine rotational speed, turbocharger rotational speed, engine output torque, fuel flow rate, vehicle speed, throttle opening (if throttle is used), and position of accelerator pedal. Other useful parameters monitored by the ECU may include ambient air pressure and temperature, intake air mass flow rate, and intake air pressure and temperature. The engine output torque value can be either directly measured (for example, the torque value can be the detection value of the torque sensor 30 ) or it can be inferred from other ICE parameters. In particular, it is well known that engine torque value can be estimated from one or more ICE parameters including intake air mass flow rate, spark timing, or combustion chamber pressure data as noted, for example, by T. Jaine et al. in “High-Frequency IMEP Estimation and Filtering for Torque-Based SI Engine Controls,” SAE paper number 2002-01-1276, published by the Society of Automotive Engineers, Inc., Warrendale, Pa. Alternatively to using an ECU with a central processing unit, various electrical, mechanical, electromechanical, hydraulic, and/or pneumatic control mechanisms may be used to operate the valve 132 and the pressure regulator 130 in response to predetermined conditions. It will be apparent to those skilled in the art from this disclosure that the precise structure and algorithms for the ECU can be any combination of hardware and software that will carry out the functions of the present invention. [0046] There is a variety of processes the ECU 194 may employ for controlling the operation of the turbocharger 100 . Preferably, the ECU repeatedly obtains and stores detection values of various sensors which may be processed to determine the state of ICE system 10 . Such sensors may include, but are not limited to ICE rotational speed, turbocharger rotational speed, position of accelerator pedal, throttle opening, fuel flow rate, vehicle speed, ICE output torque, air velocity in the intake duct 26 , air pressure in the line 137 , setting of the pressure regulator 130 , position of the control valve 132 , air pressure and temperature in the intake duct 126 , air pressure and temperature in ICE intake duct 26 , ambient air pressure and temperature, and pressure and temperature of exhaust gases in the exhaust duct 46 . The ECU 194 may be configured to increase the mass flow of cold air into the compressor housing 135 if simultaneously the turbocharger rotational speed value is less than a predetermined turbocharger rotational speed value and the ICE torque value is more than a predetermined ICE torque value. Accordingly, the ECU 194 may be configured to decrease the mass flow of cold air into the compressor housing 144 if simultaneously the turbocharger rotational speed value is more than a predetermined turbocharger rotational speed value and the ICE torque value is less than a predetermined ICE torque value. [0047] FIGS. 5A and 5B respectively show alternative vortex tubes 120 ′ and 120 ″ suitable for use with the subject invention. Referring now to FIG. 5A , the vortex tube 120 ′ comprises a tubular body 252 having two ends 214 and 215 opposite to each other. The first end 215 is entirely closed. The second end 214 is partially closed and has a central opening 244 leading to a cold outlet port 124 . An inlet port 116 for compressed air is installed in proximity of the second end 214 . The tubular body 252 is preferably constructed from a material with high thermal conductivity such as copper, copper alloys, aluminum and aluminum alloys. Exterior of the tubular body 252 is substantially surrounded by a cooling jacket 262 filled with phase change material (PCM) 218 . Suitable PCM may include stearin which is known to have a transition temperature in the range of 50-70 degrees Centigrade and certain fusible metals such as Wood's metal which is known to have a transition temperature around 70 degrees Centigrade or Field's metal which is known to have a transition temperature around 62 degrees Centigrade. The vortex tube 120 ′ may also include cooling fins 216 attached to the exterior surface of tubular body 252 . Suitable cooling fins are preferably made of material with high thermal conductivity and are in a good thermal contact with each the tubular body 252 and the PCM 218 . In one embodiment, the cooling fins 216 may extend radially so as to protrude through the cooling jacket 262 (as shown in FIG. 5A ). Tip portions 286 of cooling fins 216 may be in a thermal communication with a cooling fluid which may be a gas such as air or a liquid such as engine cooling fluid. [0048] The vortex tube 120 ′ is suitable for operation in two modes: 1) a cooling mode and 2) a thermal recovery mode. At the beginning of the cooling mode, the PCM 218 is substantially in a solid form. Compressed air stream 110 at an initial pressure and temperature is injected through the inlet port 116 tangentially into the interior of the tubular body 252 where it forms a vortex flow pattern in a manner already described in connection with FIGS. 1 , 2 A and 2 B. Furthermore, the injected air is cooled and it forms a cold air stream 151 having reduced temperature and pressure. The cold air stream 151 exits the vortex tube 120 ′ through the central opening 244 leading to the cold outlet port 124 . The vortex flow deposits heat into the tubular body 252 . The tubular body 252 further conducts the heat with the aid of the cooling fins 216 into the PCM 218 and causes it to gradually melt. When the PCM 218 is substantially melted, the cooling mode may be terminated, the flow of compressed air stream 110 is stopped, and the thermal recovery mode may be initiated. In the thermal recovery mode of operation, heat stored in the PCM 218 may be removed from the vortex tube 120 ′ by conducting it through the cooling fins 216 to a coolant in thermal communication with the tip portions 286 . When the PCM 218 has been substantially transformed back into solid form, the thermal recovery mode of operation may be concluded and the vortex tube 120 ′ may be ready for operation in the cooling mode. [0049] The vortex tube 120 ″ shown in FIG. 5B uses a heat ballast structure 212 to store thermal energy as sensible heat. The ballast structure 212 is preferably made of material having high thermal conductivity, such as aluminum alloys or copper and it is placed in a good thermal communication with the tubular body 252 ′. Furthermore, the ballast structure 212 may include fins 228 . In some variants of the invention, the ballast structure 212 and the tubular body 252 ′ may be formed as a single component. The vortex tube 120 ″ is suitable for operation in two modes: 1) a cooling mode and 2) a thermal recovery mode. At the beginning of the cooling mode, the temperature of the ballast structure 212 is less than a predetermined ballast lower temperature value. As the vortex tube 120 ″ cools injected compressed air, the tubular body 252 ′ conducts heat to the ballast structure 212 causing it to gradually heat up. When the temperature of the ballast structure 212 reaches a predetermined ballast upper temperature value, the cooling mode may be terminated, the flow of compressed air stream 110 may be stopped, and the thermal recovery mode may be initiated. In the thermal recovery mode of operation, heat stored in the ballast structure 212 may be removed from the vortex tube 120 ″ by conducting it through the cooling fins 228 to a coolant in thermal communication with the cooling fins. When the temperature of the ballast structure 212 becomes less than a predetermined ballast lower temperature value, the thermal recovery mode of operation may be concluded and the vortex tube 120 ″ may be ready for operation in the cooling mode. As already noted, the cooling fins of the vortex tubes 120 ′ and 120 ″ may be cooled by air. If the ICE 20 is water cooled and it has a radiator with a fan that induces air into the radiator, or if the ICE 20 is air cooled and it has a fan that induces air over the engine, the vortex tube may be placed so that it may receive a part of the air flow induced by the fan. If the ICE is used in a vehicle, the vortex tube 120 ′ or 120 ″ may be exposed to vehicle slipstream air and be cooled by it. [0050] Referring now to FIG. 6 , there is shown a turbocharged ICE system 11 in accordance with another embodiment of the subject invention which is particularly suitable for turbochargers with high compression ratio and for substantially continuous operation. The ICE system 11 comprises a turbocharger assembly 101 which is essentially the same as the turbocharger assembly 100 except that the source of compressed air for operation of the vortex tube 120 in this embodiment may be the compressor 135 . Furthermore, the pressure regulator 130 may not be used. In particular, the inlet port 116 of vortex tube 120 is fluidly coupled to the intake duct 26 by means of the line 136 ′. The line 136 ′ is fluidly connected to the intake duct 26 preferably downstream of the intercooler 168 (if intercooler is used). The compressor 135 used in this embodiment should be capable for generating sufficiently high pressure ratio to operate the vortex tube 120 . Preferably, the compressor pressure ratio is at least 2.4. Alternatively, a second compressor 128 (shown in broken line) may be placed in series with and downstream of the compressor 135 . In such case, the line 136 ′ is preferably arranged to receive compressed air generated by the second compressor 128 . The injector 142 may be configured in the form of an injector 142 a , 142 b , 142 c , and/or 142 d as shown in FIGS. 4A and 4B and already described in connection therewith. The control valve 132 may be configured upstream of the vortex tube 120 (as shown in FIG. 6 ) or down stream of it (in line 148 ). In either case, the control valve 132 may be adapted for substantially smooth control of mass flow rate of cooled air to the injector 142 . If desirable, the air feed line 148 may be branched out and separate control valves may be configured on each branch to independently control delivery of cold air from the vortex tube 120 to the injectors 142 a , 142 b , 142 c , and/or 142 d. [0051] In operation, compressor 135 may receive intake air stream 32 , compress it to generate compressed intake air stream 32 ′ which may be compressed again by the second compressor 128 (if used) and feed it to the intercooler 168 thereby producing an intake air stream 32 ″ which may be then fed to the ICE 20 . Intake air may be combusted with suitable fuel in ICE 20 thereby generating an exhaust gas stream 92 which may be fed to the turbine 174 to spin the turbine wheel 170 , which in turn may spin the impeller 123 of compressor 135 . When injection of cold air into the housing 144 of compressor 135 is desired, the valve 132 may open at least partially and a portion of the intake air stream 32 ″ may be allowed to flow into the line 136 ′, through the control valve 132 and into the line 137 , thereby forming a compressed air stream 110 ′. The air stream 110 ′ may flow through the inlet port 116 into the vortex tube 120 where it may be at least in-part cooled and then fed through the air feed line 148 into the housing 144 of compressor 135 . The turbocharger assembly 101 is particularly suitable for use with a turbocharger 162 having a compressor capable of generating high output pressure or an ICE system having multiple charge compressor stages. The turbocharger assembly 101 is also particularly suitable for substantially continuous operation whenever the pressure in the intake duct 26 is sufficient to operate a vortex tube. [0052] Referring now to FIG. 7 , there is shown a supercharged ICE system 12 in accordance with a yet another embodiment of the subject invention and having additional capability to provide dense intake air during periods of increasing power demand on the ICE 20 . The ICE system 12 comprises a turbocharger assembly 102 which is similar to the turbocharger assembly 100 except that the cold outlet port 124 of the vortex tube 120 is connected by the air feed line 148 ′ to the intake duct 26 rather than to the compressor housing 144 . Furthermore, the air feed line 148 ′ is preferably terminated inside the intake duct 26 with a driving nozzle 140 which is arranged to inject air in the general direction of the intake air stream 32 ″. One driving nozzle or several driving nozzles configured in parallel may be used. Suitable types of driving nozzles include a simple orifice, a subsonic nozzle, a sonic nozzle, supersonic nozzle, converging-diverging nozzle, and a lobed nozzle. Several configuration of a suitable supersonic nozzle are disclosed in the already noted Applicant's co-pending U.S. patent application Ser. No. 11/389,795. Preferred nozzle types include a converging-diverging nozzle which is conducive to generating supersonic flow and/or a lobed nozzle which is known for its good mixing characteristics. Note that a lobed nozzle may be operated in a supersonic flow regime. The nozzle 140 may also have a variable throat area for control of mass flow rate therethrough. Examples of suitable variable area driving nozzles have been disclosed in Applicant's U.S. Pat. No. 7,076,952 and the already noted co-pending U.S. patent application Ser. No. 11/655,441. To operate the driving nozzle 140 in the supersonic regime, the nozzle pressure ratio (=pressure in the line 148 ′/pressure in the intake duct 26 downstream of the nozzle) should be at least about 1.9. In addition, the flow rate and pressure of air fed in the line 137 into the inlet port 116 of vortex tube 120 should be properly selected so that the ratio of pressure at the vortex tube inlet 116 to the pressure at the cold outlet port 124 is maintained preferably between about 2.4 and about 8 as already stated above. [0053] In operation, when the ICE 20 is experiencing increasing power demand and the turbocharger 162 rotates at a speed insufficient to provide adequate amount of intake air to the ICE, the control valve 132 may open and cold air from the vortex tube 120 may be injected through the driving nozzle 140 into the intake duct 26 . The driving nozzle 140 generates a high velocity jet 146 ′ of cold air, which mixes with and entrains the intake air inside the intake duct 26 , and forces the intake air toward the ICE 20 . Kinetic energy of the flow downstream of the nozzle 140 is gradually converted into a potential (pressure) energy. As a result, intake air pressure inside the intake duct 26 downstream of the nozzle 140 is greater than the pressure upstream of the nozzle 140 , and the air temperature downstream of the nozzle 140 is lower than the temperature upstream of the nozzle 140 . Another words, injection of cold high-velocity air through the nozzle 140 increases the density of intake air fed to the combustion chamber of ICE 20 by a combination of compression and cooling. Cold air injection into the intake duct 26 may be also initiated whenever 1) the temperature of intake air downstream of the intercooler 168 exceeds a predetermined intake air temperature value, or 2) whenever the temperature of exhaust gas stream 92 exceeds a predetermined exhaust gas stream temperature value and the engine speed is less than a predetermined engine speed value, or whenever 3) the rate of temperature increase of intake air downstream of the intercooler 168 exceeds a predetermined rate of temperature increase of intake air value and the engine speed is less than a predetermined engine speed value, or 4) whenever the rate of increase of exhaust gas stream 92 temperature exceeds a predetermined rate of increase of exhaust gas stream 92 temperature value and the engine speed is less than a predetermined engine speed value. [0054] A portion of the intake duct 26 in the vicinity of the nozzle 140 may be formed into a venturi shaped diffuser duct 134 indicated in broken line in FIG. 7 . Such an arrangement enhances the capability of the nozzle 140 to pump intake air. The diffuser duct 134 preferably has a circular cross-section which is known for its low wall friction losses. However, other cross-sections including oval, ellipse, square, rectangle, polygonal shape, and alike may be also used. The diffuser duct 134 preferably has an upstream converging section, which may be followed by a straight middle section that is followed by a downstream divergent section. It should be noted that the nozzle 140 together with the venturi shaped diffuser duct 134 may be regarded as an ejector. Performance of such an ejector, namely its throughput and compression ratio depend (among other things) on the configuration of the nozzle 140 and of the diffuser 134 . For an ejector used in ICE supercharging application, it is desirable that the ejector (a) is capable of producing a compression ratio comparable to mechanical superchargers and turbochargers, namely at least about 1.3 and preferably at least about 1.5, (b) presents relatively low impedance to intake air flow when the ejector is not operating, and (c) is compact. Compactness is very important in automotive applications, especially in passenger automobiles, where the space in the engine compartment is very limited. In a practical sense, compactness of the ejector is mainly affected by the length of the diffuser duct. The above desirable attributes may be in mutual conflict because improving one may make it more challenging to meet the others. For example, to avoid undesirable detachment of flow from the diffuser wall, the walls of the diverging portion of the diffuser may be sloped at a very small angle (typically not exceeding about 4 degrees) with respect to the nominal flow direction. The length of the diffuser duct thus increases with the increasing transverse dimension (e.g., diameter) of the diffuser duct throat. One may increase the transverse dimension of a diffuser duct throat and thus beneficially reduce its impedance to intake air flow when the ejector is not operating (assuming that such flow passes through the ejector). However, a diffuser duct with a larger throat may make it more challenging to obtain a desired compression ratio. The approaches to making the ejector acceptably compact (short) while achieving acceptably high compression and acceptably low impedance to intake air flow may include: 1) use of lobed driving nozzle, 2) use of multiple driving nozzles, 3) use of multiple parallel ejectors, 4) use of a variable area diffuser, and 5) use of an ejector bypass duct. These will be now described in detail. [0055] 1) Lobed nozzles have been developed in aeronautics to improve mixing of the surrounding air with the high velocity jet produced by jet engines. Lobed nozzles may be operated either in a subsonic or supersonic regime. Suitable lobed nozzle is described in connection with jet engine design in a variety of technical publications including, for example, in “Parameter Effects on Mixer-Ejector Pumping Performance” by S. A. Skebe et al., paper number AIAA-88-0188 and in “Short Efficient Ejector Systems” by W. Pretz, Jr. et al., paper number AIAA-87-1837, both of which are available from the American Institute of Aeronautics and Astronautics, Washington, D.C., and in “Supersonic Nozzle Mixer Ejector,” by T. G. Tillman et al. published in Journal of Propulsion and Power, Volume 8, Number 2, March-April 1992, pages 513-519, and “Supersonic-Ejector Characteristics Using Petal Nozzle,” by A. K. Narayanan et al., published in Journal of Propulsion and Power, Volume 10, Number 5, September-October 1994, pages 742-744. The use of lobed nozzle in ejectors for ICE supercharging of has been disclosed by the Applicant in the already noted U.S. Pat. No. 7,076,952. The use of lobed driving nozzle may allow constructing a supercharging ejector with a substantially shorter diffuser than a comparable ejector with a single non-lobed driving nozzle. If the throat area of an associated diffuser duct is made about 25 to about 50 times the throat area of the corresponding lobed driving nozzle, the diffuser duct should have an acceptable impedance to intake air flow when the ejector is not operating. However, this condition may make it more challenging to obtain a desired compression ratio. [0056] 2) Ejector with multiple nozzles: An ejector having multiple driving nozzles discharging into one diffuser (as disclosed by the Applicant in the already noted U.S. Pat. No. 7,076,952) may be also made substantially (generally about 30%) shorter than a comparable ejector having a single nozzle without excessive degradation in performance. If the throat area of an associated diffuser duct is made about 25 to about 50 times the sum of the throat areas of the corresponding multiple driving nozzles, the diffuser duct should have an acceptable impedance to intake air flow when the ejector is not operating. However, this condition may make it more challenging to obtain a desired compression ratio. [0057] 3) Multiple parallel ejectors: Instead of one larger capacity (and comparably longer) ejector, one may use several smaller capacity (and comparably shorter) ejectors fluidly connected in parallel as disclosed by the Applicant in the already noted co-pending U.S. patent application Ser. No. 11/389,795. If for each of the smaller ejectors the throat area of an associated diffuser duct is made about 25 to about 50 times the throat area of the corresponding driving nozzle, the combination of parallel diffuser ducts should have an acceptable impedance to intake air flow when the ejector is not operating. However, this condition may make it more challenging to obtain a desired compression ratio. [0058] 4) The diffuser duct 134 may be also constructed as a variable area diffuser duct as disclosed by the Applicant in the already noted co-pending U.S. patent application Ser. No. 11/389,795. When the nozzle 140 injects high-velocity air into the variable area diffuser duct, the throat area of diffuser duct 134 may be set to between about 2 to about 25 times the throat area of the driving nozzle 140 (or the combined throat areas of multiple driving nozzles if multiple driving nozzles are used) to achieve high compression. In particular, the throat area of a variable area diffuser duct is preferably set to 3 to 15 times (and most preferably to 5 to 10 times) the throat area of the driving nozzle (or the combined throat areas of multiple driving nozzles if multiple driving nozzles are used). When the nozzle 140 is not operating, the throat area of the variable diffuser duct may be set to more than about 25 times (and preferably more than 50 times) the area of the driving nozzle 140 (or the combined throat areas of multiple driving nozzles if multiple driving nozzles are used) to achieve acceptable impedance to intake air flow. [0059] 4) Ejector bypass duct. A bypass duct offers a convenient low impedance means for flowing at least a portion of intake air when the ejector is not operating. Referring now to FIG. 8 , there is shown a supercharged ICE system 13 in accordance with a still another embodiment of the subject invention and having additional capability to provide dense intake air during periods of increasing power demand on the ICE 20 . The ICE system 13 comprises a turbocharger assembly 103 which is essentially the same as the supercharger assembly 102 except that nozzle 140 and the diffuser duct 134 are now a part of an ejector pump 122 . In addition, the turbocharger assembly 103 includes a bypass duct 190 , which allows the flow of intake air from the compressor 135 to bypass the ejector pump 122 . The bypass duct 190 includes a bypass valve 188 for control of intake air passing therethrough. The ejector pump 122 may be practiced with multiple driving nozzles injecting high-velocity jet into a single diffuser duct. Alternatively, several ejector pumps 122 may be used in parallel. As another alternative, one or more lobed driving nozzles may be used. The driving nozzle 140 may be also a variable area nozzle. Regardless of the driving nozzle configuration, the throat area of diffuser duct 134 may be made between about 2 to about 25 times the throat area of the driving nozzle 140 (or the combined throat areas of multiple driving nozzles if multiple driving nozzles are used) to achieve high compression. In particular, the throat area of the diffuser duct 134 is preferably made 3 to 15 times (and most preferably to 5 to 10 times) the throat area of the driving nozzle (or combined throat area of multiple driving nozzles if multiple driving nozzles are used). Three Penberthy ejectors model numbers GL-½, GL-¾, and GL-1¼″ (made by Penberthy Inc., Prophetstown, Ill.) with the throat areas of the diffuser ducts respectively being about 7.2 times, 7.5 times, and 6.3 times the throat areas of their respective driving nozzles were tested and showed acceptable compression and pumping performance. [0060] The bypass valve 188 may be formed as a check valve that closes automatically whenever the pressure downstream of the ejector 122 significantly exceeds the pressure upstream of the ejector 122 . Alternatively, the bypass valve 188 may an actuated valve of a suitable type (e.g., gate valve, poppet valve, damper valve, or a butterfly valve) operated by the ECU 194 . For example, the ECU 194 may close the bypass valve 188 whenever the mass flow through the driving nozzle 140 exceeds a predetermined mass flow value. Conversely, the ECU 194 may open the bypass valve 188 whenever the mass flow through driving nozzle 140 is below a predetermined mass flow value. If the valve 188 is an actuated valve, its closing and opening rate can be coordinated with the value of mass flow rate of air through nozzle 140 to produce a substantially smooth variation in air density at the ICE intake passage 26 . This approach is intended to avoid undesirably abrupt changes in ICE power output. Suitably precise control of valve 188 may be accomplished, for example, by actuating the valve 188 by a stepping motor. In operation, when it is not desirable to flow cold air through nozzle 140 the control valve 132 may be closed. Concurrently, the bypass valve 188 may be in an open position and intake air may flow primarily through the bypass duct 190 . When injection of cold air through nozzle 140 is desired, the control valve 132 may be open, the ejector pump 122 may be operated and the bypass valve 188 may be closed. [0061] It will be appreciated that the present invention can be implemented with a variety of ICE of either reciprocating type or rotary type. The ICE can have any number of combustion chambers. Features of the various embodiments may be combined in any suitable manner. The turbocharger assembly 100 , 101 , 102 , and 103 may be practiced with any type of a compressor 135 having an impeller 123 , including a turbo-compressor driven by an exhaust gas turbine or by an electric motor. The compressor 135 may have a radial or axial configuration. The turbocharger assembly 102 and 103 may be also practiced with the compressor 135 replaced by a suitable mechanical compressor including a Roots pump, screw compressor and a scroll compressor, or the turbocharger assembly may be practiced without the compressor 135 . [0062] An ICE system may be also incorporate several combined embodiments the turbocharger assembly of the subject invention and such embodiments may be activated according to predetermined conditions. For example, in response to increasing power demand and with the turbocharger 162 providing insufficient intake air, an ICE system may be initially configured in accordance with the turbocharger assembly 102 or 103 , wherein compressed air from an auxiliary source of compressed air is cooled in a vortex tube 120 and the resulting cold air injected into the intake duct 26 . After the injection of cold air into the intake duct 26 has been initiated, the ICE system may be configured in accordance with the turbocharger assembly 100 , wherein compressed air from an auxiliary source of compressed air is cooled in the vortex tube 120 and the resulting cold air injected into the compressor housing 144 where it may be used to favorably shift the surge limit, and/or to accelerate the rotational speed of compressor impeller 123 , and/or to cool the impeller blades 150 , and/or to produce pumping action in the diffuser 190 (if the diffuser is present). Once the compressor 135 has reached its normal operating rotational speed range, the ICE system may be configured in accordance with the turbocharger assembly 101 , wherein a portion of the compressed intake air stream downstream of the compressor 135 is separated, cooled in the vortex tube 120 and injected into the compressor housing 144 where it may be used to favorably shift the surge limit, and/or accelerate the rotational speed of compressor impeller 123 , and/or to cool the impeller blades 150 , and/or to produce pumping action in the diffuser 190 (if the diffuser is present). [0063] The term “intake air” used in this application should be give an broad interpretation so as to include presence of ICE fuel and ICE exhaust gases. Thus, intake air is essentially a mixture of nitrogen, oxygen, carbon dioxide, water vapor, and inert gases, and may also include ICE fuel vapor, nitrogen oxides, and hydrocarbons. In some embodiments of the invention the compressed air for operation of the vortex tube may be derived from the intake air, therefore, the composition of the compressed air may be essentially the same as that of the intake air. [0064] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” and “includes” and/or “including” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. [0065] The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. [0066] Moreover, terms that are expressed as “means-plus function” in the claims should include any structure that can be utilized to carry out the function of that part of the present invention. In addition, the term “configured” as used herein to describe a component, section or part of a device includes hardware and/or software that is constructed and/or programmed to carry out the desired function. [0067] While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the present invention as defined in the appended claims. Furthermore, the foregoing description of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the present invention as defined by the appended claims and their equivalents. Thus, the scope of the present invention is not limited to the disclosed embodiments.

The present invention relates to a turbocharged internal combustion engine (ICE) system having fast response to increased power demand and reduced response time lag. The system includes a vortex tube for delivering cold air into the turbocharger compressor where it may be used to cool the impeller, and/or accelerate the impeller rotational speed, and/or favorably shift the compressor surge line at low speeds and high loads. Cold air from the vortex tube may be also used to operate an ejector pump in the intake duct which further compresses intake air and increases engine charge weight during periods of high power demand. In addition to increasing engine output power, delivery of cold air into engine intake also reduces engine pre-ignition (knocking) thereby reducing emissions. The invention also relates to a method for operating a turbocharged internal combustion engine.

This application is a continuation of application Ser. No. 07/248,388, filed Sept. 23, 1988 now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention concerns a radio controlled timepiece which displays information relating to radio receiving conditions. 2. The Prior Art The timepiece of this type is known from DE 34 39 638 in which the display of the receiving conditions occurs by means of the drive frequency of an indicator hand, or from DE-OS 30 15 312 in which the receiving conditions are displayed as digital quality numbers resulting from the agreement of the pulses received by radio with a standard pulse form. SUMMARY OF THE INVENTION An object of the invention is to provide an autonomous radio controlled timepiece of the aforementioned generic type with appropriate additional uses to attain greater acceptance in the market. This object is attained essentially by equipping a radio controlled timepiece with a display element controlled by a pulse counter which is coupled to a pulse generator. The display element is reset when valid time information is received through radio transmissions. This solution satisfies a subconscious but existing desire of consumers to receive a confirmation of the accuracy of the time display of their autonomous radio controlled timepiece by increasing the amount of information displayed concerning radio transmission receiving conditions. The displayed information conveys how long it has been since the time display of the timepiece has been corrected by means of the legal time radio broadcast and whether it would be appropriate to change the spatial orientation or the location of the radio controlled timepiece in order to obtain better radio receiving conditions. Additionally, the fact that an actual wireless receipt of a coded time information has occurred may be displayed during the reception time, e.g., by a display that varies according to the coding frequency of the instantaneously received time information. If the display of the receiving conditions constantly retains an optimum value, the consumer has the assurance that the periodic monitoring of the time display of his timepiece relative to the legal time transmitted by radio has been performed satisfactorily and that the time display is therefore most probably correct. For example, at each preprogrammed point in time of the monitoring, a numerical count displayed on the display element is to be advanced by one unit, and the count is reset into the initial counting state upon each receipt of valid time information. The lowest value is displayed during the initial counting state and the time information obtained at each predetermined monitoring time ensures that the time display was actually verified (and corrected if necessary). This assurance of the operation and correct time display of the timepiece is of interest when the timepiece is in the form of an alarm clock, such as those known from DE-OS 35 10 636. In this case, the display of receiving conditions is conveniently included in the representation of the prevailing time and the predetermined alarm time, wherein said display may consist of an analog display, but preferably consists of a digital display. In order to be able to convey the date information contained in the radio time information without an excessive display size, an additional display is switched between the alarm time indication and date indication (at least the day and month). It is known from other technologies, such as digital wrist watches, for example, to provide the manual alteration of the display. Separate pushbutton switches are provided appropriately for the advance of the hour display and of the minute display. In the present case these pushbutton switches are used only to change the alarm time displayed and thus do not affect the instantaneous time or date displayed (as these displays are now verified by means of the time information received by radio (and corrected, if necessary)). On the other hand, it is convenient to use these two switches provided for manual display correction, to interrupt or terminate an alarm signal or to switch the additional display (alarm time-date), depending on the position of an operating mode change-over switch. It is particularly convenient for operating reasons to use one of the two existing push button switches to actuate display switching or (depending on the position of the operating mode change-over switch) for a mere interruption of the alarm signal (so-called SNOOZE or repeating signal). In the alarm operation, the final discontinuation of the alarm signal (until the next alarm time setting is attained) takes place only if both existing push button switches are actuated simultaneously, and is confirmed by an acoustic feedback to assure the operator of the alarm status. Additional alternatives and further developments and characteristics and advantages of the invention will become apparent from the dependent claims, with consideration of the abstract, and from the description below of an example embodiment illustrated in the drawing which is restricted to the essential information and described in an abstract manner, of the solution according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 shows an autonomous radio controlled timepiece in the form of a date or alarm clock, with a digital display, FIG. 2 is a simplified, single pole block circuit diagram for obtaining the instantaneous display information concerning receiving conditions, FIG. 3 is a simplified single pole block circuit diagram which operates as a function of an operating mode change-over switch and as a function of two push button switches to affect the time of the alarm and of the alarm signal (without consideration of the additional display switch-over possibilities using the same switches such as between the prevailing date and the predetermined alarm release time), and FIG. 4 illustrates an autonomous radio controlled timepiece according to the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The autonomous radio controlled timepiece 11 consists of a radio receiver 12 and a control circuit 13 to monitor and correct, if necessary, the instantaneous time display in keeping with the instantaneous time information 10 transmitted by a standard time sender, and to provide subsequent internal time keeping operations until the next time information is received, such as described for example in DE 34 39 638 in more detail, which discloses an autonomous radio timepiece as shown in FIG. 4. This radio timepiece includes a radio receiver 101 and a time display device designed to clearly indicate whether the prevailing radio receiving conditions could lead to correction of a potentially incorrect time display without extensive additional efforts relative to the time display. For this purpose, the operation the stepping progress of a hand (for example, the seconds hand 118) is derived from a demodulated pulse sequence 106 containing a decoded time information, and switched to a sequence of internally obtained time keeping pulses 125 if a decoding circuit 107 was able to decode complete time information. Following the activation of the radio timepiece, it is therefore clearly recognizable from the stepping progress of the indicator hand (108 or 118) deviating from the seconds rhythm that inadequate radio receiving conditions are exist. The receiving conditions may be improved (for example by changing the local orientation of the radio timepiece) until the progress of the indicator hand (108, 118) is in seconds. FIG. 4 further shows an autonomous radio timepiece having an internal timekeeping apparatus 126 with an analog time display, a decoding device for decoding coded time information received by radio, and a receiving function indicator, the indicator setting of which is corrected in keeping with the decoded time information. A radio timepiece of this common type is known from the article by H. Effenberger (Institute for Timepiece Technology and Precision Mechanics, Stuttgart University) entitled "Microprocessor controlled radio timepiece with analog display", page 104f of the book Radio timepieces edited by W. Hilberg (R. Oldenbourg Press, 1983), and particularly the display 12 relative to FIG. 1 in combination with the second paragraph of page 107 and page 108, bottom. In this timepiece, specific measures are carried out by a microprocessor program in case of receiving problems and a light emitting diode built into the timepiece is simultaneously actuated emit a blocking signal to be interpreted as an indication of the reception problem. DE-OS 30 15 312 discloses a radio timepiece with a digital display whereby it is possible to carry out an electronic comparison of the receiving pulses containing coded time information with numerically defined standard pulses and to derive therefrom a digital indication relative to the quality of the demodulated receiving pulses, i.e., coded information concerning the instantaneous receiving conditions. Such a digital evaluation of the receiving conditions based on a comparison of pulse forms may be of scientific interest, but for a daily user of a utility timepiece information derived in this manner has no particular significance. A radio timepiece of FIG. 4 is defined as the operative combination of a radio receiver and an autonomously operating timepiece equipped with a time keeping electronic circuit, wherein at certain intervals, the instanteous time display is compared with an actual point in time transmitted by a radio in coded form and corrected in case of deviations. On the other hand, the time piece of FIG. 4 does not concern another common type of timepiece such as disclosed in the article "Radio controlled timepieces" by G. Krug in Timepieces and Jewelry, 8/1971, pages 57-59. The Krug article discloses that a secondary timepiece network is stepped forward from a central source of pulses, whereby the stepping pulses are not transmitted completely by the line network but over longer distance wire-less communications, i.e., by radio. The radio information contains no absolute time information, with the consequence that step displays cannot be changed by means of the radio information from an arbitrary false display setting into a correct setting corresponding to the instantaneous point in time. In the timepiece system described above, designed for trade fair exhibition, with stepping mechanism actuating pulses transmitted by radio, an acoustic indication of the individual decoded stepping pulses is provided, which would be entirely inappropriate for a consumer timepiece in view of the unbearable physiological impact on the environment. Particularly, in the case of a timepiece equipped as a radio timepiece of this common type and which, as a consumer timepiece, may be used in many different locations depending on the instantaneous and changing installation conditions, there may exist a problem relative to the operating technology in that, as a function of the prevailing local conditions and the instantaneous effects of the environment, the reception of the time information in the coded form may be interfered with or even prevented. This has only a small effect to the extent that, as a result the decoding of the instantaneous time information and its comparison with the instantaneous time, display of the timepiece could possibly not take place at the intended point in time and is postponed until there are more favorable receiving conditions present. However, it represents a serious interference if the radio timepiece is located in such an unfavorable place that no valuable reception information may be obtained at all and that therefore, for example upon the actuation of the timepiece, no incorrect display can be corrected to indicate the actual correct point in time. In view of these conditions, it is the object of the timepiece of FIG. 4 to provide a radio timepiece of a common type so that as a conventional analog timepiece it will provide information about whether instantaneous decoding of time information transmitted by radio in a coded form is interfered with or is regular (and therefore leading to a correction of a possibly incorrect indicator setting) in a form readily apparent even to those not skilled in the art. The object of the timepiece shown in FIG. 4 is attained essentially by a radio timepiece including an indicator hand revolving in a stepping mode wherein the actuating signals whereof are obtained from the seconds cycle of the time information received. With this solution no intellectual effort is required for the interpretation of a special electro-optical display, such as for example "synchronization blocked," or for a quantitative comparative evaluation of the quality of demodulated receiving pulse forms. Instead, a hand serving as a time indicator is moved forward by the pulse sequence received and carrying the coded instantaneous time information (appearing regularly in the seconds grid with the suppression of each 59th second of a full minute), i.e., in the conventional rhythmic seconds sequence, in the case of undisturbed receiving conditions at the location of an operational radio timepiece. This indicator stepping movement of the timepiece shown in FIG. 4, which clearly indicates the reception of discrete pulses in the seconds grid involved, may be readily interpreted, if necessary, even by those not skilled in the art, to recognize that the radio timepiece apparently is operating regularly. Such a person will thus understand that the time display, in case of a deviation from the instantaneous time, will be set to the correct time during the next comparison point in time. If, on the other hand, the reception of the coded time information is disturbed, then either certain pulses are missed, or pulses appear in a rapid or irregular sequence relative to seconds cycle. Both of these conditions lead to an unusual movement of the indicator in deviation from the seconds sequence. In any case, it is readily apparent even to those without skills in the art from an irregular indicator movement on the timepiece of FIG. 4, that the instantaneous time display is not secured and that it will not be corrected within a foreseeable period of time. An attempt can then be made to improve receiving conditions by changing the location of the radio timepiece, for example. It is particularly appropriate to carry out this application of the demodulated receiving pulses to the indexing of the indicator hand only at the beginning of the operation and to switch to the internal time keeping circuit as soon as a first complete time information is decoded and made available for time comparison and possibly for display correction. If at this time regular demodulated pulses arriving in the seconds cycle are already present and the seconds hand of a timepiece is chosen as the reception indicator, the user possibly will not even notice the switch of the indexing of the indicator hand (with the exception of the missing 59th pulse) from the demodulated receiving pulses to the (uninterrupted) second cycle of the time keeping circuit; he will therefore not be unnecessarily irritated by it. If, on the other hand, more explicit information of this switching process under undisturbed receiving conditions is desired, it is convenient to choose an indicator hand that normally is not moved in the seconds cycle (i.e., for example the minute or hour hand of the timepiece) which is actuated by its own motor. The switch of the actuation of the hands step motor from the demodulated receiving pulses to the time keeping device may be carried advantageously--especially if the decoding of the time information and the determination and correction of the time display is effected by means of a microprocessor--in a circuitry combination including a decoding circuit and comparison of the time information transmitted in the coded form by radio. The prior art will become more apparent from the description hereafter of the exemplary embodiment shown in a simplified manner in FIG. 4 in the form of a block circuit diagram showing the essential elements. In the radio timepiece of FIG. 4, a radio receiver 101 including a high frequency part 103, an antenna 102 (for example a ferrite rod coil), a demodulator 104 and an output amplifier 105, is supplied with a rectangular pulse sequence 106 having a pulse sequence frequency of 1 Hz which, by means of binary pulse coding, carries complete time and date information (not shown in detail in the FIG. 4) within one minute. If an undisturbed pulse sequence 106 has been received over at least one complete minute, the information relative to the instantaneous point in time may be detected by means of a decoding circuit 107 and compared with the instantaneous time display provided by a hands setting detector 111 in a comparator 110. The time display is in the form of the setting of the hands 108 in front of the minute mechanism on the face 109 of a time piece. The hands setting detector 111 is based for example on rotation angle measurements or incremental step transducers. The pulse sequence passing through a threshold stage 112 (in the example shown with their differentially positive flanks) actuates the dynamic switch inlet 113 of a bistable reversing circuit 114. The switch inlet 113 is actuated at the mutually inverted outlets of the bistable reversing circuit 114 therefore in the rhythm of the pulse sequence 106 alternating H potentials and L potentials. It may be convenient to connect an amplifier 115 after said outlets, which may also be components of a pole reversing bridge circuit. In any case, the signal sequence leading to the succession of rotating steps by one-half of a revolution and consequently by means of a drive clutch 117 to the stepping movement of a hand (here the seconds hand 118) by a one second step, is thus applied alternatingly to a bipolar single-phase control coil of a timepiece step motor placed over the outlets of the bistable circuit 114 and the amplifier 115, if the pulse sequence 106 supplied by the radio receiver 101 is undisturbed, i.e., is present in the seconds grid with a pulse sequence frequency. If, on the other hand, the pulse sequence 106 is disturbed (in the form of missing or interrupted individual pulses), this is immediately apparent from the motion of the indicator hand (here the seconds hand 118), which does not display the usual uniform step movement, but jumps in a unruly manner, for example. A reversing device 119 is preferably provided for the actuation of the step motor 116, by which--as described above--the pulse sequence 106 is conducted from the radio receiver 101 to the reversing circuit 114, whenever the overall apparatus, or at least the receiver 101 is activated following a pause. For example, the activation may be by means of an operating switch 120 or because of the actuation of a power source (for example a battery). In this manner, a setting inlet 123 of the reversing device 119 is actuated, possibly through a trigger circuit 122 to actuate a setting pulse, for the transmission of the pulse sequence 106 to the reversing circuit 114. At the onset of the operation of the timepiece of FIG. 4 therefore the progress of the indicator hand 118 displays the actual passage of time in the seconds grid only if an undisturbed pulse sequence 106 is being received. As soon as the decoding circuit 107 has decoded the time information from said pulse sequence, the reversing device 119 is switched by means of its reset inlet 124 to the reception of the time keeping pulses 125 from a time keeping apparatus 126, i.e., to a timepiece seconds cycle, in which from here on for example a seconds hand 118 is moved (until the next interruption of the operation of the radio timepiece). However, the time keeping pulses may also be temporarily have a higher frequency, if the comparator 110 detects a deviation between the time displayed by the hand 108 and the instantaneous time decoded by the decoding circuit 107. For the sake of clarity, FIG. 4 does not indicate that it may be convenient to provide separately actuated step motors 116 for the seconds hand 118 and the hour and minutes hand 108 and to activate them separately from the comparator 110, in order to make possible the rapid adjustment of the setting of the hour and minutes hand 108, without having to rotate the seconds hand 118 also (at an inappropriate rapid rate by means of an operating clutch). Such separate motors 116 make it possible to further select as the reception indicator hand the minutes or even the hour hand 108; in this case the function of the reversing device 119 would also include the separation of the indicator motor 116 from the receiving pulse sequence 106 and the switching of the time keeping pulse sequence to the timepiece drive circuit. The display of the time information, according to the exemplary embodiment, is not an analog hand display, but a digital indication with a display 14 of grouped digits 15. At least one display element 16, is shown to consist of two digits which, in the exemplary embodiment, serve to display information relative to the prevailing receiving conditions. For this purpose, a counter 17 is connected to a pulse generator 18 (which may consist of the internal time keeping circuit for the autonomous operation of the timepiece) provided in connection with the control circuit 13 for counting pulses. Information proportional to the result of the counting are indicated by means of the display element 16. Whenever the control circuit 13 receives valid instantaneous time information 10 by means of the receiver 12 for comparison with the instantaneous time display 19 (and possibly to correct the instantaneous time display 19), the reset port R of the counter 17 is actuated by the control circuit 13 for resetting the counter to an initial state. The display element 16 indicating the receiving conditions shows an information value in the form of digits which increase with the time elapsed since the last monitoring of the time display. The longer the elapsed time is, the proportionally less assured the agreement between the instantaneous time indication and the prevailing time becomes. Therefore, according to the preferred embodiment, if the initial counting position of the counter 17 is at ZERO value, and a counting pulse is transmitted hourly to the counter 17 and an hourly comparison is made between the prevailing time display 19 with the time information 10 received by radio, the two-digit digital display element 16 is always maintained at "00". If, however, the display increases its hourly count, this signifies that receiving conditions at the location of the radio timepiece 11 are so poor that no received transmissions are decodable, and that no valid time information has been possible to decode over the number of hours indicated and therefore the instantaneous time display 19 is unassured (not verified for an extensive period of time); whereupon the radio timepiece 11 should be placed as soon as possible into a different location or environment in which the built-in antenna of the radio timepiece is capable of undisturbed radio reception to thereby receive valuable time information 10. Additionally, the display element 16 may provide a signal when the radio timepiece is switched to receive the prevailing time information for the control of the instantaneous time display 19. This may be effected for example by means of a modulator circuit 21, actuated by the receiver 12 in the seconds frequency of the time information coding, thereby leading to the flashing in seconds of at least one of the digits 15 of the display element 16. If the display 14 comprises, in addition to the time display 19, a supplemental display 22, the display element 16 associated with the receiving conditions is appropriately located in the center of the display 14 between two displays 19 and 22 and thus have a subdued order of magnitude relative to the other conspicuous elements, as shown in FIG. 1. The supplemental display 22 may represent date information also transmitted by radio and, during autonomous operation, may be derived from the flow of time. The date information may be displayed, for example, by two pairs of numerical digits 15, each followed by a period 23. Instead or alternatively, the supplemental display 22 may also consist of an alarm indicator, comprising the two numerical digit pairs 23 preceded by letter digits 15 "AL" (FIG. 1). Thus, if the radio timepiece 11 is equipped as a timer or alarm clock, the AL display 22 indicates the manually set point in time at which an alarm signal will be emitted. While the setting of the time display 19 and the supplemental date display 22 is carried out automatically upon the receipt of radio transmitted time information 10 by means of the control circuit 13, the setting of the time of the alarm requires a manual operation. For this, an operation mode changeover switch S3 is brought into the SET position, whereupon the digit pair indicating the hours or minutes is changed stepwise by means of the push button switches S1 and S2, for example, advanced in accordance with the manual switch actuation. If the operation mode changeover switch is not in the SET position, the actuation of one of the push button switches S1 and S2 switches the supplemental display 22 between the alarm time set (FIG. 1) and the date. In this process, the instantaneous display 22 may be maintained until the next push button actuation, or automatically returned to a preferred display 22 by means of circuitry. In the ON setting of the operation mode changeover switch S3 a coincidence stage 25 is activated, which in case of the coincidence of the preset alarm time with the prevailing time, actuates, by means of a coincidence signal 26, a bistable stage 27 of an alarm emitter 28 (for example a piezoelectric transducer) for the emission of an alarm signal 24. If either one, but only one of the push buttons S1 or S2 is actuated, the trigger circuit 27 is reset by means of an exclusive-OR-gate 29 and a monostable trigger circuit 30 is started in order to reset the bistable stage 27 to induce emission of an alarm signal after a certain predetermined pause (SNOOZE-alarm repetition function). If both push button switches S1 and S2 are actuated simultaneously (i.e., with time overlap), the response is not by the exclusive-OR-gate 29, but by an AND gate 31 connected to the switches S1 and S2, whereby the signal emission stage 27 is reset to discontinue the alarm signal. If, at that instant no alarm signal 24 was being emitted, at least a very brief confirmation signal emission is triggered by means of a trigger circuit 32 (optionally unique in frequency or modulation), which represents an acoustic acknowledgment of the overlapping actuation of the two push button switches S1 and S2. This "AL STOP" actuation further insures that an alarm signal is again emitted only when a coincidence is again attained in the time display between the instantaneous setting display 22 and the actual time display 19 (e.g., 24 hours). A timer circuit 33 started when the alarm transducer stage 27 is in the set position, serves to automatically terminate the emission of the alarm signal 24 after a certain period of time provided no manual interruption or termination is executed by means of the push buttons S1 and S2, in order to prevent a continuing disturbance or an unnecessary load on a source of energy (e.g., a battery) of the radio timepiece 11. In the OFF position of the operation mode changeover switch S3, the bistable alarm transducer stage 27 is conveniently rigidly locked in the reset position, so that no alarm release could occur by means of the coincidence stage 25. The gate circuit shown in FIG. 3 further insures that only in the SET position of the operation mode changeover switch S3 could one (and instantaneously only one) of the push buttons S1 and S2 be actuated to modify the alarm time setting to the coincidence stage 25; while in the two other positions of S3 (ON or OFF) a signal 34 is generated, which permits the information display of the supplemental display 22 to switch (date-alarm timing) upon the actuation of one of the push buttons S1, S2. For the sake of clarity, this is not shown in the circuitry in FIG. 3. In the example of the embodiment depicted in the drawings, the gate circuit and the effects of the monostable and bistable trigger stages are conveniently not illustrated by a discrete circuit layout, but are depicted as supplemental functions of a central processor, which is contained in the control circuit 13. The control circuit 13 provides the periodic actuation of the receiver 12, the decoding of the absolute time information 10 received by radio and, if necessary, the correction of the time and date displays 19, 22. It will be appreciated by those of ordinary skill in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics 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 that came within the meaning and range of equivalents thereof are intended to be embraced therein.

An autonomous radio controlled timepiece having a display for displaying information relative to receiving conditions to provide the consumer with increased assurance regarding the accuracy of the instantaneous time display. For this purpose, an analog or digital, optionally multidigit display element is provided, which displays supplemental information concerning the quality of reception, expressed as an indication of the period of time elapsed since the most recent monitoring and possible correction of the time display, the correction based on the information received by radio and decoded. The display element offers the lowest possible display value if the radio reception conditions are good enough that each actuation of the receiver leads to the acquisition of usable time information. The degree of certainty in the accuracy of the time display predisposes the timepiece to be used as an alarm clock in particular, in which case the alarm clock need only be equipped with setting elements for preselecting the time of alarm, for an alarm interruption or deactivation, and optionally for the switching of a supplemental display between displaying the preselected time of alarm and date information obtained from the radio information.

FIELD OF THE INVENTION This invention relates to blood oxygenators and more particularly to an oxygenator using a waterless heat exchanger separate and detachable from the oxygenation portion of the oxygenator. BACKGROUND OF THE INVENTION Blood oxygenators are well known and are routinely used to temporarily assume the function of the lungs in certain surgical procedures such as open heart surgery. Although the principal function of the oxygenator is to store blood and conduct an oxygen-carbon dioxide gas exchange with the patient's blood, it also traditionally serves the function of regulating the blood temperature as various phases of the surgery require. In a conventional oxygenator, blood temperature is regulated by causing the blood to flow through a heat exchanger in which a heat exchange takes place through metal or plastic interfaces between the blood and a temperature-controlled stream of water. The heat exchanger is conventionally incorporated into the oxygenator so that the blood follows a continuous path in the oxygenator, first through the heat exchanger and then through the gas exchanger. Whenever blood and water are present in the same device, there is an inherent danger that one may accidentally leak into the other and interfere with the patient's well-being. Also, the water connection lines to the oxygenator, which is usually mounted on the heart-lung machine, can become snagged and lead to accidents. Equipment is further required for controlling the water temperature. Placing the temperature control equipment directly into the oxygenator would solve the water problem, but this is impractical because the required equipment would be too bulky to fit into a reasonably sized oxygenator, and because the equipment would be too expensive for incorporation in a disposable device, which the oxygenator must be. SUMMARY OF THE INVENTION The present invention solves the above-described problems of the prior art by providing, in an oxygenator, a heat exchanger in which a thin film of blood passes along an interface which intimately engages a corresponding interface on a permanent heater-cooler housing onto which the oxygenator is mounted for use. Various embodiments of the invention described herein deal with the geometry of the interfaces for uniform control of the blood temperature, i.e., a geometry such that no part of the blood path is more than about one or two millimeters from the interface. Examples of such a geometry are large, flat surfaces lying against each other; convoluted surfaces that plug into each other; or spiral vanes defining a uniformly thin blood path between them. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the components of the inventive apparatus; FIG. 2 is a detail sectional view illustrating one embodiment of the invention; FIG. 3 is a detail sectional view illustrating another embodiment of the invention; and FIG. 4 is a detail sectional view illustrating a third embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of the invention, and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. FIG. 1. shows the basic components of the apparatus 10 of this invention as mounted on a heart-lung machine 11: a blood oxygenator 12, a blood heat exchanger 14, and a heater/cooler 16. The heat exchanger 14 and the blood oxygenator 12 may be formed together in a single housing, or they may be separate and connected only operatively by tubing 18. The heater/cooler 16 may advantageously be a heat pump, or it may contain separate heating and cooling devices; in either event, it is preferably an electrical device of a conventional nature whose function is to maintain the interface 20 at a selectable temperature. The interface 20 consists of two parts; the heat transfer face 22 which is part of the heater/cooler 16, and the heat transfer face 24 which is part of the blood heat exchanger 14. In all of the embodiments of the invention, it is important that the faces 22, 24 be in close physical contact with each other when the inventive apparatus is assembled. Preferably, the faces 22, 24 are made of metal, but either of them could also be made of other suitable materials that exhibit a high heat conductivity. Because it is important that the blood flowing through the heat exchanger 14 be heated or cooled as uniformly as possible, it is desirable that no part of the blood path past the face 24 be more than a maximum distance d (preferably about 1-2 mm) away from the face 24. A corollary of this is that the area of the face 24 should be as large as possible, and that the blood flow past face 24 should be as slow as possible. The various embodiments shown in FIGS. 2-4 illustrate various ways in which this can be done. In FIG. 2, the heat pump or other heating/cooling device 30 of the heater/cooler 16 controls the temperature of a large, flat, preferably metallic plate 32 which constitutes face 22. The face 24 of the heat exchange 14 would in this case also be a flat plate 34 which lies in physical contact with the face 22 when the heat exchanger 14 is mounted on the heater/cooler 16 by an appropriate means such as a bracket 36. If the heat exchanger 14 is integrally formed with the oxygenator 12, the blood path 38 through the heat exchanger 14 would be the large, planar space, about 1-2 mm thick, between the plate 34 and the wall 40 of the oxygenator 12. FIG. 3 illustrates a way of obtaining a larger interface area in a smaller area, by forming the plates 32 and 34 with intermeshing convolutions 42. The convolutions 42 may be so formed as to allow the heater/cooler 16 and the heat exchanger 14 to engage each other in the way an electric plug engages a wall outlet. FIG. 4 shows an embodiment in which the heat exchanger 14 is arranged in the central core of the oxygenator 12. In that embodiment, the plate 32 takes the form of a generally cylindrical finger that extends into the oxygenator 12 and therein contacts the plate 34. In the embodiment of FIG. 4, the plate 34 is shaped to form a recess or socket 44 in the center of a generally cylindrical blood heat exchange chamber 46 extending through the central core of oxygenator 12. In order to maintain a blood path in which no part of the path is more than the distance d from a heat exchange plate, the plate 34 is provided with metallic spiral fins 48 which extend from the plate 34 to the wall of the chamber 46. The fins 48 cause the blood to travel spirally around the plate 34 in a thin sheet while being continuously exposed to heat or cold which the fins 48 draw from the plate 34. It is understood that the exemplary blood oxygenator with the waterless heat exchanger described herein and shown in the drawings represents only a presently preferred embodiment of the invention. Indeed, various modifications and additions may be made to such embodiments without departing from the spirit and scope of the invention. Thus, other modifications and additions may be obvious to those skilled in the art and may be implemented to adapt the present invention for use in a variety of different applications.

Waterless temperature control of blood in a blood oxygenator is achieved by providing a non-disposable heater/cooler with a temperature-controlled surface that can be intimately mated with a heat-conducting surface of a disposable blood heat exchanger associated with the oxygenator. Blood flows in a shallow path past the heat-conducting surface so that substantially all of the blood will assume the temperature of the heat-conducting surface as it flows past that surface.

BACKGROUND OF THE INVENTION This invention relates to a tensioner which maintains a belt or chain of an internal combustion engine in a suitable tension state. In the tensioner, a tension rod energized by a spring force abuts againsts a belt, chain or the like directly or indirectly through a pulley thereby providing a fixed stress to the belt or the chain by the urged force thereof. For this purpose, in a fundamental construction of the tensioner, a tension rod is provided in a casing so as to be able to advance and a spring for advancing the tension rod is provided in the casing. However, since such tensioner is energized by a spring, this has such dangers as an unexpected advancement of the tension rod and the projecting form the casing before assembling of a device or at the time of removing it from the device. For this purpose, the tensioner is provided with a stopper mechanism which locks the advancement of the tension rod. In the traditional stopper mechanism a hole having a small diameter is formed in both the tensioner and the casing, and the advancement of the tension rod is locked by inserting the stopper pin into each pin hole of the tensioner and the casing during insertion of the stopper pin. After assembling the tensioner to the device, the urging operation of the tension rod due to the spring force is performed by drawing out the stopper pin. However, in the traditional stopper mechanism when the stopper pin is drawn out, it is necessary to align the casing and the tension rod for inserting the stopper pin through the pin hole of the tension rod. However, this positioning is very difficult. Further, the locking portion with the stopper pin is only one portion with respect to the advancing direction of the tension rod and locking of the tension rod of an arbitrary position is impossible. By this, since the removal of the tensioner for maintenance is performed in a state wherein the advancing force is loaded on the tension rod, the whole tensioner is twisted to gnaw at a bolt as the bolt is slackened which increases the difficulty of the removing of the tension rod. This invention is an improvement over the above cases, and provides a tensioner in which it is possible to lock the tension rod at an arbitrary position with a simple operation, easily and securely. BRIEF SUMMARY OF THE INVENTION In order to achieve the above the object, this invention is provided with a friction force. In other words, this invention is characterized in that in a tensioner wherein the tension rod advances from the casing by energizing a compression spring to maintain a belt or a chain in a suitable tension state, a coil portion is outwardly inserted through the tension rod in a closely contact state and a friction brake, wherein one end thereof being latched with the casing and another end thereof being an operation end which performs enlarging and shrinking of a diameter of the coil portion, is provided with the friction brake thereby preventing the advancement of the tension rod and the removal thereof. The friction brake locks the advancement of the tension rod by a friction force in a closely contacting state of the brake to the tension rod. When the operation end is operated so that diameter of the coil portion is enlarged, the friction force is removed, the tension rod is in an unlocked state. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, FIG. 2 and FIG. 3 represent a first example of this invention and are a sectional view, a side view and an elevation view taken on line I--I in FIG. 2 respectively, FIG. 4 and FIG. 5 are a side sectional view and a side view of a second example repectively. FIG. 6, FIG. 7 and FIG. 8 represent a third example and are a sectional view, a side view and a rear elevation taken on line VI--VI in FIG. 7, respectively. DETAILED DESCRIPTION OF THE INVENTION Now, some examples according to this invention will be described hereinafter with reference to the accompanying drawings. In explaining the drawings, the same element is shown with the same number. FIG. 1, FIG. 2 and FIG. 3 represent the first example of this invention. The tensioner 1 is provided with a cylindrical casing 3, a tension rod 2 inserted into the casing 3 so as to be able to advance and retreat, a compression spring 4 secured between the casing 3 and a tension rod 2 and a friction brake 5 which locks the advancement of the tension rod 2. In the casing a securing piece 6 for fixing the tensioner 1 to a suitable fixing member is formed so that it may project to both sides thereof, the securing piece 6a being provided with a securing hole 6 wherein a bolt penetrates therethrough. The top end side (left side) of the casing 3 is opened and the tension rod 2 is inserted from the open end side. In the tension rod 2, a bored hole 8 opened to the bottom side of the casing 3 is formed in an axial direction. A guide 9 is inserted suitably between tension rod 2 and casing 3 so that the advancement and the retreatment of the tension rod 2 may be performed stably. Further, a flange piece 2a extending outwards is formed at the base side of the tension rod 2 and when the flange piece 2a abuts the guide 9, the advancement of the tension rod 2 is stopped. In other words, the distance between the flange piece 2a and the guide 9 forms an effective stroke length of the tension rod 2. This guide 9 is fixed by a stopper pin 7 pentrating into the guide 9 and the casing 3 so that it may not move by the friction force between tension rod 2 and guide 9 due to the advancement of the tension rod 2. The compression spring 4 is inserted into the penetrated hole 8 of such tension rod 2, one end thereof abutting against the back surface of the top end portion of the tension rod 2 and another end abutting against the bottom portion of the casing 3 thereby providing an advancing force in an axial direction to the tension rod 2. By providing such compression spring 4 positioned in an axial direction of the tension rod 2, the tension of the belt or the chain can be maintained within a suitable range, because it energizes the advancement of the tension rod 2 and enables a compression response to a reaction force when the reaction force is due to an excess tension to the tension rod 2. The friction brake 5 is composed of a locking spring 10 for locking consisting of a coil spring outwardly inserted through the tension rod 2 and a bearing 11 secured adjacent to the locking spring 10. The friction force of the locking spring 10 is caused by an inner diameter of the coil of said locking spring 10 being wound to be somewhat smaller in diameter than the outer diameter of the tension rod so that the locking spring 10 may impart a friction force to the tension rod 2. In this example, the twisted spring 10 is formed by a wire rod having a rectangular sectional area thereby increasing a contact area with tension rod 2. One end portion 10b of the coil portion is bent in the axial direction and inserted to latch into a latching hole of the bearing 11, another end portion 10a being bent in a diameter direction of the casing 3. End portion 10a of this locking spring 10 is drawn out from the casing 3 outwardly, and at the drawing out end portion thereof a knob 12 being provided. In FIG. 2, the numeral 13 is a slit formed in the casing 3 so that end portion 10a of the locking spring 10 may be drawn out. When the knob 12 is allowed to slide in the locking direction along the slit 13, to the lock position the coil diameter of the locking spring 10 shrinks whereby the advancement of the tension rod 2 is locked against by energized force of the locking spring 10 for exerting the friction force to the tension rod 2. On the contrary, when the knob 12 is allowed to slide in an opening to the open position, the coil diameter of the locking spring 10 is enlarged whereby the locking is removed and the tension rod 2 is energized to advance by the spring force of the compression spring 4. The opening side in the slit 13 is bent to be "C" type. When the knob 12 is moved to the end portion thereof, the automatic return of the knob 12 is prevented. By this, an enlarged state of the diameter of the locking spring 10 is maintained and the tension rod 2 is energized to advance by the coil spring 4 whereby the operation of the tensioner 1 moves to a successive state. On the other hand, the bearing 11 is positioned at the opening side of the casing 3 with respect to locking spring 10, and the end surface of the locking spring 10 forming a taper surface 11a having a fixed inclined angle. Further, the "lock" side end portion of the slit 13 bent in the advancing direction of the tension rod to form a guide slit 30 which opens to the top end surface of the casing 1. The end portion 10a of the locking spring 10 is guided by this guide slit 30 to attach within the casing 1. On the other hand, the bearing 11 is positioned to the opening side of the casing with respect to the locking spring 10 and the end surface of the locking spring 10 side forms a taper surface 11a. The bearing 11 is secured to the opening of the casing 3 to seal the open end side of the casing 3 and the tension rod 2 is inserted therein whereby the bearing 11 serves as a guide for the movement of the tension rod. In FIG. 1, the numeral 14 is a fixed pin for securing the bearing 11 to the casing 3. The locking spring 10 side of such bearing 11 forms a tapered surface and the coil portion of the locking spring 10 moves along the tapered surface by energizing the tension rod 2 in a locking state in an advancing direction with the compression spring 4 whereby a clamping force to the tension rod 2 due to a reduce diameter of the coil portion operates so as to increase safety. In such an example, since the clamping to the tension rod 2 by the friction brake 5 is always performed by the operation of knob 12, the locking of the advancement of the tension rod 2 can be performed at an arbitrary position at any intermediate position. Accordingly, the detaching of the tensioner can be performed in a state having no load of compression spring 4 by locking the tension rod 2 in an advanced state at the detaching time of the tensioner for maintenance and the like and an excess advancement of the tension rod 2 can be prevented, in safety. FIG. 4 and FIG. 5 represent the second example of this invention. The same element as the first example is shown by the same reference numeral. In this example, a shaft 20 extending in the axial direction is located at the central portion of the tension rod 2 and this shaft 20 is drawn out toward the outside from the base side of the casing 3. At the drawing out end portion of the shaft 20, is secured a stopper 21 which stops the coming out of the tension rod 2 from the casing 3. On the other hand, the casing 3 is separated by the bearing 11 to the first separating chamber 22 wherein the compression spring 4 and the tension rod 2 are contained therein and the second separating chamber 23 where the friction brake 5 is contained therein. The top end of the first separating chamber is open, and in the open end portion thereof is fixed a bearing plate 24 to be a guide for the tension rod 2. A circlip 25, located at the inner portion of the casing 3, guides the moving of the tension rod by holding the tension rod between the bearing plate 24 and the bearing 11. On the other hand, within the second separating chamber 23 is provided locking spring 10 and tapered surface 11a at the side of the bearing 11 of the locking spring 10. In this case, the locking spring 10 is outwardly inserted into a shaft 20 of the tension rod 2, one end 10b thereof being inserted into the bearing 11 to be latched with it, whereby the advancement of the tension rod is adapted to be locked at any intermediate position by the friction force thereof. In such second example, since the friction brake 5 acts on shaft 20 of the tension rod 2, a coil spring having a small diameter can be used as a locking spring 10, whereby the locking operation can be implemented easily by positioning the locking mechanism at the opposite side against the advancing side of the tension rod 2. FIG. 6, FIG. 7 and FIG. 8 illustrate a third example of this invention. In this example, the casing 3 is provided integrally at the side of the supporting block 26, the interior of the casing 3 being provided with tension rod 2, guide 9 and friction brake 5 consisting of locking spring 10, and bearing 11 having the taper surface 11a at the side of the locking spring 10. Further, the compression spring 4 is provided at the penetrated hole 8 of the tension rod 2, said compression spring 4 consisting of an outer spring 27 having a large diameter and an inner spring 28 having a small diameter, said springs 27 and 28 biasing the tension rod 2. Furthermore, the outer spring 27 and inner spring 28 in this example are made of wires. The spring made by such an element thereby being able to decrease a resonance energy of the belt or chain. As described above, since the friction brake which locks the advancement of the tension rod by the friction brake 5 which locks the advancement of the tension rod by the friction force of the spring, is provided in this invention. The tension rod can be locked at an arbitrary position thereby increasing ease of maintenance and safety.

In a tensioner, a friction brake locks the advancement of a tension rod by a friction force provided and a tension rod advances from a casing by the pressurizing of the compression spring to maintain a belt, chain or the like in a suitable tension state. A coil portion is outwardly inserted through the tension rod in a closely contacted state and one end of the coil portion is latched to the casing, while another end forms a friction brake which is an operation end to cause an enlargement or the shrinkage of the diameter of the coil portion, by which the advancement and the removal of the tension rod is performed.

BACKGROUND OF THE INVENTION This invention relates to the use of a C3-C5 hydrocarbon such as propane as a chain transfer agent in the preparation of fluoropolymers, especially to the free radical polymerization of vinylidene fluoride monomer optionally conducted in the presence of other fluorinated olefins. Various efforts have been tried over the years to find a suitable chain transfer agent for such polymerizations, as disclosed in the background section of U.S. patent application Publication 2002/0147289 A1. For example, the emulsion polymerization at moderate pressure of vinylidene fluoride using fluorinated surfactant and, as a free-radical initiator. diisopropyl peroxydicarbonate (hereinafter referred to as IPP) is taught in U.S. Pat. No. 3,475,396. The same patent teaches that the amount of fluorinated surfactant necessary in the system can be reduced if a chain transfer agent is present in the reaction system. U.S. Pat. No. 4,569,978 discloses the use of trichlorofluoromethane (CFC-11) as a chain transfer agent to reduce or eliminate the discoloration and cavity formation phenomenon but this CFC is an ozone depleting material and its use is being, banned worldwide. U.S. Pat. No. 3,635,926 discloses an aqueous process for making tetralluoroethylene/fluorovinyl ether (TFE/FVE) copolymers in the presence of chain transfer agents such as hydrogen and methane in combination with CFCs and HCFCs. In this patent only perfiltoromonomers (mainly TFE) were considered and methane was the most preferred chain transfer agent since it exhibited a reasonable chain transfer activity in the polymerization of perfluoromonomers; however, high alkanes were reported to be too active to be used in polymerization due to undesired (slowing) effect on the polymerization rate. The aforesaid Application 2002/0147289 discloses the use of ethane as a chain transfer agent in a free radical polymerization of vinylidene fluoride. However, higher alkanes, including propane, were reported to be too active to be used due to an undesired slowing effect on the polymerization rate. In contrast to above disclosures regarding fluorinated monomers, it has surprisingly been found that the use of C3-C5 hydrocarbons such as propane as a chain transfer agent in the vinylidene fluoride polymerization process results, particularly in the case of vinylidene fluoride homopolymers, in a product with good color which resists discoloration at elevated temperatures. In fact, propane has been found to be about ten times as efficient as CFC-11 and about three times as efficient as ethane. Indeed, among all hydrocarbons, propane surprisingly provides the highest polymerization rate per initiator consumption at a given degree of polymerization. Propane is also inexpensive and non-hazardous. SUMMARY OF THE INVENTION In a process for the free radical polymerization of vinylidene fluoride monomer, optionally in the presence of other fluorinated olefins, this invention provides the improvement comprising the use of a C3-C5 hydrocarbon such as pentane, butane or, preferably, propane as the chain transfer agent. The amount of hydrocarbon can vary widely, but, in the case of propane, less is required than with previous agents such as ethane. The hydrocarbon can be added in batch or continuous feed, depending on the desired molecular weight distribution. The polymerization media normally comprises water or carbon dioxide (such as supercritical and/or liquid carbon dioxide). The preferred free radical initiators are di-n-propyl peroxydicarbonate or di-isopropyl peroxydicarbonate. In another preferred process aspect, vinylidene fluoride homopolymer is produced. DETAILED DESCRIPTION The manner of practicing the invention will now be generally described with respect to a specific embodiment thereof, namely polyvinylidene fluoride based polymer prepared in aqueous emulsion polymerization using propane as the chain transfer agent. The polymers are conveniently made by an emulsion polymerization process, but suspension and solution processes may also be used. In an emulsion polymerization process, a stirred reactor is charged with deionized water and fluorinated surfactant and this initial charge is deoxygenated while agitated. The reactor temperature is raised to the desired polymerization temperature, the predetermined amount of propane is introduced, and either vinylidene fluoride alone or a mixture of monomers such as vinylidene fluoride and hexafluoropropylene are fed to the reactor. The temperature of the reaction can vary depending on the characteristics of the initiator used, but is typically from about 30° to 130° C., preferably from about 50° to 110° C. Once the pressure in the reactor has reached the desired level, an initiator emulsion, made of a dispersion of either di-isopropyl peroxydicarbonate or di-n-propyl peroxydicarbonate in water, is charged to start the polymerization reaction. The polymerization pressure may vary, but typically will be within the range of about 20 to 50 atmospheres. Following the initiation of the reaction, the vinylidene fluoride or vinylidene/hexafluoropropylene mixture is continuously fed along with additional initiator to maintain the desired pressure. Once the desired amount of polymer has been reached in the reactor, the monomer feed(s) will be stopped, but initiator feed is continued to consume residual monomer(s). In order to avoid compositional drifts in case of copolymers, after reactor pressure drops to a given level, a shot of vinylidene fluoride is added to bring the vinylidene fluoride concentration up. This step may be repeated more than one time depending on the hexafluoropropylene concentration in the reactor. When the reactor pressure is low enough, about 300 psig, the initiator charge is stopped and after a delay time the reactor is cooled. The unreacted monomer(s) and propane are vented and the latex is recovered from the reactor. The polymer may then be isolated from the latex by standard methods, such as acid coagulation, freeze thaw or shear coagulation. Although the process of the invention has been generally illustrated with respect to the polymerization of vinylidene fluoride homopolymer, one of skill in the art will recognize that analogous polymerization techniques can be applied to the preparation of copolymers of vinylidene fluoride with coreactive monomers fluorinated or unfluorinated such as hexafluoropropylene and the like. Analogous techniques can also be applied using propane as a chain transfer agent in the polymerization of other fluorinated polymers, both homopolymers and copolymers. Surfactants suitable for use in the polymerization are well known in the art and are typically water soluble halogenated surfactants, especially fluorinated surfactants such as the ammonium, substituted quaternary ammonium or alkali metal salts of perfluorinated or partially fluorinated alkyl carboxylates, the perfluorinated or partially fluorinated monoalkyl phosphate esters, perfluorinated or partially fluorinated alkyl ether or polyether carboxylates, the perfluorinated or partially fluorinated alkyl sulfonates, and the perfluorinated or partially fluorinated alkyl sulfates. Some specific, but not limiting examples are the salts of the acids described in the U.S. Pat. No. 2,559,752 of the formula X (CF 2 ) n COOM, wherein X is hydrogen or fluorine, M is an alkali metal, ammonium, substituted ammonium (e.g., alkylamine of 1 to 4 carbon atoms), or quaternary ammonium ion, and n is an integer from 6 to 20; sulfuric acid esters of polyfluoroalkanols of the formula X (CF 2 ) n CH 2 OSO 3 M, where X and M are as above; and salts of the acids of the formula CF 3 (CF 2 ) n (CX 2 ) m SO 3 M, where X and M are as above; n is an integer from 3 to 7, and m is an integer from 0 to 2, such as in potassium perfluoroctyl sulfonate. The use of a microemulsion of perfluorinated polyether carboxylate in combination with neutral perfluoropolyether in vinylidene fluoride polymerization can be found in EP0816397A1 and EP722882. The surfactant charge is from 0.05% to 2% by weight on the total monomer weight used, and most preferably the surfactant charge is from 0.1% to 0.2% by weight. Paraffin antifoulant is an optional additive, and any long-chain, saturated, hydrocarbon wax or oil may be used for this purpose. Reactor loadings of the paraffin typically are from 0.01% to 0.3% by weight on the total monomer weight used. The propane may be added all at once at the beginning of the reaction, or it may be added in portions, or continuously throughout the course of the reaction. The amount of propane added as a chain transfer agent and its mode of addition depends on the desired molecular weight characteristics, but is normally used in an amount of from about 0.5% to about 5% based on total monomer weight used, preferably from about 0.5% to about 2%. It has been found that substitution of methane for propane shows no reduction in molecular weight (MW), that is, that it has no chain transfer effect in polyvinylidene fluoride polymerizations. When ethane is used, the polymerization rate was significantly slower than that of propane, as a result of which the initiator consumption was higher which in turn will have a negative impact on product color. While butane and pentane give satisfactory results, propane surprisingly results in the fastest polymerization rates. The reaction can be started and maintained by the addition of any suitable initiator known for the polymerization of fluorinated monomers including inorganic peroxides, “redox” combinations of oxidizing and reducing agents, and organic peroxides. Examples of typical inorganic peroxides are the ammonium or alkali metal salts of persulfates, which have useful activity in the 65° C. to 105° C. temperature range. “Redox” systems can operate at even lower temperatures and examples include combinations of oxidants such as hydrogen peroxide, t-butyl hydroperoxide, cumene hydroperoxide, or persulfate, and reductants such as reduced metal salts, iron (11) salts being a particular example, optionally combined with activators such as sodium formaldehyde sulfoxylate, metabisulfite, or ascorbic acid. Among the organic peroxides which can be used for the polymerization are the classes of dialkyl peroxides, diacylperoxides, peroxyesters, and peroxydicarbonates. Exemplary of dialkyl peroxides is di-tbutyl peroxide, of peroxyesters are t-butyl peroxypivalate and t-amyl peroxypivalate, and of peroxydicarbonate, and di(n-propyl) peroxydicarbonate, diisopropyl peroxydicarbonate, di(sec-butyl) peroxydicarbonate, and di(2-ethylhexyl) peroxydicarbonate. The use of diisopropyl peroxydicarbonate for vinylidene fluoride polymerization and copolymerization with other fluorinated monomers is taught in U.S. Pat. No. 3,475,396 and its use in making vinylidene fluoride/hexafluoropropylene copolymers is further illustrated in U.S. Pat. No. 4,360,652. The use of di(n-propyl) peroxydicarbonate in vinylidene fluoride polymerizations is described in the Published Unexamined Application (Kokai) JP 58065711. The quantity of an initiator required for a polymerization is related to its activity and the temperature used for the polymerization. The total amount of initiator used is generally between 0.05% to 2.5% by weight on the total monomer weight used. Typically, sufficient initiator is added at the beginning to start the reaction and then additional initiator may be optionally added to maintain the polymerization at a convenient rate. The initiator may be added in pure form, in solution, in suspension, or in emulsion, depending upon the initiator chosen. As a particular example, peroxydicarbonates are conveniently added in the form of an aqueous emulsion. The term “vinylidene fluoride polymer” used herein for brevity includes both normally solid, high molecular weight homopolyiners and copolymers within its meaning. Such copolyiners include those containing at least 50 mole percent of vinylidene fluoride copolymerized with at least one comonomer selected from the group consisting of tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, hexafluoropropene, vinyl fluoride, pentafluoropropene, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether and any other monomer that would readily copolymerize with vinylidene fluoride. Particularly preferred are copolymers composed of from at least about 70 and up to 99 mole percent vinylidene fluoride, and correspondingly from 1 to 30 percent tetrafluoroethylene, such as disclosed in British Patent No. 827,308; and about 70 to 99 percent vinylidene fluoride and 1 to 30 percent hexafluoropropene (see for example U.S. Pat. No. 3,178,399); and about 70 to 99 mole percent vinylidene fluoride and 1 to 30 mole percent trifluoroethylene. Terpolymers of vinylidene fluoride, hexafluoropropene and tetrafluoroethylene such as described in U.S. Pat. No. 2,968,649 and terpolymers of vinylidene fluoride, trifluoroethylene and tetrafluoroethylene are also representatives of the class of vinylidene fluoride copolymers which can be prepared by the process embodied herein.

Vinylidene fluoride polymers are produced by using a C3-C5 hydrocarbon as a chain transfer agent in the free radical polymerization process.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Not Applicable STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX [0003] Not Applicable BACKGROUND OF INVENTION [0004] The use of ceiling panels, particularly but not exclusively for decoration, is well known. Ceiling panels are typically composed of sheet metal with an embossed decorative pattern or of non-metallic material, such as asbestos or cellulose-like materials. The non-metallic ceiling panels have many deficiencies. Consequently metal ceiling panels, particularly those fabricated of tin, are preferred. However, the installation of metal ceiling panels presents challenges. [0005] Most non-suspended ceilings are constructed of sheetrock. Traditionally metal ceiling panels have been installed, that is, affixed to the ceiling, by using nails at the corners or at the perimeter of each individual ceiling panel. However, due to the nature of the composition of sheetrock, nails cannot adequately affix metal ceiling panels to sheetrock due to the inability of nails to adequately grip and hold firmly to the sheetrock and the resultant tendency of the nails to slip-out of overhead sheetrock over a period of time, thereby releasing the panels from the ceiling, which of course is most undesirable. [0006] Consequently, the traditional approach to installing metal ceiling panels to sheetrock ceilings is to first install a plywood surface over the entire sheetrock ceiling, and to then subsequently nail each of the metal ceiling panels into the thusly installed plywood. This is a labor intensive, time consuming and costly installation procedure. [0007] An alternative but equally undesirable approach is to install wooden strips on the sheetrock ceiling, and to then nail each of the metal ceiling panels into the wood strips. With this approach, it is essential for the wood strips to be aligned very carefully to assure that the strips do in fact align with the edges of the panels as they are installed. Although easier than covering an entire sheetrock ceiling with plywood prior to installation of metal ceiling panels, this wooden strip approach is also still a very a labor intensive, time consuming and costly installation procedure. [0008] In addition, metal ceiling panels traditionally have been installed by being placed side-by-side with each other, without any interlocking mechanism to attach adjoining ceiling panels to each other during the installation process, or indeed otherwise. Such interlocking of contiguous ceiling panels would both facilitate the installation process and would also enhance the structural integrity of the installed metal ceiling panel matrix grid. [0009] The manual dexterity necessary to install ceiling panels overhead is tremendous; not only does the installer need to assure proper alignment of each panel, but that installer must simultaneously also hold and support the panel in an overhead position while handling nails and a hammer. [0010] An objective of the present invention is to solve the aforesaid problems. BRIEF SUMMARY OF THE INVENTION [0011] A preferred embodiment of the invention is the interlocking capability and characteristics of two or more ceiling panels to be installed contiguously with each other, particularly when installed onto a sheetrock ceiling surface as depicted in FIGS. 1 through 6 hereof. [0012] This invention addresses and solves the traditional challenges and problems encountered prior to this invention with the installation of metal ceiling panels by avoiding the costly and time consuming installation of plywood or wooden strips between the sheetrock ceiling and the metal ceiling panels to be attached to that sheetrock ceiling. [0013] This invention further addresses and solves the traditional challenges and problems encountered prior to this invention by the installer having had to simultaneously hold the ceiling panel in place overhead during the installation process, also assuring proper positioning and alignment of each panel, while also handling the affixing nails and operating the hammer by which the nails were driven through the ceiling panel and into the underlying plywood or wood strips. [0014] The present invention solves the foregoing problems. The resultant ability for a ceiling panel to be held in position during installation other than by being continually held in place by the hands of the installer while the installer is simultaneously juggling nails and hammer, coupled with the ability to install metal ceiling panels directly to a sheetrock ceiling without the otherwise need for plywood or wood strips, results in the installation of metal ceiling panels being appreciably less labor intensive, less time consuming and consequently less expensive than otherwise. BRIEF DESCRIPTION OF THE DRAWINGS [0015] The illustration of a preferred embodiment of the invention is shown on the accompanying drawings in which: [0016] FIG. 1 is a view of the finished, embossed front face of a representation of a typical ceiling panel. [0017] FIG. 2 is an isometric view of a ceiling panel, looking upward toward a ceiling on which the said ceiling panel is to be installed, simultaneously showing bottom and side perspectives. [0018] FIG. 3 is a depiction of a matrix grid of multiple ceiling panels installed on a ceiling. [0019] FIG. 4 is a cross-section of the male interlock component feature of the invention, not inserted into the female interlock component feature of the invention. [0020] FIG. 5 is a cross-section of female interlock component feature of the invention, without the male interlock component feature of the invention inserted therein. [0021] FIG. 6 is a cross-section of the male interlock component feature of the invention inserted into the female interlock component feature of the invention, showing a series of installed contiguous ceiling panels. DETAILED DESCRIPTION OF THE INVENTION [0022] One preferred embodiment of the invention is depicted as a metal ceiling panel in FIGS. 1 through 6 hereof, which provides the ability for the installation of a ceiling panel directly into a sheetrock ceiling without the otherwise need for first installing a plywood surface or wood strips to the sheetrock ceiling. [0023] This is accomplished through the combination of an interlocking mechanism within each ceiling panel by virtue of which immediately adjoining ceiling panels are reversibly and removably connected to each other prior to being affixed to the sheetrock ceiling in conjunction with other ceiling panels then being affixed to the sheetrock ceiling by screws inserted through holes in the flanges of the ceiling panels. [0024] FIG. 1 is a view of the finished front face of a ceiling panel ( 101 ), in which there are four side edges shown as ( 103 ), ( 105 ), ( 107 ), and ( 109 ). [0025] FIG. 2 is an isometric view of the ceiling panel depicted in FIG. 1 , but with the side edges which had been depicted in FIG. 1 as ( 103 ), ( 105 ), ( 107 ), and ( 109 ) now depicted for emphasis in a magnified, out-of-proportion depiction as ( 203 ), ( 205 ), ( 207 ), and ( 209 ). [0026] FIG. 3 is a depiction of a matrix grid ( 310 ) comprised of twelve of the ceiling panels ( 101 ) depicted in FIG. 1 . The use of twelve ceiling panels in this matrix grid is only for purposes of illustration, with the matrix grid actually being any number of ceiling panels configured in an interconnected matrix grid of such ceiling panels. [0027] FIG. 4 depicts a cross-section of the male interlock component feature of the invention ( 401 ), in which there are both convex protrusions ( 403 ) and ( 405 ), and also resultant concave indentations ( 407 ) and ( 409 ) from the plane of the male interlock component feature of the invention ( 401 ). [0028] The use of two such protrusions and two such indentations is only for purposes of illustration, with the actual number of such protrusions and indentations being one or more, but certainly not limited to two. [0029] The surfaces of protrusions ( 403 ) and ( 405 ) can be either smooth or alternatively can be coated, treated or otherwise conditioned or textured to thereby increase the coefficient of friction between said surfaces ( 403 ) and ( 405 ) with the surfaces of any materials with which they are placed in contact, including the surface of the interior wall ( 511 ) of the female interlock component feature of the invention. [0030] Similarly, the surfaces of indentations ( 407 ) and ( 409 ) can be either smooth or alternatively can be coated, treated or otherwise conditioned or textured to thereby increase the coefficient of friction between said surfaces ( 407 ) and ( 409 ) with the surfaces of any materials with which they are placed in contact, including the surfaces of protrusions ( 507 ) and ( 509 ) on the surface of the interior walls ( 511 ) of the female interlock component feature of the invention. [0031] FIG. 5 depicts a cross-section of the female interlock component feature of the invention ( 501 ), in which there are both convex protrusions ( 507 ) and ( 509 ), and also resultant concave indentations ( 503 ) and ( 505 ) from the plane of the female interlock component feature of the invention ( 501 ). [0032] FIG. 5 also depicts a relatively flat surface ( 511 ) facing and directly opposite to surfaces of protrusions ( 507 ) and ( 509 ). [0033] In addition, FIG. 5 depicts a hole ( 513 ) through which a screw or other affixing means may be inserted to affix the ceiling panel, of which the female interlock component feature of the invention ( 501 ) is a part, onto a sheetrock ceiling. [0034] The use of two such protrusions and two such indentations is only for purposes of illustration, with the actual number of such protrusions and indentations being one or more, but certainly not limited to two. [0035] The surfaces of protrusions ( 507 ) and ( 509 ) can be either smooth or alternatively can be coated, treated or otherwise conditioned or textured to thereby increase the coefficient of friction between said surfaces ( 507 ) and ( 509 ) with the surfaces of any materials with which they are placed in contact, including the surfaces of indentations ( 407 ) and ( 405 ). [0036] FIG. 6 depicts a cross-section of portions of two ceiling panels ( 601 ) and ( 605 ), each of which is connected to the depicts the entire ceiling panel ( 603 ). [0037] Each ceiling panel in that preferred embodiment depicted in the FIGS. 1 through 6 hereof has two male side edges ( 207 ) and ( 209 ) and two female side edges ( 203 ) and ( 205 ). One or more holes ( 211 ) exist in each flange portion of the said male side edges ( 203 ) and ( 205 ) to allow for the insertion of a screw or other affixing means by which the ceiling panel is affixed to a sheetrock ceiling. [0038] In the installation process, the said male side edges ( 207 ) and ( 209 ) are inserted into the female side edges ( 203 ) and ( 205 ), respectively. The said ceiling panels, when thusly connected with each other, interlock in a “snap-lock” fashion, thereby self-aligning themselves with other ceiling panels previously installed in the matrix grid ( 301 ) and providing a means for the ceiling panels subsequently installed to be similarly self-aligned. [0039] In addition, once so connected and interlocked the said ceiling panels are relatively self-supporting, and need no longer be held in the hands of the installer. Consequently, the installer then has both of his hands free to use for holding nails, screws, hammers, screw drivers or any other tools used to affix the ceiling panel matrix grid to the sheetrock ceiling. [0040] As the male interlock component feature of the invention as depicted in FIG. 4 is inserted into the female interlock component of the invention as depicted in FIG. 5 , (as shown fully inserted in FIG. 6 ), surfaces ( 407 ) and ( 403 ) are initially placed in contact with surfaces ( 509 ) and ( 511 ), respectively, and as the insertion continues, those surfaces ( 407 ) and ( 403 ) are then and finally placed in contact with surfaces ( 507 ) and ( 511 ), respectively, while simultaneously surfaces ( 409 ) and ( 405 ) are then and finally placed in contact with surfaces ( 509 ) and ( 511 ), respectively. [0041] During and in the course of the aforedescribed insertion procedure, the said protrusions and indentations [( 403 ), ( 405 ), ( 407 ), ( 409 )] of the said male interlock component feature of the invention ( 401 ) and the said protrusions an indentations [( 503 ), ( 505 ), ( 507 ) and ( 509 )] of the said female interlock component feature of the invention ( 501 ) are temporarily plastically flexibly displaced or deformed, or both, to thereby allow for the said insertion, after which insertion the said protrusions and indentations return to their original shapes and forms. [0042] Upon completion of the said insertion procedure, there is a resulting secure interlock between the two adjacent ceiling panels thus connected. Notwithstanding the said interlock, the said connected ceiling panels are still forcibly separable by applying sufficient force to one ceiling panel in a direction which is opposite to that simultaneously applied to the other then connected second ceiling panel. [0043] Each ceiling panel ( 101 ) in the matrix grid ( 301 ) is affixed to the ceiling by means of screws ( 607 ) inserted through screw holes ( 513 ) [also shown as ( 211 ) in FIG. 2 ]. [0044] It is contemplated that the inventive concepts herein described may be variously otherwise embodied and it is intended that the appended claims be construed to include alternative embodiments of the invention except only insofar as limited by prior art.

A panel, for installation on a ceiling as a component of a matrix grid of similar panels, with the ceiling panels capable of being installed directly on sheetrock ceilings without the otherwise need for affixing a wooden structure to the sheetrock ceiling before affixing the ceiling panels.

This application is: a divisional application of U.S. patent application Ser. No. 492,420 filed Mar. 6, 1990, now U.S. Pat. No. 5,097,232; which is a continuation of U.S. patent application Ser. No. 368,992 filed Jun. 16, 1989, now abandoned; which is a continuation of U.S. patent application Ser. No. 253,411 filed Oct. 10, 1988, now abandoned; which is a continuation of U.S. patent application Ser. No. 009,275 filed Jan. 1, 1987, now abandoned. BACKGROUND OF THE INVENTION The present invention relates generally to signal transmission lines built on silicon wafers for the purpose of wafer-scale integration, and more particularly to micro-strip signal transmission lines for programmable interconnection wafers which are constructed to optimize signal transmission speeds. In the past, integrated circuit (IC) chips were electrically connected together through the use of "pin" packages and printed circuit boards. Each IC chip would first be mounted in the cavity of a separate pin package which had to be large enough to provide a number of sturdy pin connections. Then, these IC chips containing packages would be mounted to a printed circuit board which was designed to provide a specific pattern of electrically conductive paths necessary to interconnect the pins of these packages together in the desired way. While this technique of interconnecting IC chips together has been used for many years, it has several drawbacks. In the first place, it takes up far too much room. Since the IC chips themselves occupy only a very small amount of a typical pin package, and the pin packages must be separated on the circuit board, a great deal of wasted space is built in to each multi-chip circuit design. While the amount of this wasted space can be reduced by integrating more transistors into each IC chip, eventually the designer will be faced with the need to interconnect various IC chips together in order to achieve a unique circuit design. Accordingly, achieving higher densities within each chip only addresses one aspect of the wasted space problem. The interconnection between discrete IC chips must still be addressed in order to provide a truly dense circuit design. It will also be appreciated that substantial costs are associated with this type of low density interconnection technique. Each circuit board has to be individually designed to provide a printed pattern of conductive paths which is appropriate to the size, type and number of IC chips contained on the circuit board card. Additionally, a separate pin package must be provided for each IC chip manufactured, and these pin packages may also have to be designed specifically for its intended IC chip. Perhaps the most important consideration involved in interconnecting IC chips together is one of time. Since the conductive paths through the pin packages and the circuit board are relatively long, the operation of the IC chips is constrained by the time it takes for signals to be transmitted between the IC chips. Accordingly, if the length of these conductive paths can be reduced, then the transmission delays can also be reduced as well. This consideration is particularly important in the field of super computers where processing speed and heat dissipation are paramount considerations. In order to decrease the distance between IC chips, "thick film" ceramic circuit boards have been proposed. While such circuit boards permit the mounting of IC chips directly to the ceramic substrate of these boards, the layout of conductive paths for these circuit boards still need to be individually designed for each application. Additionally, the density of the number of IC chips per circuit board area is limited by the nature of the pattern of conductive paths which is typically formed on a single layer of the ceramic substrate. A further advance toward the goal of providing dense interconnections between IC chips has recently been realized through the use of a universally programmable silicon circuit board (SCB). An SCB is a standardized, electrically programmable interconnect system which is formed on a silicon wafer or substrate. An SCB can be characterized as "thin film" circuit board technology, due to the fact that the conductive paths have dimensions in the micron region. The SCB permits a product designer to mount diverse IC chips and hybrid components directly to a very compact silicon substrate which acts as a circuit board. No pin packages are required, and the SCB can be programmed electronically so that a single SCB design can serve a wide variety of multi-chip circuit designs. Each SCB includes a matrix of orthogonal metal lines which are disposed on distinct planes. These planes are separated at crossovers by an amorphous silicon material which normally has a high resistance. However, this layer of amorphous silicon is designed to operate as an "anti-fuse" in that selected electrical connections can be made between the metal lines on different planes. Specifically, when a threshold voltage is applied to the amorphous silicon, the material will switch from a high resistance value to a low resistance value at a desired interconnection point. This "anti-fuse" capability of the amorphous silicon allows many thousands of possible interconnections to be made between various metal lines of the SCB matrix, and hence a host of different IC chip interconnections can be readily made using automated programming techniques. In addition to the above, other advantageous features of the SCB include the ability to mount the IC chips to the substrate through conventional wire bonding techniques, and temperature matching of silicon IC chips with the silicon substrate to reduce stress and fatigue. The integrity of the interconnection network can also be automatically tested, and faults can be readily corrected by programming alternate routes through the network. The electrical programming of the network by firing the appropriate "anti-fuses" can be accomplished within hours, so that a design engineer does not have to wait long periods of time for masks to be developed and the like. A further general discussion of SCBs may be found in the following references: U.S. Pat. No. 4,467,400, issued on Aug. 21, 1984 to Herbert Stopper, entitled "Wafer Scale Integrated Circuit"; U.S. Pat. No. 4,479,088, issued on Oct. 23, 1984 to Herbert Stopper, entitled "Wafer Including Test Lead Connected To Ground For Testing Networks Thereon"; U.S. Pat. No. 4,458,297, issued on Jul. 3, 1984 to Herbert Stopper et. al., entitled "Universal Interconnection Substrate"; and an article entitled "A Wafer With Electrically Programmable Interconnections", 1985 IEEE International Solid-State Circuits Conference, Digest of Technical Papers, pp. 268-269. These references are hereby incorporated by reference. As will be discussed further below, the metal lines of the SCB may approach the "lossy line" transmission characteristics of a Thomson Cable. This lossy line characteristic has the advantage of eliminating the need for terminating resistors. However, this characteristic can also result in undesirable transmission delays through the interconnection network. Specifically, for homogeneous metal lines in an SCB network, this delay has been found to be proportional to the square of the length. Accordingly, it should be appreciated that the length of the SCB signal transmission lines can become an important design consideration when extremely high processing speeds are desired. Thus, one one hand, long signal transmission lines can facilitate the interconnection of many IC chips on a single SCB. However, on the other hand, it is possible that such long signal transmission lines may not be consistent with achieving the goal of maximizing the overall processing speed for multi-chip circuits and other micro-electronic circuits. Accordingly, it is a principal objective of the present invention to provide an interconnection method and apparatus for increasing signal transmission speeds through micro-electronic circuits. It is a more specific objective of the present invention to provide an improved SCB transmission line network geometry which approaches an almost linear relationship between the length of the transmission line and the signal delay through the transmission line. It is another objective of the present invention to provide an interconnection method and apparatus which maximizes the signal transmission speed over a given distance, such that over this distance the transmission line is capable of modeling the signal transmission characteristics of a coaxial "lossless" transmission line. It is a further objective of the present invention to provide a method and apparatus for increasing signal transmission times which achieves an optimum relationship between total resistance of the transmission line and its characteristic impedance. It is an additional objective of the present invention to provide a plurality of micro-strip transmission line structures which can be readily fabricated and interconnected together in combination to achieve a high speed signal transmission path. It is yet another objective of the present invention to provide a high speed transmission path for use in a variety of micro-electronic circuit applications, including applications with signal frequencies above 1 GH z . It is still another objective of the present invention to create a high speed transmission path which provides an optimized termination resistor effect that is distributed along the transmission path. SUMMARY OF THE INVENTION To achieve the foregoing objectives of the present invention, a method of optimizing the signal transmission between a signal source and a signal receiver is disclosed which includes the steps of providing a signal transmission path or transmission line structure which is "semi-lossy", nonhomogeneous and governed by a predetermined relationship between its length and its various electrical parameters. A transmission line in this context is primarily an R-L-C line composed of two conductors having a loop resistance R, a loop inductance L, and a conductor to conductor capacitance C. For the convenience of further discussion, a loss factor can be defined as ##EQU1## Strictly speaking, a lossy line is one with α>0, and a lossless line is one with α=0. Practically and customarily, however, a line for micro-electronic assemblies is considered to be lossless for α<<1 and lossy for α>>1. Lossless lines are known to impose a delay on a signal traveling from the signal source to the signal receiver which can be calculated as t o =√LC. This delay varies linearly with the length of the line and is equal to the delay which would be incurred by a light wave travelling through the same medium. Hence, this delay is the smallest delay which can be attained by any means. Lossy lines, on the other hand, are known to impose a delay which can be approximately calculated as t.sub.α =√LC (1+α). This delay varies approximately with the square of the line length and can be significantly larger than the minimum delay t o . Lossless lines are known to require terminators, i.e., resistors whose value is equal or close to the characteristic impedance ##EQU2## of the line. Terminators can be placed at either or both ends of a line. Without terminators, multiple signal reflections at both line ends would lead to intolerable signal distortions otherwise known as over-shooting, under-shooting, ringing, or bouncing. Lossy lines, on the other hand, are known to be free of such problems even when used without any terminators. A transmission line according to the present invention is optimized for a fixed length in such a way that it shares with the loss-less line the property of minimal, linear delay and with the lossy line the property of zero bouncing without terminators. Thus, under the appropriate circumstances, a signal can travel through a micro-electronic assembly on a signal path designed according to the methods of the present invention at essentially the speed of light and without bouncing. The possibility of using thin film lossy lines for propagating high speed pulses near the speed of light without terminating resistors has been discussed in the following references: U.S. Pat. No. 4,210,885, issued on Jul. 1, 1980 to Chung W. Ho, entitled "Thin Film Lossy Line For Preventing Reflections In Microcircuit Chip Package Interconnections"; and an article entitled "The Thin-Film Module As A High-Performance Semiconductor Package," by C. W. Ho, et. al., IBM J. Res. Develop., Vol 26, No. 3, May 1982, pgs. 286-296. However, as will be appreciated from the description below, the present invention provides several advantages not found in these references. For example, the present invention provides a way of increasing the transmission line length while still permitting propagation speeds approaching the speed of light. Additionally, a critical transmission line distance has been found in which the signal being received will precisely reproduce the waveform of the signal transmitted at the other end of the transmission line. A transmission line optimized according to the methods of the present invention has a loss factor in the vicinity of 1 and could therefore be called "semi-lossy." It is important to understand that in most micro-electronic assemblies and particularly in SCB's the physical constraints are such that lossy lines can be made easily but lossless lines cannot be made at all. The lossy lines, however, can be upgraded to be semi-lossy lines by appropriate design. It is therefore a particular accomplishment of the present invention to provide a transmission line which can be produced even under the physical constraints of an SCB and which is still superior to either of the previously known lines, namely, the lossless and the lossy line. The previous discussion implied that the lines considered, be they lossy, lossless, or semi-lossy according to the present invention, are homogeneous, i.e., that the electrical parameters R,L,C if normalized per unit of length do not change over the length of the line. Nonhomogeneous lines, on the other hand, are lines in which these parameters do change, either abruptly at certain points or continuously along the line. The methods of the present invention make use of nonhomogeneity in order to either increase the fixed length for which optimization can be performed or to ease the physical construction of micro-electronic transmission lines at lesser distances. Particularly in SCB's, nonhomogeneous lines are applied in such a way, that they simultaneously serve the purposes of implementing programmable routing and enhancing signal transmission characteristics. For example, in a transmission line network where optimization cannot be achieved, the use of nonhomogeneous lines according to the present invention can still provide improvements in transmission speeds. In one form of the present invention, a nonhomogeneous signal transmission path is constructed from a plurality of different micro-strip conductors which are connected together for transmitting a signal in a particular direction. Preferably, three sets of micro-strip conductors of varying width are formed in two separate planes of a substrate structure which will enable interconnections to be made between these conductors. The two planes have distinctly different altitudes over a common ground plane which is used as a common current return path for all conductors in the structure. Specifically, the widest conductor is placed into the upper plane and connected to the signal source, the narrowest conductor is also placed into the upper plane but connected to the signal receiver, and the conductor of intermediate width is placed into the lower plane and used to interconnect the other two conductors together. It should be appreciated that the principals of the present invention are susceptible for use in a variety of micro-electronic circuits and other applications involving transmission lines whose characteristics can be optimized in accordance with the present invention. Thus, for example, the present invention can be used in a wide range of interconnection technologies, even within the IC chips themselves. Additional advantages and features of the present invention will become apparent from reading of the detailed description of the preferred embodiments which make reference to the following set of drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a SCB structure whose general layout is applicable to the method and apparatus according to the present invention. FIG. 2 is an artist's conception, in perspective, of a general SCB layout for purposes of illustration. FIGS. 3A-3C are schematic circuit diagrams of electrically long, single phase, transversal electromagnetic transmission lines which are lossless (A), piecewise approximated lossy (B), or semi-lossy (C). FIGS. 4A-4B are diagrammatic representations of nonhomogeneous transmission line structures according to the present invention. FIG. 5 is a graph illustrating relative time delays for homogeneous and non-homogeneous lossy lines versus a homogeneous lossless line. FIG. 6 is a diagrammatic representation of a nonhomogeneous micro-strip conductor structure formed in two planes according to one embodiment of the present invention. FIG. 7 is a drawing of a micro-strip line example of transmission line according to a method of the present invention for controlling the relationship between the total resistance of the line and its characteristic impedance. FIG. 8 is an enlarged top elevation view of a portion of the SCB shown in FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a plan view of an SCB 10 is shown. While the general layout of the SCB 10 is applicable to the method and apparatus according to the present invention, it should be appreciated that the principles of the present invention are not limited to this particular SCB structure or any SCB structure. As will be appreciated from the description below, the present invention is applicable to a wide variety of micro-electronic circuit interconnection technologies. Accordingly, while the present invention is particularly applicable for use in SCB structures, the SCB structures described below are set forth for exemplary purposes only. The SCB 10 is fabricated using a thin silicon wafer as a substrate or base for the composite SCB structure. The SCB 10 provides a pair of generally square sections or segments 12 and 14 for mounting a plurality of IC chips to the SCB substrate. For example, FIG. 1 shows IC chips 16 and 18 which are wire bonded to the segment 12 of the SCB 10. Similarly, FIG. 1 also shows a set of five IC chips 20-28 which are wire bonded to the section 14 of the SCB 10. As will be discussed below in connection with FIG. 2, the SCB 10 provides a matrix of micro-strip conductors whose interconnections are programmed to provide a network of signal transmission paths between the appropriate IC chips mounted to the SCB substrate. The combination of the SCB 10 with the IC chips (such as chips 16-18 and 20-28) provide a hybrid circuit and wafer assembly which can be used in virtually any electronic circuit application. The silicon wafers of the segments 12 and 14 are mounted to a header assembly 30. The header assembly 30 provides several input and output lines 32 which extend to the periphery of the SCB 10. Accordingly, the periphery of the SCB 10 provides a connector junction for interfacing the SCB to other circuits and devices. Referring to FIG. 2, an artist's conception of an SCB section or cell 34 is shown in a way which illustrates the matrix of micro-strip conductors used in the SCB structure. It should be understood that this Figure is not intended to depict an acutal SCB structural design. Rather, FIG. 2 is being used to illustrate the basic elements used in an SCB structure. As shown in FIG. 2, the SCB section 34 includes a first set of micro-strip conductors 36 which are aligned in parallel along one horizontal plane of the SCB. The micro-strip conductors 36 are generally referred to as "pad" lines, as each of these lines is provided with at least one bonding pad 38. The bonding pads 38 are used to connect IC chips, such as the IC chip 40, to the network of micro-strip conductors provided in the SCB. In this regard, conventional wire bonding techniques can be used to connect an appropriate lead of the IC chip with the pad of an appropriate micro-strip line conductor 36. The SCB section 34 also includes a second set of micro-strip conductors 42 which are aligned in parallel along a horizontal plane which is beneath the plane used for the pad lines 36. The micro-strip conductors 42 are generally referred to as "net" lines, as they provide the necessary links to create a signal transmission path network through the SCB. Since the net lines 42 may be used to transmit a signal to a plurality of receivers, these lines may generally be wider than the pad lines 36. This difference in width between pad lines and net lines is illustrated in FIG. 7 of U.S. Pat. No. 4,458,297, which has previously been incorporated by reference. It should also be noted that more than one plane of pad lines 36 and/or net lines 42 may be provided in an appropriate SCB structure. The pad lines 36 are separated from the net lines 42 at their cross-over points by a continuous layer of an amorphous silicon material (SiO 2 ), which is more fully described in the Ronald G. Neale U.S. Pat. No. 3,675,090, issued on Jul. 4, 1982, entitled "Film Deposited Semiconductor Devices," which is hereby incorporated by reference. One unique characteristic of this amorphous silicon material is that it has the ability to act as an electronic switch or "anti-fuse." More specifically, the amorphous silicon material is capable of switching from a normal insulating state (e.g., >200 MΩ) to an electrically conductive state (e.g., <5Ω). This switching is achieved by electrically "firing" individual cross-over points or bridges between selected pad and net lines. Specifically, a threshold voltage (e.g., approximately 20 volts) is applied across the amorphous silicon bridge which will cause the amorphous silicon to switch to a stable conductive state. Accordingly, it should be appreciated that this switching ability enables selected pad lines 36 to be interconnected to selected net lines 42 through an electrical programming process to create a desired network of signal transmission paths through the SCB. In this regard, the amorphous silicon material has been referred to as an "anti-fuse," because it is normally an insulator, whereas a fuse is normally a conductor. However, it should be understood that other suitable semiconductor materials may be used in the place of the amorphous silicon material, as long as they have the ability to switch between conductive and nonconductive states. Thus, for example, certain amorphous chalcogenide materials have been suggested for the purpose. FIG. 2 also illustrates that the SCB section 34 includes a pair of conductor planes 44 and 46. These conductor planes are used to provide electrical power connections for the SCB structure. The conductor plane 44 is preferably used as the ground plane, while the conductor plane 46 is preferably used as the voltage plane. However, it should be appreciated that the role of these two conductor planes could be reversed in the appropriate application. Each of the conductor planes 44 and 46 are preferably made out of aluminum, as are the micro-strip conductors 36 and 38. However, other suitable electrically conductive materials may be used in the appropriate application. Each of the conductor planes 44 and 46 are provided with a plurality of pads for enabling the appropriate power connections to be made with each of the IC chips wire bonded to the SCB structure. For example, FIG. 2 illustrates a pad 48 which is connected to the conductor plane 44 through a pedestal 50. Similarly, FIG. 2 illustrates a pad 52 which is connected to the conductor plane 46 through a pedestal 54. The conductor plane 46 is preferably formed on a thin silicon wafer which extends across the entire matrix of micro-strip conductors used in the SCB. In general, it is a goal of the present invention to increase the signal transmission speed in otherwise lossy transmission paths, such as a Thomson Cable transmission line, while avoiding the requirement of a termination resistor. Such an increase in the signal transmission speed is particularly advantageous in an SCB interconnection network, since the delay has been found to be proportional to the square of the length of the micro-strip conductors. Thus, for example, if it is assumed that a particular lossy transmission line has a delay T for one-third of the total length of the line, then the transmission delay over the entire length of the line would be nine times T. However, in accordance with the present invention, the design parameters of the signal transmission paths in an SCB interconnection network can be optimized so as to substantially reduce the transmission delay times. Additionally, the signal transmission paths according to the present invention can be used to carry signals of extremely high frequencies (e.g., greater than 1 GH z ). It will, of course, be appreciated that in most SCB applications, interconnections will not always be made at the extreme ends of the lines, and that a line may also have two or more orthogonally directed lines connected across its length. Accordingly, these line loading effects will make it difficult to accurately determine the propagation delays through an interconnected network without actual testing or speed simulations. Nevertheless, the present invention provides two complementary techniques for substantially reducing the transmission delays which achieve surprising results. For example, it will be shown that there is a critical line length which will enable the waveform of the transmitted signal to be precisely reproduced at the receiver on the first transition. FIGS. 3A-3C show schematic diagrams of three transmission line circuits 56-60. FIG. 3A is drawn around a length of coaxial cable 62 which is a classical example of a single-phase, transverse electromagnetic (TEM) transmission line. The coax cable 62 serves only as an example and the transmission characteristics explained below are equally applicable to any other conductor pair which can sustain TEM waves, particularly a micro-strip over a ground plane. The coax cable 62 is presumed to have an inductance L and a capacitance C, but no resistance. A signal put on line by the signal generator or source 64 arrives at the signal receiver 66 after a time delay t o =√LC. The signal may see an amplitude modification A at the receiver end which is governed by the value of the terminating resistor R T as follows: ##EQU3## Ideally, R T is equal to Z o which leads to A=1. For larger or smaller values of R T , the line shows ringing. In the extreme cases of R T =0 or R T =∞, the signal bounces back and forth between the endpoints of the line forever. FIG. 3B shows a piece-wise approximation of a line with not only distributed inductance and capacitance but also with distributed resistance. At the end of each cable section 68, a partial signal reflection will take place and the resulting amplitude (the sum of the arriving and the returning signal) will be modified by a factor which follows the same rule which is valid for the end of the line in FIG. 3A, except that R T has to be replaced by the load represented by the following line section. This load, including the series resistor R/n, is equal to R/n+Z o , except for the last section where the load "resistor" is infinite. At the same time, there will be a voltage reduction at each input of a line section 68 because the series resistor R/n and the line input resistance Z o comprise a voltage divider. Thus, the original signal supplied by the signal generator is increased or decreased at each junction as it travels down the line and has experienced a total amplitude modification when it arrives at the signal receiver which can be expressed by the factor ##EQU4## With the introduction of a loss factor ##EQU5## this equation can be rewritten as ##EQU6## The initial waveform travelling down the line creates reflections at the end of each line section 68 which in turn create more secondary reflections. However if "n" is a large number, the numerous but individually small reflections add up in such a way that their sum is slowly moving smooth curve which provides the transition from the initial response delineated by the above factor A to the final response. It is important to note that the time required by the initial waveform to reach the signal receiver is equal to that found in the lossless line of FIG. 3A because the sum of the lengths of the "n" sections is equal to the length of the whole line, hence again ##EQU7## FIG. 3C shows an R.L.C. line 70 with a truly distributed resistance. Its amplitude transfer function can be derived from the previous case by growing "n" to infinity: ##EQU8## Again, a replica of the original signal from the signal generator 64 with a scaling factor A is presented to the signal receiver 66 after the minimum delay time of t o =√LC. After the arrival of the replica, additional slow responses follow which become negligible as A approaches 1. In other words, when A=1, the waveform of the transmitted signal signal will be reproduced at the receiving end of the line without any adverse reflections being generated. For example, with a step signal being transmitted down the line, this step function will be reproduced at the receiving end with a sharp rise and little or no tail. An optimized line can thus be defined as a line which is characterized by A=1 which, in the case of the most simple implementation with only one homogeneous line, is synonymous with α=1n2 or R=2 (1n2) Z o =1.39Z o . This means that the optimized, semi-lossy, unterminated line 70 duplicates the behavior of the terminated, lossless line. This optimization is related to a fixed distance in as much as R is a function of distance or line length while R T is not. It should be appreciated that a fixed line length in the context of an SCB is not a restriction but a design parameter. Another way of describing the optimized line is to say that the discrete terminator R T =R o has been replaced by a distributed terminator R=1.39Z o . The concept of the optimized line can be illuminated further by the following design example. FIG. 7 shows a micro-strip line 72 with a width w, a thickness s, a height h over the ground plane 74, and a length d. The resistance of line 72 can be calculated as ##EQU9## and the characteristic impedance Z(o) can be calculated as ##EQU10## δ is the resistivity of the conductor material. ε r is the permittivity of the dielectric between the conductors. K is the fringe field correction factor which can be approximated as ##EQU11## and which usually ranges between 0.5 and 0.9. If δ=3×10 -8 μm (aluminum), ε r =4 (silicon dioxide), and K is assumed to be 0.7 for simplicity, then the dimensions of the micro-strip may be optimized as follows: ##EQU12## If the desirable length d of the lines on an SCB is 40 mm, the design requirements are reduced to h·s=6.54 (μm) 2 . An example of a design which would satisfy this equation would be s=2 μm, h=3.27 μm. It should be noted that this optimization is not overly sensitive to variations from the ideal condition of R=1.39Z o . Depending on pulse rise times, this ideal condition can be missed by a factor on the order of 1.5 without substantial performance degradation. However, variations from the ideal condition will cause the amplitude modification factor A to change from A=1, such that a precise replica of the signal waveform will not be achieved. FIGS. 4A and 4B show two examples of non-homogeneous transmission line circuits 76-78. The transmission line of FIG. 4A is comprised of two series connected or cascaded sub-lines 80-82 which are homogeneous in themselves. Similarly, the transmission line of FIG. 4B is comprised of three sub-lines 84-88 which are homogeneous in themselves. While these two transmission line structures are preferred embodiments of the present invention, it should be understood that the principals of using nonhomogeneous lines is not restricted to any particular number of sub-lines or even any identifiable sub-lines which are homogeneous in themselves. The sub-lines 80-82 in FIG. 4A by themselves behave like a homogeneous transmission line except that the reflection-related voltage increase at the end of the first line is ##EQU13## instead of 2. Therefore, the total amplitude transfer factor is ##EQU14## It can now be seen, that optimization (A=1) can be reached for atenuation values which are larger than in the case of the homogeneous line, provided that Z o2 >z o1 . In one preferred embodiment of an SCB according to the present invention, the impedance relation is Z o2 =2Z o1 , the loss factor relation is α 1 =α 2 =α/2 and, hence, ##EQU15## From this optimization equation follows α=0.98. Thus, α has been improved over the homogeneous case by a factor of 0.98/0.69=1.42. An improved (increased) α means that the length of the line can be increased for the same cross section or that the cross section can be made easier to manufacture for the same line length. Since optimization according to the present invention is based on the manipulation of the first pulse or signal transition arriving at the end of the line, it is necessary that the two sub-lines are equally long. If they are not, the optimized loss factor will be somewhere between 0.98 and 0.69, and the improvement will be accordingly smaller. The line of FIG. 4B, is analyzed similarly, yields ##EQU16## Again, improvements, can be gained if Z 03 >Z 02 >Z 01 . In one embodiment of an SCB, parameters are chosen such that Z o3 =2Z o2 =3Z o1 , α 1 =α 2 =α 3 =α/3, and hence ##EQU17## Optimization (A=1), in this case, leads to α=1.16. While FIGS. 4A and 4B illustrate non-homogeneous transmission lines having two and three sub-lines or sections respectively, the following equations may be used to generally characterize the amplitude transfer factor for a non-homogeneous transmission line. If it is assumed that Z o of the first subsection is called Z a and that both R/n and Z o for the following subsections are increased from subsection to subsection by a factor F (which implies that the attenuation factor per subsection remains constant), then: ##EQU18## Accordingly, the equation for A n now becomes: ##EQU19## The relations become clearer if one substitutes ##EQU20## and obtains ##EQU21## The difference between the non-homogeneous and the homogeneous line is then that the attenuation factor α is reduced by an amount β. If Z 0 of the last subsection is called Z B , the equation for 1/F can be transformed into ##EQU22## This means that the characteristic impedance grows exponentially over the length of the line from Z A to Z B with a growth factor ##EQU23## The critical distance can now be redetermined such that A=1, and a "stretch factor" s c can be obtained by dividing the new critical distance over the old one: ##EQU24## With Z B /Z A =4, for instance, s c =2. This means that ideal transmission conditions are now found for lines with the length 2d c rather than d c . In practice, it may be desirable to grow Z o not exponentially but rather in one or two discrete steps, which will reduce the stretch factor slightly. Thus, for example, with two steps and Z B /Z A =4, then S c =1.83. Since β subtracts from but does not divide into α, the stretch factor decreases with increasing line length but not as drastically and as far as suggested by the equation for "A" set forth above, because of the not yet considered secondary component. In this regard, the summated effect of all the reflections and re-reflections on the line output signal is referred to as the secondary component. In contrast, what reaches the end of the line first may be called the primary component of the output signal. FIG. 5 shows stretch factors obtained by simulation and their effect on t e as a function of d o . In this regard, t e is the end of line delay, d o is the total distance, and d c is the critical distance. The overall result is that lossy lines can be made quite effective up to at least 3d c by suitable impedance control. In order to provide proper distributed termination for very short lines, the above process can be reversed: inverse impedance ratios shrink d c . It should be understood that a nonhamogeneous line according to the present invention will permit an increase in the optimized length as long as Z o increases in the direction from the signal generator to the signal receiver. Accordingly, the particular relationships between the characteristic impedances of the sub-lines shown above are intended to be used only for illustrative purposes. It is further important to understand that the nonhomogeneous line effords smaller delay times even if it exceeds slightly or substantially differs from the optimization value. Thus, even when it is not possible to achieve an optimized transmission line structure (A=1) in a particular application, a non-homogeneous construction may be employed to substantially reduce the transmission delay for signal transmissions in a particular direction. For example, while homogeneous "lossy" transmission lines in an SCB have a delay which is proportional to the square of the line length, an almost linear relationship between the transmission delay and the line length can be achieved with a directionally specific nonhomogeneous or cascaded transmission line Specifically, a plurality of signal conductor lines or line sections may be interconnected together in a way which will cause Z o to increase in the direction from the signal generator to the signal receiver. One way in which the variation in Z o may be achieved is to provide signal conductor lines of varying width, with the widest line being connected to the signal generator and the thinnest line being connected to the signal receiver. Of course, it will be appreciated that other suitable construction techniques may be employed in the appropriate application to achieve the desired variation in Z o . However, in one form of an SCB according to the present invention, conductor lines of varying width are deposited or formed on two different planes of the structure to facilitate connections with one or more IC chips. In this regard, FIG. 6 shows an interconnected conductor network 100 in which the widest conductor 102 is disposed on the same plane that the thinnest conductor 104 is disposed on. The conductors 102 and 104 are interconnected by the conductor 106 of intermediate width which is disposed on a plane below these two conductors. Any suitable means may be used to interconnect these conductors, such as amorphous silicon bridges 108 and 110. With this construction, it will be appreciated that both the conductors 102 and 104 are readily accessible to one or more IC chips which may be disposed in the vicinity above them. Thus, for example, a signal generator and a signal receiver may be disposed on the same IC chip or on different IC chips. FIG. 6 also shows that the conductor 102 is orthogonal to the the conductor 106, and that the conductor 106 is orthogonal to the conductor 104. This orthogonality permits logic nets to be created for interconnecting various IC chips disposed on the SCB substrate. However, it should be appreciated that other suitable angular relationships between the various conductors in the SCB matrix may be employed in the appropriate application. It should also be noted that the conductor 102 is shorter than the conductors 104 and 106. The use of such a short and fat conductor 102 is advantageous from the standpoint of the topology of an SCB strip-line conductor matrix. Since the strip-line conductors in an SCB matrix typically run across the entire length of the wafer, the use of a long and wide conductor would consume a substantial amount of space on the top interconnection plane of the SCB. However, by making the widest conductors very short (e.g., 1/3 of the normal length), it will be much easier for an SCB designer to permit a sharing of the space between the widest and thinnest conductors on a single plane. While it would be more desirable to have the widest conductor 102 on a plane which is between that of the conductor 106 and the ground path from the standpoint of capacitive coupling, this difference can be made up by an appropriate adjustment to the width and/or height of the conductor 102. It should be noted that the conductor network 100 will decrease signal transmission delays, even though the RC coupling of the individual conductors 102-106 with the ground plane is the same. Thus, for example, the width and height of the conductors 102-106 can be constructed such that each of these conductors will provide the same RC time constant. However, as shown above the increase in speed is due to the change in impedance through the conductor network 100. Specifically, as a signal is transmitted from conductor 102 to conductor 104, the impedance level increases and correspondingly the load decreases. Referring to FIG. 8, an enlarged top view of a portion of the SCB 10 of FIG. 1 is shown. FIG. 8 illustrates one possible form of an SCB structure which generally utilizes the type of conductor network shown in FIG. 6. Specifically, a plurality of relatively short and wide micro-strip conductors 112 and plurality of relatively long and thin micro-strip conductors 114 run parallel to each other and are disposed on the same plane of the SCB 10. Additionally, SCB 10 includes a plurality of micro-strip conductors 116 which are orthogonal to conductors 112-114, and which are disposed on a plane below that of the conductors 112-114. Amorphous silicon dioxide vias or bridges are used to provide programmable interconnections between these conductors at cross-over points shown as dots in FIG. 8. Each of the conductors 112-114 are connected to at least one of the plurality of pads 118 which are used to facilitate connections between the IC chips and the appropriate conductors of the SCB. Accordingly, it should be appreciated that one or more of the conductors 112 may be connected to a signal generator and one or more of the conductors 114 may be connected to a signal receiver. Then, the appropriate amphorous silicon dioxide bridges may be programmed to interconnect the conductors 112 and 114 together. In this regard, any suitable means may be employed to program these interconnections (e.g., through electrical, optical or thermal processes). FIG. 8 also illustrates that the SCB 10 includes a plurality of signal input and output pads 120-122, as well as test pads 124. Additionally, the SCB 10 includes a plurality of voltage and ground pads 126-128 which are disposed at various places along the top surface of the SCB to enable power connections to be made with the IC chips. It should be appreciated that FIG. 8 illustrates only one possible topology, and that other suitable SCB topologies may be employed in the appropriate application. The various embodiments which have been set forth above were for the purpose of illustration and were not intended to limit the invention. It will be appreciated by those skilled in the art that various changes and modifications may be made to these embodiments described in this specification without departing from the spirit and scope of the invention as defined by the appended claims.

A method and apparatus for optimizing the signal transmission speed between a signal source and a signal receiver of a microelectronic circuit is disclosed. The method includes the step of providing a signal transmission path whose length provides a predetermined ratio between its resistance and characteristic impedance which will reproduce the transmitted signal at the receiving end upon the first signal transition. The length of this transmission path may be increased by using a nonhomogeneous line structure in which the characteristic impedance increases in the direction of the signal transmission. In one form of the invention, the signal transmission path is formed by interconnecting a plurality of micro-strip conductors disposed on different planes of a universally programmable silicon circuit board. Under the appropriate circumstances, a signal can travel through such a "semi-lossy" transmission path at approximately the speed of light.

CROSS-REFERENCE Applicant claims priority from U.S. Provisional Application Ser. No. 60/526,677 filed 3 Dec. 2003. BACKGROUND OF THE INVENTION When hydrocarbons are produced from underground hydrocarbon reservoirs (which may also lie under a sea), the pressure and production rate tends to fall unless a fluid such as water is injected into the reservoir. Sea water is probably the most common injected fluid used in the production of hydrocarbons from undersea reservoirs, although water produced along with hydrocarbons from a reservoir may be reinjected. Sea water generally has about 10 ppm (parts per million) of dissolved oxygen. Once the water is pumped to high pressurize for reservoir injection, oxygen in the water can cause rapid corrosion of many of the steels commonly used in the construction of the system. The oxygen also feeds undesirable biological activity in the reservoir. As a result, it is common to reduce the amount of oxygen before it is pressurized and injected. One way to remove the oxygen is to reduce the pressure of the water so that dissolved gases break out of solution, and to then separate these two phases under normal gravity separation in a vertical tower filled with packing. This equipment is comparatively large. An apparatus and method that reduces the overall size and weight of the necessary equipment would be of value for the offshore oil industry where provisions for space and weight have a significant cost. SUMMARY OF THE INVENTION In accordance with one embodiment of the present invention, applicant provides an apparatus and method for separating gas from liquid, and for reducing oxygen in water that is to be injected into a hydrocarbon reservoir. A fluid stream which is a combination of water and dissolved gases, passes into a main conduit where its pressure is reduced to cause dissolved gases to break out of solution. The resulting mixture of water and gases is centrifuged to move gas to the center of the conduit and water to the periphery. A gas pipe inlet portion lies at the center of the water conduit at a location closely downstream of the centrifuge, to remove gases from the fluid and pass them through the gas pipe and a vacuum pump to the atmosphere. The amount of oxygen in the water to be injected may be further reduced by injecting nitrogen into the fluid stream before the centrifuge separation, to cause nitrogen to be dissolved in the water and displace some of the other gases that include oxygen. When the water pressure is reduced, more gas breaks out of solution and the oxygen content is further reduced. The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified view of a gas/water separation system of one embodiment of the present invention. FIG. 2 is a simplified view of a gas/water separation system of another embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a system 10 with a main conduit, or water conduit, 12 with an inlet 14 that receives fluid 16 that is water that may have been filtered and that has dissolved gases. In the example to be described, the water is sea water (water with dissolved salts) with dissolved gases that consist primarily of air (21% oxygen, 78% nitrogen, 1% argon and trace amounts of other gases). It is the oxygen, which corrodes steels used in the construction of the water injection system, and which results in undesirable biological activity in a hydrocarbon reservoir, that is to be removed from the sea water. Where the fluid consists primarily of water, it sometimes will be referred to herein simply as “water.” The system of FIG. 1 applies a vacuum to water at the entrance 14 . This can be accomplished by a valve 18 upstream of the conduit. The restriction in flow caused by the valve is adjustable to regulate water pressure downstream of the valve. The reduced water pressure results in gases in the water coming out of solution and forming gas bubbles. The system of FIG. 1 includes a centrifuge device 20 formed by fixed blades that direct the incoming gas-liquid mixture to rotate while continuing to flow. Immediately downstream of the centrifuge device, the spinning fluid separates into gas at the center of the conduit and liquid at the outer or peripheral portion of the conduit. A gas removal pipe 30 has a gas pipe inlet portion 32 lying downstream of the centrifuge to remove gas from the mixture. The gas pipe inlet portion 32 is spaced slightly downstream from the centrifuge blades to allow the spinning fluid to separate. The remaining portion of the fluid mixture 34 , which has been treated so most of the gas has been removed, passes downstream along the conduit portion 36 . In many cases the treated fluid, or water 34 passes through an exit blade device 40 that removes the spin. According to the law of conservation of energy, the removal of spin recovers some pressure, so that a higher vacuum lies upstream of the device 40 . The water that has been treated to deoxygenate it, usually passes through a downstream pump 46 that injects it into an undersea hydrocarbon reservoir to maintain the pressure therein. Such pump is positioned below the conduit so the vertical water column in a downward portion 42 of the conduit provides a head or pressure at the pump to meet the required minimum suction conditions of the pump. This vertical height is typically 4 to 8 meters and depends on the pump design. In accordance with one aspect of the present invention, applicant applies a gas-drawing mechanism such as a vacuum pump 50 to the gas pipe 30 . The gas pipe could be provided with a simple hole at its upstream end 35 to take out gas. However, applicant prefers to use a perforated gas inlet portion 32 that withdraws gas along a distance in the water pipe that is greater than the diameter at the upstream gas pipe end. Although the diameter of the gas-containing region at the center of the water pipe may be larger than the diameter of the gas inlet 32 , all of the gas in the gas-containing region can readily flow into the gas pipe because of the vacuum being applied and the perforations in the side of the gas pipe inlet portion. It is possible to vary the level of the vacuum (the pressure below atmospheric, or below the pressure in the water pipe at a location upstream from the gas pipe inlet) applied by the vacuum pump 50 to remove a high proportion of the gas that is present while removing a minimum of the liquid. Some of the fluid drawn into the gas pipe inlet includes water droplets. The water should be removed before the fluid reaches the vacuum pump 50 . FIG. 1 shows a separator 52 located along the gas pipe 30 . The separator includes a chamber 60 that receives the fluid that has passed into the gas pipe. The fluid which is primarily gas, is preferably routed downward through gas pipe end 54 to chamber 60 so that the vacuum in the conduit is improved by an amount equal to the static head of fluid in the pipe 30 . The gas and liquid separate under gravity in the chamber 60 . Gas in the chamber is removed from the upper portion 56 of the chamber to avoid a pressure buildup in the chamber. FIG. 1 shows a water pipe 64 , pump 66 and a valve 68 through which the liquid is removed. A level transmitter 70 senses when the level of the liquid 62 drops below a certain level, and this signal is fed into a controller to maintain a fixed liquid level. The controller may regulate the water pump speed or regulate the opening of valve 68 in the water outlet line, so gas is not removed through the liquid removal pipe. The removed water passes along a path 74 that can lead to an atmospheric disposal location which may be a drain system or the open sea, or that can be otherwise handled. Sea water commonly contains 50 ppm (parts per million) of air which includes 10 ppm of oxygen. The water may be close to saturation with dissolved gases, so a reduction in pressure can lead to gas being released and forming gas bubbles. Atmospheric air consists of 21% oxygen, 78% nitrogen, 1% argon and trace amounts of other gases. Nitrogen normally does not react with hydrocarbons or steel and argon is inert, so they do not affect a reservoir of hydrocarbons. Thus, the reduction in the oxygen content of fluid injected into the reservoir is the major goal of the system. FIG. 2 illustrates a system 100 of the invention that further reduces the amount of oxygen in the injected fluid. In the system of FIG. 2 , nitrogen gas is injected from a source 102 into the water-gas fluid that lies in or that enters the water conduit. The nitrogen gas is mixed into the water and air mixture 16 and some of the nitrogen is dissolved in the water. The nitrogen dissolved in the water saturates the water with gas, and causes more of the gas to come out of solution when the water pressure is reduced. Some of the additional gas that comes out of the solution with water is additional oxygen. After gas bubbles are removed by the gas pipe inlet 32 , the fluid mixture 112 in the water conduit 12 now contains gas with a smaller amount of oxygen per cubic meter, although with the same or even a greater overall amount of gas in the water, and passes along a conduit portion 114 . Nitrogen can be obtained by liquefaction of air at moderate cost, and typically produces gas with 98% nitrogen. Other means of supplying nitrogen include pressurized bottles shipped to the site, and the reverse osmosis process. Instead of injecting the nitrogen into the fluid initially entering the water pipe, it is possible to inject nitrogen into the fluid after much of the air has been removed. In FIG. 2 applicant indicates in phantom lines that instead of a spinner he may use a second centrifuge 120 and a second gas pipe 122 with a second gas pipe inlet portion 124 connected to a second pump 126 . The second centrifuge is a barrier to water flow, and results in a vacuum in and downstream of the second centrifuge. Nitrogen may be injected only at location 130 which lies downstream of the first gas pipe inlet 32 , as by an injection pipe 132 . At the nitrogen injection location 130 , a considerable percent of the air has already been removed, so a high percent of the injected nitrogen will become dissolved in water and as a result of the two stages a higher percent of oxygen will be removed from the water. However, this requires establishing a vacuum at two locations ( 110 and 130 ). Thus, the invention provides a system and method for the separation of gas from a gas/liquid mixture, and which is especially useful in the removal of oxygen from water that is to be injected into a hydrocarbon reservoir. Water with air in it is flowed though a water conduit, through a conduit region of reduced water pressure so gas comes out of solution, and is rotated in the conduit region to cause air bubbles to move to the middle of the conduit from which they are removed. The mechanical separation efficiency of the gas withdrawal may be adjusted by varying the gas volume fraction to an optimum value depending on system operating pressure and specific geometry. The efficiency of gas withdrawal is increased by injecting nitrogen into the water conduit and mixing the nitrogen with the air before the water is centrifuged. The nitrogen increases the gas content of the water so more gas comes out of solution where the water pressure is reduced. It also is possible to first remove much of the air, then inject nitrogen to increase the amount of dissolved gas in the water, and then remove the gas again. To remove much of the remaining oxygen in water at location 42 , an oxygen scavenger chemical an be injected in the water at 43 . Such chemical can reduce the oxygen contact to zero by chemically reacting with the oxygen in a manner similar to that in a conventional tower deoxygenation system. Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents.

A water stream is treated to remove oxygen before injecting the water into an underground hydrocarbon reservoir. The water-oxygen mixture is separated by centrifugal action using fixed spin blades ( 20 ). Oxygen is removed from the center of the conduit through a gas pipe ( 30 ) coupled to a vacuum pump ( 50 ). Nitrogen may be introduced upstream of the centrifuge to dilute the water-gas solution to improve the efficiency of the gas-liquid separation.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a divisional of U.S. patent application Ser. No. 12/388,410, filed Feb. 18, 2009. FIELD OF THE INVENTION [0002] This invention relates generally to an adjustable hinge and, more particularly, to a hinge with an adjustment mechanism for controlling the opening angle of the hinge. BACKGROUND [0003] Most hinges designed for use in entry way doors or cabinet frames permit an opening angle 90 degrees or greater in order to permit sufficient access to the storage area for the user. Yet, there are some situations where it is desirable to use a hinge that restricts the angle to 90 degrees or less. For example, some households are equipped with a “sink” or “tip-out” tray mounted in an opening on the front panel of a kitchen sink cabinet, directly in-front of the sink tub. These types of tray mechanisms and their corresponding hinges are specially designed to permit the tray to pivot in and out of the tight space formed between the frame of the sink cabinet, counter top and sink tub. [0004] While hinges for sink trays are known in the art, such prior art hinges are in the form of scissor-type hinges, such as the first and second prior art hinges 100 , 101 shown in FIGS. 1 and 2 , respectively. The first and second prior art hinges 100 , 101 incorporate a complex system of levers, panels, pins and coil springs and are relatively expensive because of their complexity and the amount of material they use. These prior art hinges are also designed to be mounted to the side walls of the sink cabinet, which reduces the space available for the sink tray. [0005] Accordingly, it is desirable to have a hinge with a simple, compact and economical design that includes an adjustment mechanism for controlling the opening angle so it can be used in conjunction with cabinet or door systems—such as sink tray system or the like—where it is desirable to be able to adjust the permitted opening angle. SUMMARY [0006] In an embodiment, the hinge of the present application comprises a recessed cup and arm, the arm being pivotably connected to the cup. One end of the cup includes securing flanges adapted to engage a panel. At the opposite end of the cup a slanted rim is formed atop the recessed portion of the cup. [0007] In one form, a mounting plate is formed on one portion of the arm and is adapted to be fastened to a cabinet frame or other mounting structure. At the other portion of the arm, referred to herein as the second portion, the arm is bent in order to form a curl that winds around a hinge pin secured in the cup, thereby permitting the arm to pivot relative to the cup. As the arm pivots from a closed position to an open position, an opening angle A is formed between the outer surface of the cabinet frame and inner surface of the panel. [0008] An adjustable stopper disposed along a first axis X-X is threaded through a passage formed in the second portion of the arm. A second end of the stopper extends into the cup, and may be beveled in order to form a shoulder disposed at an angle relative to the first axis X-X. As the arm pivots to the closed position, the shoulder contacts the rim, whereby the rim operates as a abutment for the stopper. [0009] The hinge may be incorporated in a sink tray system where a sink tray or tip-out tray is mounted to the inner surface of the cabinet panel using fastening screws or the like. It will be appreciated that the hinge and its corresponding adjustment mechanism permits the tray to pivot in and out of the tight space formed between the fame of the sink cabinet, counter top and sink tub. BRIEF DESCRIPTION OF THE DRAWINGS [0010] For the purpose of facilitating an understanding of the subject matter sought to be protected, there is illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages, should be readily understood and appreciated. [0011] FIG. 1 is a partial cross-sectional view of a first prior art sink tray hinge. [0012] FIG. 2 is a partial cross-sectional view of a second prior art sink tray hinge. [0013] FIG. 3 is a partial cross-sectional view of an embodiment of the hinge of the present application where the hinge is shown in the closed position. [0014] FIG. 4 is a partial cross-sectional view of the hinge of FIG. 3 , but showing the hinge in the open position. [0015] FIG. 5 is an enlarged partial cross-sectional view of the hinge of FIG. 4 , but showing the components of the self-closing/self opening functions in more detail. [0016] FIG. 6 is a partial plan view of the hinge of FIG. 4 . [0017] FIG. 7 is a partial cross-sectional view of the hinge of FIG. 3 incorporated with a typical sink tray system having a tray, frame and panel. [0018] FIG. 8 is a partial cross-sectional view similar to FIG. 7 , but showing the hinge in the open position. [0019] FIG. 9 is an enlarged front view of an embodiment of a multi-adjustable hinge. [0020] FIG. 10 is an enlarged front view of an embodiment of a safety bracket. [0021] FIG. 11 is a perspective view of the safety bracket of FIG. 10 incorporated with a typical sink tray system. DETAILED DESCRIPTION [0022] While the present invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to embodiments illustrated. [0023] Referring to FIGS. 3-8 , there is illustrated a hinge 10 comprising a recessed cup 13 and an arm 30 extending into the cup 13 . The cup 13 is inserted into a bore 19 formed in a cabinet panel 200 or the like. In one form, one end of the cup 13 includes securing flanges 17 extending outwardly from opposing sides of the cup 13 . Each flange 17 may include an aperture for receiving fastening screws 18 or the like for sercurment to cabinet panel 200 . At the opposite end of the cup 13 a slanted rim 15 is formed atop a recessed portion 14 of the cup 13 . It will be appreciated that the cup 13 can be formed in many ways, such as, for example, from a single pressed piece of sheet metal or casting. [0024] In an embodiment, arm 30 has a first portion 31 and second portion 34 . The first portion 31 includes a mounting plate 32 adapted to be secured over a frame 250 or other mounting structure, such as those found in typical sink cabinets or the like. The second portion 34 of the arm 30 extends into the cup 13 . In one form, the second portion 34 terminates in a curl 35 that winds around a hinge pin 40 secured in the cup 13 , thereby permitting the arm 30 to pivot relative to the cup 13 . As the arm 30 pivots from a closed position to an open position, an opening angle A is formed between the outer surface of the cabinet frame 250 and inner surface of the panel 200 . It will be appreciated that the arm 30 , including the first and second portions 31 , 34 may be pressed or cast from a single piece of sheet metal having multiple bends. [0025] The end of the curl 35 is notched in order to define opposing projections 36 . A coil spring 60 winds around a second pin 70 secured in the cup 13 and includes two legs 62 that extend toward and engage projections 36 . It will be appreciated that the interaction between the legs 62 of the coil spring 60 and projections 36 effectuate a self-opening and self-closing function. In particular, as the arm 30 pivots from the closed position toward the open position the free ends of the legs 62 pass over corners 37 of the projections 36 generating a moment force which biases the arm 30 towards the open position. Likewise, as the arm 30 pivots from the open position toward the closed position, the free ends of the legs 62 pass over corners 37 of the projections 36 generating a moment force which biases the arm 30 towards the closed position. [0026] Referring to the embodiments shown in FIGS. 3-8 , an adjustable stopper 50 extending along a first axis X-X is threaded through a passage 38 formed in an intermediate portion of the arm 30 . The stopper 50 may be in the form of a machine screw with a first end 52 in the form of a Phillips drive head or the like, although other structures for stopper 50 may be used as well. The passage 38 penetrates and extends slightly beyond the thickness of the arm 13 in order to permit a sufficient number of threads 39 to be engaged by the stopper 50 . Preferably, at least 3 or 4 thread 39 rotations should formed in the passage 38 to ensure the stopper 50 doesn't slip or otherwise disengage during normal operation. [0027] In an embodiment, a second end 55 of the stopper extends toward the cup 13 . The termination of the second end 55 may be beveled or chamfered in order to form an angled cross section having a shoulder 58 disposed at an angle relative to the first axis X-X. As the arm 30 pivots to the closed position, the shoulder 58 contacts the rim 15 , whereby the rim operates as an abutment surface for the stopper 50 . In one form, the cup 13 and stopper 50 are shaped such that the contacting surfaces of the shoulder 58 and rim 15 are disposed substantially parallel to each other to provide increased reliability by decreasing component wear. In that regard, such an arrangement maximizes the area of contact between the shoulder 58 and rim 15 , which prevents excess pressure and denting of the rim 15 . [0028] As shown in FIGS. 7-8 , the hinge 10 may be incorporated in a typical sink tray system 100 where a sink tray or tip-out tray 210 is mounted to the inner surface of the cabinet panel 200 using fastening screws or the like. The fact that the stopper 50 acts to restrict opening angle A permits the tray 210 to pivot inwardly and outwardly of the generally tight space formed between the frame 250 of the sink cabinet, counter top (not shown) and sink tub (not shown). [0029] In a method for installing the hinge 10 in a sink tray system 100 , the user begins by inserting the cup 13 into a bore 19 formed in an inner surface of a cabinet panel 200 and securing the flanges 17 to the panel 200 using fastening screws. In a sink tray system 100 incorporating two hinges 5 , one hinge 10 is installed on each end of the inner surface of the panel 200 , and each of the steps below are repeated for each hinge 10 . [0030] The user may then secure the mounting plate 32 to a surface of the frame 250 , also using fastener screws or the like. The opening angle A, (i.e. range of opening) can be controlled by manually rotating the stopper 50 using a screw driver or the like, which, depending on the direction of rotation, causes the stopper 50 to thread towards the cup 13 along the first axis X-X, or away from the cup 13 , also along the first axis X-X. It will be appreciated that the permitted opening angle A is minimized when the stopper 50 is fully inserted. In an embodiment, the desired opening angle A-A, may be between 20 and 70 degrees, depending on how far the user desires the tray 210 to tip outwardly toward the user. For example, a opening angle A-A too large (generally greater than 90 degrees) may permit the contents of the tray 210 to spill out, while a opening angle A-A too small may fail to permit the user sufficient access to the contents within the tray 210 . [0031] Securement of the tray 210 to the inner surface of the panel 200 is achieved by applying fasteners, such as a screw, to mounting slots (not shown) formed on the opposing surface of the tray 210 . It will be appreciated that the cup 13 is substantially recessed in the bore 19 and may be arranged to lay substantially flush with an inner surface of the panel 200 , thereby permitting additional space for the tray 210 along the inner surface of the panel 200 . It will also be appreciated that in a fully assembled sink tray system 100 , hinge 10 is substantially concealed behind the panel 200 for aesthetic purposes. Also, in one form, the hinge 10 of the current application permits the tray 210 to be sized in a manner that takes full advantage of the space available in the sink cabinet. In that regard, the tray 210 can be sized to extend substantially the full distance between the side walls 103 . [0032] In one form, the sink tray system 100 may further comprise a safety bracket 410 mounted at either end of the panel 200 to protect against safety hazards associated with excess force being applied to the panel 200 or tray 210 . For example, an unattended child who grasps the panel 200 or tray 210 in an attempt to swing or climb may cause forces to be applied to the hinge 10 beyond its weight capacity, which could result in breakage of the hinge 10 at the hinge pin 40 or the like, thereby creating a potential safety hazard. Accordingly, referring to FIGS. 10 , 11 safety brackets 410 may be mounted at either end of the panel 200 . In one form, the safety bracket 410 comprises an extension 440 with a foot 420 at one end and a catch 450 at the other end. The foot 420 may be provided with two apertures 425 that receive wood screws 430 for fastening the safety bracket 410 to the panel 200 . The catch 450 may be in the form of a dowel or the like and can be secured to the extension 440 by means of a machine screw that engages an aperture, as shown in FIG. 11 . The safety bracket 410 should be positioned on the panel 200 in a manner that causes the catch 450 to overlap with a vertical member 255 of the cabinet frame 255 . In this form, as the hinge 10 and panel 200 pivot toward the open position, the catch 450 is positioned to abut the inner surface of the vertical member 255 of the cabinet frame, thereby preventing the panel 200 from pivoting too wide relative to the vertical member 255 . [0033] In an alternative embodiment shown in FIG. 9 , a multi-adjustable hinge 310 may incorporate a two-piece adjustable arm 330 having a mounting plate 332 and jacket 331 having sleeves 333 folded from a single piece of sheet metal. The sleeves 333 are adapted to slideably engage a lower portion 334 that extends into the cup 13 . An elongated opening 339 centered in the lower portion 334 is sized to receive an adjustment screw 341 adapted to pass through the elongated opening 339 towards an aperture (not shown) in the rear portion of the jacket 331 . In one form, threads formed in this aperture are sized to threadably engage the threads of the adjustment screw 341 in a well known manner. The adjustable stopper 50 is threadably engaged through the passage 38 , which is substantially centered in the lower portion 334 of the arm below the elongated opening 339 . It will be appreciated that the cup 13 , spring loaded self-opening and self-closing and angle adjustment features of the alternative embodiment shown in FIG. 9 operate with a design and structure substantially the same to those shown in the embodiment of FIGS. 3-8 . [0034] In operation of the alternative embodiment shown in FIG. 9 , loosing of the adjustment screw 341 enables the jacket 331 and mounting plate 332 to shift vertically relative to lower portion 334 , thereby permitting vertical adjustment of the surfaces relative to each other to which the mounting plate 332 and cup 13 are attached. For example, the additional adjustment feature of the multi-adjustable hinge 310 may permit vertical adjustment of the cabinet frame 250 relative to the panel 200 , should the multi-adjustable hinge 310 be used with the a typical sink tray system 100 , such as those shown in FIGS. 7-8 . The adjustment screw 334 can be turned for tightening purposes in order to prevent movement of the mounting plate 332 relative to the lower portion 334 when they have reached their desired relative positions. [0035] It will be appreciated that while the components of the adjustable and multi-adjustable hinges 10 , 310 are made of cold rolled steel in one form, other sufficiently rigid materials may also be used, such as plastics or metals. [0036] The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be appreciated that changes and modifications may be made without departing from the broader aspects of applicants' contribution.

A hinge, comprising a cup having a rim and an arm pivotably connected to the cup, wherein the arm is permitted to pivot between a closed position and an open position, the open position defining a opening angle between the cup and arm. An adjustable stopper coupled to the arm is engagable with the rim whereby the opening angle is controlled by adjustment of the stopper.

FIELD OF THE INVENTION The present invention refers to a method for the determination of the physical features of a tire, for example the deformation that it undergoes during use. BACKGROUND OF THE INVENTION Recently the safety of the cars has increased due to the installation of various types of sensors and to related electronic control systems. Tires are also under study to avoid wear and possible explosions, which can of course create problems to motor vehicle occupants. Normally the deformation of the tread is measured by application of sensors to the tires, and measurement systems provide data related to the contact condition of the tire with the road. A method that uses the structure of the tire as a sensor is described by the article of A. Todoroki, S. Miyatani, and Y. Shimamura, Wireless Strain Monitoring Using Electrical Capacitance Change Of Tire: Part I With Oscillating Circuit”, Smart Material And Structure , Institute of Physics Publishing, No. 12, pp. 410-16, 2003. The article describes a measurement method of tire deformation that uses the tire steel wires as electrodes of a capacitor. The steel wires are connected to an oscillating circuit of the LC type, and the frequency variations of the oscillator correspond to the variations of the capacitor capacity. SUMMARY OF THE INVENTION In view of the state of the art described, it is an object of the present invention to provide a measurement method of the physical features of a tire that has a higher precision and is able to give further information in comparison with the known methods. According to the present invention, such an object is achieved by means of a method for the determination of the physical features of a tire, said tire comprising at least a first belt reinforced with a plurality of metallic wires, including providing a signal between a first and a second metallic wire and determining the real part and the imaginary part of the impedance between said first metallic wire and said second metallic wire. According to an embodiment of the present invention, it is possible to get important information from tire resistance variations. By measuring both the capacitance and the resistance of the tire, it is possible to have a better interpretation of tire deformation. According to an embodiment of the present invention, it is possible to carry out the measurements both on the wires of the same belt and on the wires of different belts, in this way interpreting the best obtainable information. The measurement of the resistance combined with that of the capacitance allows a better appraisal of the thickness variations of the belts and as well as those of a single belt. Two characteristic parameters of the tire are used in an embodiment of the present invention, namely ∈ and ρ, wherein ∈ is the dielectric constant of the rubber in the tire, and ρ is the resistivity of the rubber in the tire. According to the present invention, resistance is related to the temperature assumed by the tire, and therefore by measuring the real part of the tire impedance it is possible to get information on the temperature variation of the tire. BRIEF DESCRIPTION OF THE DRAWINGS The features and the advantages of the present invention will be made more evident by the following detailed description of a particular embodiment, illustrated as a non-limiting example in the annexed drawings, wherein: FIG. 1 shows a perspective view of a partial structure of a tire; FIG. 2 shows a schematic representation of the tire belts; FIG. 3 shows a measurement system of an impedance matrix; and FIG. 4 shows a graph in which the capacitor value variations are represented with respect to a sample deformation. DETAILED DESCRIPTION A tire, as shown in FIG. 1 , comprises a carcass 1 having a toroidal shape including at least a material layer reinforced with wires placed in radial planes and a tread 2 placed above the carcass 1 . Between the carcass 1 and the tread 2 , two belts 3 and 4 are placed. Every belt includes a reinforced rubber layer with steel wires that are parallel to each other. Belts 3 and 4 have steel wires tilted with respect to the equatorial plane of the tire, normally of about 20°, and they are placed so that the wires of a belt intersect the wires of the other belt. That is, if the wires of a belt are tilted toward the right, the wires of the other belt are tilted toward the left, and therefore they form an angle of about 40° with respect to each other. The force between the tire and ground can be represented by a vector with two components. One component is perpendicular to the contact surface and one is tangential to the contact surface. The tangential component can subsequently be divided in a parallel component and a perpendicular component with respect to the equatorial plane of the tire. Reference is now made to FIG. 2 where belts 3 and 4 are schematically represented. For every belt, the reinforcement wires are shown in schematic form, which in this case form an angle of 90° with each other. Specifically, belt 3 includes wires 10 and belt 4 includes wires 11 . Impedances are represented, composed of a resistance and a capacitor in parallel, between the wires belonging to the two belts as the resistance RT and the capacitor CT and impedances between the wires belonging to the same belt like the resistance RC and the capacitor CC. Consider, for example, the wires in the same belt. The coupling between the two electrodes, represented by the wires, behaves as a distributed capacitor, while the rubber in the middle behaves as a resistance. The capacitor can be calculated by the following relation: C = ɛ ⁢ S d where ∈ is the dielectric constant of the rubber, S is the area between the two faced electrodes and d is the distance between the electrodes. The resistance can be calculated by the following relation: R=ρd where ρ is the resistivity of the rubber and d is the distance between the electrodes. When a tire meets an obstacle, the deformation of the tread is transferred to the reinforcement wires of belts 3 and 4 . The deformation causes a variation of the space between the wires, and this variation is translated into a variation of the capacitance and resistance values. For example, when the wire lengthens, the distance d increases and the capacitance decreases while the resistance increases. By measuring the impedance variations it is then possible to determine the tire deformation, and since the movement is proportional to the force, it allows a measure of the forces applied to the tire. Impedance measurement systems are known in the art, as well as systems to determine, in a particular case, the resistance value and the capacitor value. An example of a measurement system is shown in FIG. 3 . The following description refers to the case in which the impedance is measured between the wires of two belts. A switching system 20 allows the selective application of the signal coming from a generator G to the wires 11 of belt 4 . A switching system 21 allows the selective application of a charge amplifier A to the wires 10 of belt 3 . Preferably, the wires to which the signal has not been applied or to those to which the amplifier A is not connected, are connected to ground by switching systems 20 and 21 . The signal received by wires 10 is applied to the non-inverting input of amplifier A, the inverting input is connected to ground, and a capacitor CF and a resistance RF are coupled between the inverting input and the output. The transfer function of the measuring circuit is the following: V 0 Vi ⁢ ( j ⁢ ⁢ ω ) = - Rf Rt ⁢ ( 1 + j ⁢ ⁢ ω ⁢ ⁢ R T ⁢ C T 1 + j ⁢ ⁢ ω ⁢ ⁢ R F ⁢ C F ) where V 0 is the output voltage of wires 10 , and Vi is the input voltage. In a low frequency range, for example of the order of several kHz, ω<<1/(RTCT) and ω<<1/(RFCF) and the preceding relation can be rounded to V 0 /Vi=−(RF/RT). Therefore, it is possible to determine the resistance value, which is the real part of the impedance. In a high frequency range, for example of the order of several MHz, ω>>1/(RTCT) and ω>>1/(RFCF) and the preceding relation can be rounded to V 0 /Vi=−(CT/CF). Therefore it is possible to determine the value of the capacitor, which is the imaginary part of the impedance. By means of switching systems 20 and 21 , all the wires can be scanned and, in this way, a map of the tire mechanical deformation can be created. The mechanical deformation map of the tire is thus formed by sequentially scanning every couple of metallic wires according to the present invention. Measurements can be made on a tire sample comprising two belts. An electrode is applied to a wire of a belt and another electrode is applied to a wire of the other belt. An LCR impedance meter is used to measure the impedance, and a strain meter is used for measuring the tensile force applied to the sample. In FIG. 4 the capacitor value variations with respect to the deformation of the sample are shown. Particularly, on the x-axis the component of the perpendicular force to the equatorial plane of the tire is shown, measured in mm. On the y-axis the corresponding variation of the capacitance is shown, measured in nF. As the tensile force increases, the thickness of the sample decreases, as well as the distance between the electrodes. Accordingly the capacitance increases. The increasing capacitance saturates for a tensile force equal to about 2.5 μm due to the presence of tire reinforcement structures. It has been noticed that a deformation of 0.6% of the linear dimension of the tire causes about a 7% variation in the capacitance. Another measured tire sample included only a single belt, and therefore the resistance is measured between the electrodes of the same layer of the belt. The tensile force is statically applied between 0 and 3 mm. Because of the linear deformation, the distance between the electrodes increases, the thickness decreases, and the resistance increases. Using a single belt there are no further reinforcement structures of the tire and therefore there is no saturation effect. The results of the measurements are reported in Table 1. TABLE 1 Extension of the Extension of the Extension of the sample of 1 mm sample of 2 mm sample of 3 mm Measured 2300 2340 2380 resistance (Ω) A further tire sample comprising two belts of the type previously used has been measured. Tensile forces are applied for the duration of one second. It has been noticed that the impedance measurement instantly changes with the force application. The impedance measure, therefore, reaches its static value, demonstrating that the relation between the impedance and the tensile force is linear. While there have been described above the principles of the present invention in conjunction with a preferred embodiment, it is to be clearly understood that the foregoing description is made only by way of example and not as a limitation to the scope of the invention. Particularly, it is recognized that the teachings of the foregoing disclosure will suggest other modifications to those persons skilled in the relevant art. Such modifications may involve other features which are already known per se and which may be used instead of or in addition to features already described herein. Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure herein also includes any novel feature or any novel combination of features disclosed either explicitly or implicitly or any generalization or modification thereof which would be apparent to persons skilled in the relevant art, whether or not such relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as confronted by the present invention. The applicants hereby reserve the right to formulate new claims to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom.

A measurement technique determines the physical features of a tire such as a determination of the deformation a tire undergoes during use. The measurement technique utilizes a first belt, or first and second belts, in the tire reinforced with a plurality of metallic wires and involves the steps of providing a signal between a first and a second metallic wire associated with the first or first and second belts. The measurement technique determines a real part and an imaginary part of the impedance between the first and second metallic wires, which is proportional to the forces acting on the tire.

TECHNICAL FIELD [0001] The present invention relates to the field of data center cooling. More particularly, it relates to the enhancement of cooling air flow to the machines in a data center. RELATED ART [0002] The growth of computer networking, and particularly the rapid growth of the use of the Internet, has resulted in a rapid increase in demand for server computers. Most commonly, a number of modular server units, for example the modular computing units known as “blade” servers, are removably mounted in equipment racks. Typically a large number of such racks are housed in a building known as a data center. In a data center, one or more large rooms are provided. Each room houses rows of equipment racks and their mounted servers, and associated cabling and network communication equipment. [0003] A modern rack when fully loaded with blade servers consumes a large amount of electrical power when operating. In consequence, a large amount of waste heat is produced. Many data centers now employ individual racks of blade servers in which each rack develops 20 kW or more of waste heat. To avoid damage to the servers by overheating, this waste heat must be removed. [0004] In a commonly used arrangement, data center rooms are cooled by computer room air conditioning units (termed CRACs) which circulate cooled air which passes through the rack units for heat removal. Typically, a data center room comprises a raised floor above a plenum chamber through which cooled air is blown by CRAC units. Rows of server racks are mounted on the floor separated by aisles. Networks of grilles in the floors of the aisles between rows of server racks allow cooled air from the plenum to rise into the aisles. From here it is typically drawn through the front of the racks by fans mounted in the racks. Heated air passes out of the other side of the rack and is drawn up into a roof plenum chamber for removal or recirculation through the CRAC units. In a commonly used arrangement, an aisle comprises two rows of server racks whose fronts face each other with the floor of the aisle space between the two rows of server racks comprising a number of grilles through which cooled air rises. This is termed a cold aisle. Behind each row of racks is a hot aisle to which heated air passes after flowing through the racks and then rises for removal by way of the roof plenum chamber. [0005] Maintaining the free flow of cooling air is vital for maintaining the temperatures of all the blade servers within acceptable operational limits. However, there are times when the introduction of obstructions into aisles is unavoidable. For example, it is sometimes necessary to provide a shelf for the support of a keyboard and display of a server unit installed for the purpose of performing hardware management operations on the other installed servers. This is known as a hardware management console or HMC. The shelf is typically installed in a horizontal rack slot at a height convenient for use by a maintenance operator. The shelf runs on rails so that it may be pulled out from the front of the rack to form a horizontal management operations shelf. It includes a horizontal keyboard and behind this a flat screen display. The display is horizontal when in a stored position in the rack but moveable to a near vertical position to provide a display interface to the HMC when the shelf is withdrawn from the rack into an operating position. [0006] During operation of the HMC, the shelf extending from the rack front forms a barrier to vertically rising cooling air in the cold aisle. The supply of cooling air is an energy intensive operation. It is therefore desirable to optimize the supply of cooling air to provide just enough to maintain efficient server operation at every position in the rack. Any obstruction of flow by a shelf will restrict the supply of cooling air supply to blade servers in the rack above the shelf. This is likely therefore to result in the overheating of these blade servers. It would be desirable to provide a solution to the problem of restricted air flow resulting from the use of a shelf protruding from the front of a rack, such as when using a HMC. [0007] U.S. Pat. No. 6,801,428 discloses an arrangement for cooling a series of closely spaced upright computer components mounted to a support, the arrangement including a tray having a plurality of air moving devices such as fans. Members are used for helping removably mount the tray to the support in a generally horizontal disposition, and the air moving devices move air in a generally upright path of travel to help cool the upright computer components. The tray also has a series of connector ports for connecting electrically to outputs from individual ones of the computer components. SUMMARY OF THE INVENTION [0008] Viewed from a first aspect, the invention provides a rack system for mounting at least one data processing unit, the rack system comprising a shelf operable for moving from a position internally of the rack system to a position externally of the rack system. The shelf comprises an aperture in the shelf and a fluid mover for moving fluid through the aperture in the shelf when the shelf is located in its external position. [0009] In an embodiment of the rack system, the fluid mover is an air mover. [0010] In an embodiment of the rack system, the shelf is mounted on rails operable for moving the shelf from the position internally of the rack system to the position externally of the rack system. [0011] In an embodiment of the rack system, the air mover is operable for moving air from below the shelf. [0012] In an embodiment of the rack system, the air mover comprises at least one fan. [0013] In an embodiment of the rack system, the external position is an operating position of the shelf. [0014] In an embodiment of the rack system, the shelf comprises a hardware management console. [0015] Viewed from a second aspect, the invention provides a shelf for mounting in a rack system, the rack system for mounting at least one data processing unit, the shelf being operable for moving from a position internally of the rack system to a position externally of the rack system. The shelf comprises an aperture in the shelf and a fluid mover for moving fluid through the aperture in the shelf when the shelf is located in its external position. [0016] In an embodiment of the shelf, the fluid mover is an air mover. [0017] In an embodiment of the shelf, the shelf is mounted on rails operable for moving the shelf from the position internally of the rack system to the position externally of the rack system. [0018] In an embodiment of the shelf, the air mover is operable for moving air from below the shelf. [0019] In an embodiment of the shelf, the air mover comprises at least one fan. [0020] In an embodiment of the shelf, the external position is an operating position of the shelf. [0021] In an embodiment of the shelf, the shelf comprises a hardware management console. [0022] Viewed from a third aspect, the invention provides a method for supplying cooling fluid to a rack system, the rack system for mounting at least one data processing unit, the method comprising providing a shelf operable for moving from a position internally of the rack system to a position externally of the rack system. The shelf comprises an aperture in the shelf and a fluid mover for moving fluid through the aperture in the shelf when the shelf is located in its external position. [0023] In an embodiment of the method, the fluid mover is an air mover. [0024] In an embodiment of the method, the shelf is mounted on rails operable for moving the shelf from the position internally of the rack system to the position externally of the rack system. [0025] In an embodiment of the method, the air mover is operable for moving air from below the shelf. [0026] In an embodiment of the method, the air mover comprises at least one fan. [0027] In an embodiment of the method, the external position is an operating position of the shelf. [0028] In an embodiment of the method, the shelf comprises a hardware management console. BRIEF DESCRIPTION OF THE DRAWINGS [0029] Embodiments of the invention will now be described in detail by way of example only with reference to the following drawings. [0030] FIG. 1 is a cross-section of a prior art data center in which embodiments of the invention may be employed. [0031] FIG. 2 is a cross-section of an equipment rack as illustrated in the data center of FIG. 1 in which embodiments of the invention may be employed. [0032] FIGS. 3 a , 3 b and 3 c are perspective views illustrating the deployment of a hardware management console shelf according to the prior art. [0033] FIG. 4 is a cross section of a rack with a prior art hardware management console shelf deployed in its operational state. [0034] FIG. 5 is a perspective view illustrating an embodiment of the present invention. [0035] FIG. 6 is a cross-section of an equipment rack illustrating an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0036] FIG. 1 illustrates a cross-section of a data center room 100 suitable for incorporating embodiments of the present invention. A conditioning unit, for example a computer room air conditioning unit (CRAC) 110 , comprises chiller and blower components for, respectively, chilling and impelling fluid for circulating in the data center room. The circulating fluid functions for removal of heat generated by equipment operating in data center room 100 . In an embodiment, the circulating fluid is a gaseous fluid, for example the fluid is the ambient air of data center room 100 . In an embodiment, the CRAC 110 blows chilled air through a grille 115 a into a sub-floor plenum chamber 120 . The sub-floor plenum chamber 120 extends over substantially the whole floor area of data center room 100 . The floor 122 is suitably supported above the sub-floor plenum chamber 120 to carry rows of equipment racks such as equipment racks 140 a and 140 b as illustrated. The equipment racks 140 a, 140 b each comprise a rack framework suitable for mounting modular data processing units, for example server computing units such as blade servers. [0037] Air flows through the sub-floor plenum chamber 120 as shown by arrow 125 . Air flows from the sub-floor plenum chamber 120 up through grilles 115 b, 115 c into a cold aisle 150 a. From here air is drawn through the front of the racks 140 a, 140 b by air movers, such as fans, mounted within the racks 140 a, 140 b. The air flow 145 a, 145 b is shown entering the front of the rack 140 a and the air flow 145 c, 145 d entering the front of the rack 140 b. Air exits 155 a, 155 b from the rear of the rack 140 a into a hot aisle 150 b. Similarly, air exits 155 c, 155 d from the rear of the rack 140 b into a hot aisle 150 c. Air is then drawn upwards from the hot aisle 150 b through a grille 115 d in the roof 132 into a roof plenum chamber 130 . Similarly, air is drawn upwards from the hot aisle 150 c through a grille 115 e in the roof 132 into the roof plenum chamber 130 . The roof plenum chamber 130 extends over substantially the whole roof area of the data center room 100 . Air flows 135 through the roof plenum chamber 130 and re-enters the CRAC 110 by way of a grille 115 f. [0038] FIG. 2 illustrates an enlarged cross-section of the rack 140 a of FIG. 1 . Air is shown rising through the grille 115 c from the sub-floor plenum chamber 120 . Air enters 145 a, 145 b the front of the rack 140 a, drawn by air movers, such as fans, mounted within the rack 140 a. Air exits 155 a, 155 b from the rear of the rack 140 a. A typical arrangement of the rack 140 a is shown in which the rack 140 a is loaded with a plurality of substantially identical blade server units. The rack 140 is divided into vertical sections 210 a to 210 f. Each vertical section 210 a to 210 f comprises a plurality of vertically oriented blade servers each inserted on guide rails from front to back of the sections 210 a to 210 f. It will be understood that this is by way of example only. It will be understood that other arrangements are possible, for example using horizontally mounted data processing units mounted in the rack 140 a, or a mix of horizontally and vertically mounted data processing units. [0039] Also shown is a shelf unit 220 within the rack 140 a. The shelf unit 220 comprises a substantially flat horizontal unit, typically extending across substantially the whole of the width of the rack 140 a. The shelf unit 220 is mounted on rails attached to the framework of the rack 140 a and is operable for withdrawing from the front of the rack 140 a to provide a working surface for use by a human operator. The shelf unit 220 will therefore be mounted in the rack 140 a, for example at a height suitable for allowing comfortable use by a human operator, for example in a standing position. [0040] FIGS. 3 a to 3 c illustrate the deployment to an operating position of the shelf 220 suitable for incorporating embodiments of the present invention. In FIGS. 3 a to 3 c , the shelf unit 220 comprises a hardware management console, or HMC, which is an interface to a server unit installed for the purpose of allowing a human operator to perform hardware management operations on the other installed servers. In FIG. 3 a , the shelf unit 220 runs on rails 330 in the rack 140 a and is pulled out in direction 340 a from the front 310 of the rack 140 a. FIG. 3 b shows the shelf unit 220 fully extended. The HMC has a keyboard 350 and a flat screen display 360 . The screen 360 lies flat in a non-operational position as shown in FIG. 3 b when the shelf 220 is extracted from the front 310 of the rack 140 a. The screen 360 is raised to an operational position as shown by arrow 340 b. FIG. 3 c shows the shelf unit 220 with the HMC in an operational position. The shelf unit 220 provides a barrier to rising cool air 370 a. [0041] FIG. 4 illustrates a cross-section of the rack 140 a of FIG. 2 , but comprising the shelf unit 220 in an operating position fully extended from the rack 140 a. The shelf unit 220 comprises an HMC comprising the keyboard 350 and the display 360 . Air 145 a rises after passing through the grille 115 c from the sub-floor plenum chamber 120 . Air 145 a enters the front of the rack 140 a sections 210 d to 210 f and exits from the rear of the rack 140 a from sections 210 d to 210 f. The shelf 220 presents a barrier to the rising cool air 145 x. Consequently, the cool air flow 145 y which may enter the front of the rack 140 a at sections 210 a to 210 c is much reduced. Servers in the rack 140 a sections 210 a to 210 c are therefore at risk of overheating. [0042] FIG. 5 illustrates a shelf unit 520 extracted from the front 510 of a rack 540 a according to an embodiment of the present invention. The shelf unit 520 comprises an HMC comprising a keyboard 550 and a display 560 . The shelf unit 520 further comprises an aperture comprising a fluid mover. In an embodiment, the fluid mover comprises an air mover for moving air 570 a from below the shelf unit 520 through the aperture in the shelf unit 520 and exiting 570 b above the shelf unit 520 . In the embodiment illustrated in FIG. 5 , the air mover comprises fans 580 a to 580 d mounted within suitably shaped apertures in the shelf unit 520 . The fans 580 a to 580 d may, for example, be mounted within the apertures in the shelf 520 and not protrude substantially from upper or lower surfaces of the shelf 520 . The axes of rotation of the fan blades of the fans 580 a to 580 d may be orientated substantially vertically in relation to the rack 540 a. [0043] FIG. 6 illustrates a cross-section of the rack 540 a comprising an embodiment of the present invention. The shelf 520 is shown extended in an operating position. The shelf 520 comprises an HMC comprising a keyboard 550 and a display 560 . The shelf 520 comprises an aperture comprising a fluid mover, for example, an air mover. In the illustrated embodiment, the air mover comprises fans, 580 a and 580 b illustrated in cross-section. Air 645 a rises through a grille 615 c from a sub-floor plenum chamber 620 and enters the front of rack 540 a. Air 645 a passes over servers mounted in sections 610 d to 610 f of the rack 540 a and exits 655 a from the rear of the rack 540 a. Air 645 b is moved through the shelf 520 by the air mover, comprising fans 580 a and 580 b shown. Air 645 b enters the front of the rack 540 a and passes over servers mounted in sections 610 a to 610 c and exits 655 b from the rear of the rack 540 a. The shelf 520 therefore presents a reduced barrier to rising cooling air and servers in sections 610 a to 610 c receive an enhanced supply of cooling air so that the risk of overheating is reduced. [0044] In a further embodiment with reference to FIG. 2 , the shelf 220 comprises a simple shelf unit comprising an air mover in accordance with the present invention and does not comprise a HMC. In this embodiment it is possible to use the shelf unit to enhance the flow of cooling air. [0045] It will be apparent that although embodiments of the invention have been described in relation to a data center comprising racks comprising a plurality of blade server computing units, other arrangements are possible without departing from the invention. In further embodiments of the invention, other types of data processing units are employed. In one exemplary embodiment, data processing units comprise horizontally mounted modular units. In another exemplary embodiment, the rack comprises a small number of larger data processing units. In a further embodiment, data processing units comprise data storage units such as magnetic or optical disk data storage units.

A rack system for mounting at least one data processing unit includes a shelf operable for moving from a position internally of the rack system to a position externally of the rack system. The shelf has an aperture and a fluid mover for moving fluid through the aperture in the shelf when the shelf is located in its external position.

FIELD OF THE INVENTION [0001] The present invention relates to novel crystalline forms and salt forms of compounds that are useful as pharmaceutically active ingredients for the treatment of type 2 diabetes and other diseases that are modulated by PPAR gamma agonists, including hyperglycemia, obesity, dyslipidemia, and the metabolic condition. The invention also relates to a process for making the compounds, crystalline forms, and salts. BACKGROUND OF THE INVENTION [0002] Type 2 diabetes remains a serious medical problem. There is an ongoing need for new treatments that are more effective and that have fewer side effects. PPAR gamma agonists, including the two marketed products rosiglitazone and pioglitazone, are important medications for the treatment of type 2 diabetes. Treatment of a patient with PPAR gamma agonists improves insulin sensitivity, but the treatment is often accompanied by side effects, such as weight gain and edema. Selective PPAR gamma partial agonists, also known as selective PPAR gamma modulators (SPPARM's or SPPARgM's), are effective in reducing serum glucose with reduced weight gain and/or edema. SUMMARY OF THE INVENTION [0003] The present invention is concerned with novel crystal forms, salts, and crystal forms of the salts of a compound that is an active PPAR gamma partial agonist, and methods of making the compound, salts and crystal forms. The compound was originally disclosed as a solid in U.S. Provisional Application No. 60/658,661, now WO2006/096564, but the solid did not have the crystal form disclosed herein. The crystalline forms disclosed herein are novel and well characterized, and have advantages over the solid forms disclosed in WO2006/096564 that make them useful in preparing pharmaceutical formulations, such as ease of purification, ease of processing, and thermodynamic stability with respect to other forms of the compound. The anhydrous free acid crystalline form is non-hygroscopic, and exhibits good bioavailability in animals, even though it has low water solubility at neutral pH. [0004] The invention also concerns pharmaceutical compositions comprising the novel crystalline polymorphs; processes for the preparation of these polymorphic forms and their pharmaceutical compositions; and methods for using them for the treatment of type 2 diabetes, hyperglycemia, obesity, dyslipidemia, and the metabolic condition. BRIEF DESCRIPTION OF THE FIGURES [0005] FIG. 1 is a characteristic X-ray diffraction pattern of the crystalline anhydrous free acid form. [0006] FIG. 2 is a carbon-13 cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectrum of the crystalline anhydrous free acid form. [0007] FIG. 3 is a typical DSC curve of the crystalline anhydrous free acid form. [0008] FIG. 4 is a typical thermogravimetric (TG) curve of the crystalline anhydrous free acid form. [0009] FIG. 5 is a characteristic X-ray diffraction pattern of the crystalline anhydrous benzenesulfonate (besylate) salt. [0010] FIG. 6 is a typical DSC curve of the crystalline anhydrous besylate salt. DETAILED DESCRIPTION OF THE INVENTION [0011] In one embodiment, this invention provides a novel crystalline anhydrous polymorphic form of the free acid of (2S)-2-({6-chloro-3-[6-(4-chlorophenoxy)-2-propylpyridin-3-yl]-1,2-benzisoxazol-5-yl}oxy)propanoic acid (Compound I): [0000] [0012] This compound was first disclosed as Example 14 in WO 2006/096564. The compound that was isolated using the synthetic methodology in the above-mentioned PCT patent application does not have the crystal form that is disclosed herein. Improvements in the process for making the compound led to the discovery of a crystalline free acid anhydrate of Compound I, which is described and characterized herein. The invention also provides a benzenesulfonate (besylate) salt of Compound I, and more specifically, an anhydrous crystalline benzenesulfonic acid (besylate) salt of Compound I. The besylate salt, and specifically the anhydrous crystalline besylate salt, has advantageous properties compared with the non-crystalline free acid and amorphous sodium salts of Compound I that were originally made. The two crystalline compounds (crystalline free acid anhydrate and anhydrous crystalline besylate salt) are readily used in the preparation of pharmaceutical compositions. [0013] The benzenesulfonic acid (besylate) salt of Compound I is also a new composition of matter. This is generally referred to herein as the benzenesulfonic acid (besylate) salt of Compound I, but it can also be written as a chemical compound having Formula Ia: [0000] [0000] The compositions, drug substances, formulations, and pharmaceutical uses that are described herein for the crystalline anhydrous besylate salt are also representative of compositions, drug substances, formulations, and pharmaceutical uses of the besylate salt in general. [0014] A further embodiment of the present invention provides a drug substance that comprises the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt of Compound I in a detectable amount. By “drug substance” is meant the active pharmaceutical ingredient (API). The amount of crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt in the drug substance can be quantified by the use of physical methods such as X-ray powder diffraction (XRPD), solid-state fluorine-19 magic-angle spinning (MAS) nuclear magnetic resonance spectroscopy, solid-state carbon-13 cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance spectroscopy, solid state Fourier-transform infrared spectroscopy, and Raman spectroscopy. In a sub-class of this embodiment, about 5% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt is present in the drug substance. In a second sub-class of this embodiment, about 10% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt is present in the drug substance. In a third sub-class of this embodiment, about 25% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt is present in the drug substance. In a fourth sub-class of this embodiment, about 50% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt is present in the drug substance. In a fifth sub-class of this embodiment, about 75% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt is present in the drug substance. In a sixth sub-class of this embodiment, substantially all of the Compound I drug substance is the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt, i.e., the Compound I drug substance is the substantially phase pure crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt. [0015] Another aspect of the present invention provides a method for the treatment or control of clinical conditions for which a PPAR gamma agonist is indicated, which method comprises administering to a patient in need of such treatment or control a therapeutically effective amount of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt of Compound I or a pharmaceutical composition containing a therapeutically effective amount of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt of Compound I. Such clinical conditions include Type 2 diabetes, hyperglycemia, obesity, dyslipidemia, and metabolic syndrome. A “patient” is a mammal, including a human. A patient is most often a human patient. [0016] The present invention also provides for the use of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt of the present invention in the manufacture of a medicament for the treatment or control in a patient of one or more clinical conditions for which a PPAR gamma agonist is indicated. In one embodiment, the clinical condition is Type 2 diabetes. [0017] Another aspect of the present invention provides the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt for use in the treatment or control in a patient of one or more clinical conditions for which a PPAR gamma agonist is indicated. In one embodiment of this aspect the clinical condition is Type 2 diabetes. [0018] The present invention also provides pharmaceutical compositions comprising the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt, in association with one or more pharmaceutically acceptable carriers or excipients. In one embodiment the pharmaceutical composition comprises the active pharmaceutical ingredient (API) in admixture with pharmaceutically acceptable excipients wherein the API comprises a detectable amount of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt of the present invention. In a sub-class of this embodiment the pharmaceutical composition comprises the API in admixture with pharmaceutically acceptable excipients wherein the API comprises about 5% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt of the present invention. In a sub-class of this second embodiment, the API in such compositions comprises about 10% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt. In a sub-class of this embodiment, the API in such compositions comprises about 25% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt. In a sub-class of this embodiment, the API in such compositions comprises about 50% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt. In a sub-class of this embodiment, the API in such compositions comprises about 75% to about 100% by weight of the crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt. In a sub-class of this embodiment, substantially all of the API is crystalline free acid anhydrate or crystalline anhydrous benzenesulfonate salt of Compound I, i.e., the API is substantially phase pure Compound I in the crystalline free acid anhydrate form or substantially phase pure Compound I in the form of a crystalline anhydrous benzenesulfonate salt. [0019] The compositions in accordance with the invention are suitably in unit dosage forms such as tablets, pills, capsules, powders, granules, sterile solutions or suspensions, metered aerosol or liquid sprays, drops, ampoules, auto-injector devices or suppositories. The compositions are intended for oral, parenteral, intranasal, sublingual, or rectal administration, or for administration by inhalation or insufflation. Formulation of the compositions according to the invention can conveniently be effected by methods known in the art, for example, as described in Remington's Pharmaceutical Sciences, 17 th ed., 1995. [0020] The dosage regimen is selected in accordance with a variety of factors including type, species, age, weight, sex and medical condition of the patient; the severity of the condition to be treated; the route of administration; and the renal and hepatic function of the patient. An ordinarily skilled physician, veterinarian, or clinician can readily determine and prescribe the effective amount of the drug required to prevent, counter or arrest the progress of the condition or to treat or control the condition. [0021] Oral administration is the preferred method of administering the crystal forms and salt forms of Compound I described herein. The drug can be administered 1-2 times per day, with once daily being preferred. The daily dosage for an adult human patient is generally 1-25 mg, and preferably 2-10 mg administered once daily. [0022] In the methods of the present invention, the Compound I crystalline free acid anhydrate and the crystalline anhydrous benzenesulfonate salt described herein in detail can form the API, and are typically administered in admixture with suitable pharmaceutical diluents, excipients or carriers (collectively referred to herein as ‘carrier’ materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices. [0023] For instance, for oral administration in the form of a tablet or capsule, the active pharmaceutical ingredient can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, starch, sucrose, glucose, methyl cellulose, microcrystalline cellulose, magnesium stearate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the oral API can be combined with any oral, non-toxic, pharmaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, some natural sugars, corn sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, and the like. Disintegrants include, without limitation, starch, methyl cellulose, croscarmellose sodium, agar, bentonite, xanthan gum and the like. Surfactants, such as sodium lauryl sulfate, can also be included in the formulations. [0024] The following non-limiting Examples are intended to illustrate the present invention and should not be construed as being limitations on the scope or spirit of the instant invention. Example 1 Synthesis of (2S)-2-({6-chloro-3-[6-(4-chlorophenoxy)-2-propylpyridin-3-yl]-1,2-benzisoxazol-5-yl}oxy)propanoic acid (Compound I) [0025] Compound I is made by the multi-step process shown in Schemes 1 and 2 below. The process is described in detail in the description after the schemes. Compound I is (S)-14 in the schemes and description below. Synthesis of Hydroxybenzisoxazole Intermediate 10 [0026] Synthesis of Chiral Acid 14 [0027] Steps 1 and 2. Esterification and Aryl Ether Formation [0028] [0029] To a solution of 2,6-dichloronicotinic acid (1) (9.2 g, 0.10 mol) in MeOH (100 mL) was added 5.56 mL (0.10 mol) of concentrated H 2 SO 4 dropwise. An ˜15° C. temperature increase was observed. The resulting solution was heated at 60° C. for 8-14 hrs. [0030] The reaction mixture was allowed to cool to RT and then poured into a biphasic mixture containing IPAc (220 mL) and aq. K 2 CO 3 (20.7 g in 117.3 g water) at RT with stirring. The organic layer was separated, washed with sat. NaHCO 3 (80 mL), and then water (80 mL). The isolated IPAc solution was subjected to a solvent switch to DMF (80 mL) in vacuo. [0031] A solution of 4-chlorophenol (12.2 g, 0.095 mol) in 36.6 mL of DMF was added at room temperature to the above solution (19.6 g of ester 2, 0.095 mol), followed by addition of triethylamine (17.3 mL, 0.124 mol) at 20-22° C. over 15 min. Solid DABCO (1.6 g, 14.2 mmol) was added to the resulting solution in one portion. A temperature increase of ˜3° C. was observed. A water bath was used to maintain the reaction temperature. The reaction was stirred at 22-24° C. for 4-5 h while monitoring by LC until all of the 4-chlorophenol was consumed, resulting in a light slurry. AcOH (2.72 mL, 47.5 mmol) and IPA (57.5 mL) were added to the light slurry, followed by cold water (30 mL) to maintain the internal temperature at 20-25° C. When the water was added, a clear solution first formed, and then a slurry of product formed. After stirring at RT for 0.5 h, additional water (86 mL) was added over 0.5 h. After the slurry was stirred at RT for 1-2 h, it was filtered. The filter cake was washed with mixed solvents (60 mL of IPA:H 2 O=1:1). The isolated solid was dried in a vacuum-oven at 50° C. for 8 h to provide the product as white cotton-like solid. Step 3. Propylation [0032] [0033] To a solution of methyl 2-chloro-6-(4-chlorophenoxy)nicotinate (12.53 g, 42.03 mmol) and NiCl 2 dppe (111 mg, 0.5 mol %) in THF (63 mL) was added n-PrMgCl (2.0 M in diethyl ether, 22.5 mL, 45.0 mmol) over ½ h. The reaction was aged at 25° C. to 28° C. for 15 minutes. [0034] The reaction was then quenched with 10% citric acid solution (120 mL) and diluted with MTBE (120 mL). The mixture was stirred over 15 min. The organic layer was cut and was washed with 10% NaCl solution (120 mL). The organic layer (188 mL) was concentrated to 90 mL (½ volume), and 90 mL of MeOH was then added. The volume was again reduced to 90 mL by vacuum distillation. This was repeated 2 additional times to complete the solvent switch to MeOH. The final volume was about 90 mL. Step 4. Methyl Ester Hydrolysis [0035] [0036] To the solution of 4 from above was added 5N NaOH (13 mL, 65 mmol). The mixture was heated to 68° C. for 2.5 h. LC assay showed the reaction was complete. The reaction can also be run at 50° C., in which case it is typically complete in 4 h. Water (90 mL) was then added to the solution at 68° C., followed by 36 mL of 20% citric acid. The product crystallized from the solution. Water (90 mL) was then added. The slurry was stirred for 2 h and was then filtered. The white cake was washed with 150 mL of water/MeOH (2:1) and was dried in an oven at 62° C. overnight. Step 5. Friedel-Crafts Acylation [0037] [0038] To a 100 L round bottom vessel was charged nicotinic acid 5 (7200 g, 24.68 Mol), which was then dissolved in 17 L of trifluoroacetic anhydride (TFAA). 1,4-Dimethoxy-2-chlorobenzene (6337 mL, 44.42 Mol) was added, followed by slow addition of triflic acid (4426 mL, 2 equivalents), while maintaining the temperature at <40° C. A reflux condenser was attached, and the reaction was heated to 42° C. and stirred overnight. The reaction was assayed, showing a 70% conversion by mass of 5 to 7. [0039] An additional triflic acid charge (440 mL, 0.20 equivalents) was made, and a distillation setup was substituted for the reflux condenser. The batch was heated to 55° C., and ˜9 L of TFAA was distilled into an ice cooled 22 L RBF. The batch was aged at 55° C. for 4 hours. At this point the reaction had reached completion. [0040] The reaction was cooled to ambient temperature with an ice bath, and was then quenched into a 100 L extractor at 0° C. onto 30 L (6 molar equivalents) of 5 N KOH and 25 L (3.5 volumes) of toluene, maintaining the temperature at <50° C. for 1 hour. The 100 L flask was rinsed into the extractor with 2×2 L of toluene and 2×2 L of 5N KOH. The phases were separated at room temperature, and the organic phase was washed with 18 L of 1N HCl. [0041] The organic solution was transferred back into the rinsed 100 L vessel and was treated with Darco G-60 (3.6 kg, 50 wt %). The mixture of solution and carbon was heated at 35° C. for 30 min. The charcoal mixture was then filtered through a pad of solka floc, rinsed with 8 L of toluene and vacuum transferred through a 5 uM poly cap, into a visually clean 100 L round bottom flask, with a mark at the 16 L level. The 100 L flask was attached to a batch concentrator and distilled down to the 16 L mark at 35° C. At this point the batch was seeded with 10 g of seed crystals of 7 obtained from an earlier batch, and heptane addition began. After 20 L of heptane had been added the slurry grew thick. The batch was heated to 55° C., and an additional 4 L of heptane was added bringing the total batch volume to the 40 L mark. The slurry was aged at 55° C. for 15 minutes with rapid stirring. At this point a constant volume distillation with the addition of heptane was begun, and the batch temperature was cooled and then was maintained between 30 and 35° C. A total of 80 L of heptane (including the original 24 L) was added to the batch. The solvent composition was checked by 1 H NMR, and was found to contain 94 mole % heptane. [0042] The slurry was then heated to 65° C. and allowed to slowly cool to room temperature overnight. [0043] The slurry was filtered, and the flask was rinsed with 9 L of a mixture of 95% heptane/5% toluene. The cake was then slurry washed with 9 L of 95% heptane/5% toluene, and then 18 L heptane. The product 7 was dried on the frit under a stream of N 2 at ambient temperature. Step 6. Demethylation of 7 to 8 [0044] [0045] Into a visually clean 200 mL two-neck RBF was charged 11.1 g of solid 93.5 wt % dimethoxyketone 7 (25 mmol), 18.75 g sodium iodide (125 mmol), HBr (48% aqueous, 50 mL, 0.5 mol), and HOAc (50 mL, 5× vol). The slurry was heated to 100° C. (dial-in temp.) in 0.5 hours, and the internal temperature gradually stabilized at 95-95.5° C. [0046] The slurry turned dark brown within two hours after the reaction temperature reached 90° C. Further heating for one hour gradually generated bright yellow crystals, and the precipitate became thicker with time. The reaction was stirred at 95-95.5° C. (Internal T) for 24 hours. [0047] The batch was cooled to room temperature, filtered, and sequentially washed with 50 mL HOAc (displacement wash), 50 mL HOAc (slurry wash) and 5% MeOH in water (3×50 mL, slurry washes). The isolated product was dried at r.t. under vacuum over the weekend. [0048] The dry powder product was then suspended in 5% MeOH in water (100 mL) for 4 hours and filtered. The filter cake was washed with 50 mL of water and dried under vacuum to give the final product as the free base. Step 7. Oxime Formation and Isomerization [0049] [0050] To a 100 L, 4-neck round bottom flask, with mechanical stirrer, reflux condenser, thermocouple and nitrogen/vacuum line, was charged n-propanol (24 L), dihydroquinone ketone (7.598 kg, 89% purity, 6.762 assay kg, 12.38 mol), and boric acid (808 g, 13.07 mol). Hydroxylamine (2.3 L, 37.60 mol) was then poured into the flask. The reaction was heated to reflux (90-92° C.) for 60 minutes. [0051] The reaction was cooled to 30° C. and transferred into a 180-L extractor containing 35 L of water. 15 L of water and 50 L of MTBE were added to the extractor and the mixture was vigorously stirred and allowed to settle. The bottom aqueous layer was cut. The organic layer was washed with 50 L of 20 wt % NaCl (aq), and then with 18 L of 20 wt % NaCl (aq). [0052] The organic layer was agitated with 3 kg of sodium sulfate and 1 kg of DARCO G-60 and filtered through a bed of Solkaflok. The cake bed was rinsed with 15 L of MTBE. The filtrate was concentrated to approximately 20 L at 35-40° C., 20-25 in. Hg. n-Propanol (60 L) was fed and distilled at 35-40° C., 28-30 in. Hg, while maintaining a constant volume of 20 L. The final batch KF was 860 ppm water. [0053] The resulting solution was heated on a steam pot to 93-97° C. The reaction was monitored for isomerization conversion. After 6 hours, the batch was allowed to cool to ambient temperature. 200 mL of the batch was sampled for seed formation. To the stirring solution, 50 mL of water was added, and then 1 g of seed was added, and the batch was aged to form a seed bed. The remaining 250 mL of water was added to complete the crystallization. [0054] To the batch, 5 L of water was added, followed by the seed slurry. The mixture was aged, giving a thick slurry. The remaining 25 L of water was added over 1 hour. The slurry was heated to 50° C. and cooled to ambient temperature. [0055] The solid was isolated by filtration. The cake was washed with 2:1 water/n-propanol (8 L, 8 L, 12 L, 12 L), water (8 L), then hexanes (12 L, 8 L). The solid was dried on the filter under a nitrogen tent. The E-oxime was obtained as an orange solid. Step 8. Benzisoxazole Formation [0056] [0057] To a 100 L cylindrical vessel with cooling coils, thermocouple, and nitrogen/vacuum inlets, was charged THF (23 L) and the oxime (4.953 kg, 4.661 assay kg, 10.76 mol). The dark brown solution was cooled to −15° C. CDI (2.70 kg, 16.65 mol) was added in two portions over 10 minutes. The reaction was aged at −5-0° C. for 1 hour. [0058] The reaction was then warmed to 25° C. MeOH (1.3 L) was added, and the solution was aged for 1 hour. [0059] To the reaction, 35 L of MTBE, 20 L of water, and 2.5 L of 85% phosphoric acid were added with vigorous stirring. After settling, the bottom aqueous layer was cut. The organic layer was washed with water (20 L), 0.5 M Na 2 CO 3 (2×20 L), 1M H 3 PO 4 (20 L), then 10 wt % KH 2 PO 4 (4 L). [0060] The batch was stirred with 1 kg of DARCO G-60 for 1.5 hours. The mixture was filtered through Solkaflok and the bed was washed with 14 L of MTBE. [0061] The filtrate was fed into a 100 L round bottom flask equipped with mechanical stirrer, thermocouple, and nitrogen inlet, and was attached to a batch concentrator. The batch was fed and distilled at 35-40° C., 16-20 in. Hg, maintaining the batch volume at 20-25 L. EtOAc (40 L) was then fed and distilled at 35-40° C., 20-23 in. Hg at a constant volume of 15-20 L. [0062] To a 100 L cylindrical vessel with heating coils were charged EtOAc (20 L) and TsOH/H 2 O (2.304 kg, 12.11 mol), and the mixture was heated to 35-45° C. to dissolve. The acid solution was fed into the isoxazole batch with further distilling, maintaining a constant volume of 25 L. An additional 20 L of EtOAc was distilled to azeotropically dry the mixture. A slurry began to form, and it continued to thicken on addition and concentration. The final KF was 400 ppm water. The batch was heated to 60° C. and allowed to slowly cool to ambient temperature overnight. [0063] The solid product was isolated by filtration. The cake was washed with EtOAc (16 L), then with MeCN (24 L), and was dried on the filter under a nitrogen tent. The benzisoxazole tosylate was obtained as a pale yellow solid. Step 9A. Lactate Tosylate Formation [0064] [0065] To a 50 L RBF was added 1.50 kg R-methyl lactate, which was then dissolved in EtOAc (7.5 L) with 3.02 kg tosyl chloride. The batch was cooled with ice to 6° C. A mild endotherm was noted on mixing. [0066] DABCO (242 g) and triethylamine (3.01 L) were separately dissolved in the 7.5 L of EtOAc. The solution was charged to a 50 L vessel, maintaining the temperature below 25° C. The reaction was aged 2 h at room temperature. A mild to moderate delayed exotherm was seen. A white slurry formed during the addition. [0067] To a 50 L extractor 4 L of water and 3 L of EtOAc were added with stirring. Water (3.5 L) was added to the reaction vessel, and the biphasic solution was transferred to the extractor. The vessel was then rinsed with 4.5 L EtOAc. To the stirred extraction was added 7.5 L of 2 N HCl, bringing the total extraction volume to 40 L. The extraction was aged 10 min and phase separated. The organic was washed with 7.5 L of water and then 15 L of 4% NaHCO 3 (aq). The organic solution was then transferred to clean plastic carboys, and dried over Na 2 SO 4 (5 kg) in the carboys. [0068] The batch was then filtered through a 20 uM poly cap filter into a Buchi rotary evaporator, yielding the product as an oil containing residual ethyl acetate (3 wt %) and 700 PPM water. The batch was transferred to a container and was stored in a cold room until it was used. The product had an ee of 98.2%. Step 9. Methyl Lactate Attachment [0069] [0070] To a 100 L RBF was added benzisoxazole tosylate 10 (5.7 kg, 10 moles), then K 2 CO 3 powder (5.7 kg, 42 moles), and then 25 L DMSO. A slight exotherm was noted. The reaction was stirred for 10 min, and the mixture was degassed and placed under N 2 . The slurry was cooled to <30° C., and the lactate tosylate 12 (2.8 kg, 11 moles) was added. The mixture was stirred for 24 hrs until HPLC showed >98% conversion. To the reaction was added 20 L MTBE and 30 L cold water. The cold water was added to moderate the slight exotherm on quenching. The layers were agitated for 10 min. [0071] The mixture was transferred to a 180 L cyclindrical vessel, and an additional 30 L MTBE and 30 L cold water were added. The layers were cut and the aqueous layer was back extracted with 25 L MTBE. The combined organic layers were washed with 18 L 2% NaHCO 3 . The final organic layer was fed with concurrent distillation into a 100 L RBF and solvent switched to acetonitrile. The batch was kept at 25-30° C. to prevent crystallization. [0072] The batch volume was adjusted to 45 L with acetonitile, and 36 L water was added slowly (product crystallizes after 4 L water is added). After overnight aging, the batch was filtered, and the cake was washed with 10 L 1/1 MeCN/water. Solid methyl ester S-13 on the funnel was dried with suction under nitrogen flow for 4 days. Step 10. Hydrolysis and Final Crystallization [0073] In a 50 L cyclindrical vessel, the methyl ester S-13 (2.3 kg) was dissolved in 12.5 L MeCN and mixed with 10 L 1N NaOH. The solution was aged for 2-3 hrs at ambient temperature. Toluene (25 L) was added, followed by conc. HCl to bring the pH to 2-3 (0.85 L). The resulting layers were separated. The organic layer was washed with 15 L brine and dried with Na 2 SO 4 and 0.7 kg Ecorsorb C-933. The slurry was filtered and the cake was washed with 10 L toluene. In a 100 L RBF, the filtrate was batch concentrated to 15 L. [0074] The batch volume was then adjusted to 18 L (8 L toluene/kg product). The batch was heated to 50° C., and 56 L of methylcyclohexane was added at 50° C. The batch was seeded with crystals from earlier batches after 18 L of methylcyclohexane was added. The batch was cooled slowly to ambient temperature (about 10 min per degree) to yield crystalline product S-14. The batch became thick at around 39° C. The batch was cooled further to ambient temperature over 4-8 hrs. It was aged a total of 16 hrs. [0075] The batch was filtered, and the cake was washed with 10 L of 4:1 methylcyclohexane/toluene, then 2×10 L of methylcyclohexane. It was dried on the filter pot under vacuum and nitrogen flow overnight, and was then transferred to a vacuum oven and dried with nitrogen flow overnight. Crystalline Free Acid Anhydrate [0076] The crystals isolated using the method described above are the preferred anhydrous crystalline free acid crystals. The crystals are anhydrous. They have very low water solubility at native pH, are stable with respect to retaining their crystal form, are chemically stable, and are non-hygroscopic. For example, they gain about 0.2 wt % when placed in an environment with up to 95% RH. Their melting point is 113-114° C. They have a small needle morphology and a high surface area without milling or grinding. They exhibit good bioavailability in laboratory studies in dogs and rats. The preferred crystalline anhydrate is obtained on crystallization from MTBE/hexanes or toluene/methylcyclohexane. Crystallization from toluene/methylcyclohexane is used in the synthetic procedure described above. Crystalline Benzenesulfonate Salt [0077] The benzenesulfonate salt of the compound having Formula I as described herein is crystalline and non-hygroscopic. The benzenesulfonate salt is chemically stable, remaining unchanged after 8 months at 40° C. and 75% RH. The benzenesulfonate salt has properties that make it suitable in pharmaceutical formulations. The salt has been made by the following procedure. [0078] A solution of benzenesulfonic acid (1.58 g, 10 mmol) in 10 ml acetonitrile was added to a solution of Compound I (4.87 g, 10 mmol) in 50 ml acetonitrile at 50° C. The reaction mixture was seeded at 40° C. with crystals of the Compound I benzenesulfonate salt from earlier batches, yielding a crystalline product. The same crystalline product can also be obtained without seeds if none are available. [0079] The mixture was cooled to room temperature and then was stirred for 2.5 hours. It was cooled to 0-5° C. and stirred for an additional 30 min. The solid was collected by filtration, and the cake was washed with 10 ml acetonitrile. The solid was dried on the funnel with suction, yielding 6.4 g (99% yield). Crystalline Anhydrous Tosylate Salt [0080] A toluenesulfonate (tosylate) salt of Compound I has also been prepared. The tosylate salt also can be prepared as a crystalline anhydrous material. The crystalline anhydrous tosylate salt of Compound I was prepared by the following method from the methyl ester of Compound I. MeCN (110 kg) was charged to a reactor. The methyl ester of Compound I (e.g. from step 9 of Example 1; 29.9 kg; 59.6 moles) was charged to the reactor, followed by a MeOH flush of the charge valve. 135 kg of 1.0N NaOH (˜131 moles) was added, followed by a water flush at 15-25° C. The solution was aged for 2-3 hours at 15-25° C. and then assayed for completion of the reaction. [0081] Concentrated 5N HCl (26.7 kg) was added using a pump to adjust the pH to 2-3. The solution was extracted with 295 kg ethyl acetate. The organic layer was separated from the aqueous layer and washed with 215 kg of 18% brine solution. [0082] The batch was filtered via a 0.6 micron filter and concentrated to 200-220 L at <40° C. and reduced pressure. The solvent was switched at constant volume to EtOAc at <40° C. and reduced pressure (˜125 to 252 mmHg). The water concentration by Karl Fischer titration was 72.3 μg/ml, the product concentration was 135.5 g/L, and the acetonitrile content was 0.36 v/v %. The batch was collected in drums. [0083] A solution of p-toluenesulfonic acid monohydrate (12 kgs; 62 moles) in ethyl acetate (135 kgs) was prepared and was also collected in drums. [0084] A charge of 60 kg EtOAc was added to the crystallizer through a 0.6 micron filter. A seed slurry (about 12.9 kg containing about 1 kg of media-milled tosylate seed in about 10 L ethyl acetate) was added to the reactor followed by about 10 kg of a pre-filtered EtOAc wash. The seed slurry was recycled from the bottom of the reactor through the outlet and back in through the inlet. Then, the batch of Compound I in EtOAc and the solution of p-toluenesulfonic acid (p-TSA) in EtOAc solution were charged simultaneously into the reactor over a period of about 8 hours. The charge rates for the concentrated batch and p-TSA/EtOAc solution were 0.3 kg/L and 0.4 kg/L respectively. The temperature was maintained at 15 to 25° C. After crystallization the batch was aged at 15 to 25° C. for 2 hours. [0085] Seeds for the crystallization step above are saved from earlier batches of Compound I tosylate. The same crystalline product can also be obtained without seed crystals if none are available. [0086] The batch was filtered and the cake was washed with a total of 240 kg ethyl acetate. The batch was dried under vacuum at 40° C., yielding about 35.8 kg of the desired tosylate salt, for a yield of 90.5% for the salt preparation. The dried batch was delumped prior to further use. Dosage Form [0087] The crystalline free acid anhydrate and the crystalline anhydrous benzenesulfonate salt of Compound I are formulated as either dry filled capsules or compressed tablets in doses that generally will range from 1 mg to 25 mg of API as the free acid (non-salt). Typically, the doses will be in the range of 2-10 mg. A typical capsule or tablet formulation contains the crystalline free acid anhydrate or the crystalline anhydrous benzenesulfonate salt, microcrystalline cellulose (Avicel), lactose monohydrate, croscarmellose sodium, sodium lauryl sulfate, and magnesium stearate. The capsule formulations are transferred to a capsule made of gelatin, titanium dioxide, and ferric oxide. Tablet formulations are coated with a functional film coat containing lactose, hypromellose, triacetin, titanium dioxide, and ferric oxide. The capsule shell and tablet film coating are opaque to protect the active compound from light. [0088] The formulations are manufactured by first blending the excipients, then compressing the mixture into ribbons by roller compaction, and then milling the ribbons into granules. The granules are then lubricated and either filled into capsules or compressed into tablets. If tablets are selected, a film coat is applied to the compressed tablets. [0089] Exemplary fill formulations that provide a 5 mg or 10 mg dose of Compound I (free acid) in a standard gelatin capsule are shown below. The components are combined, compressed and milled as described above, and then the amount of milled formulation that contains the 5 mg or 10 mg dose of Compound I is transferred to each capsule. [0000] Components 5 mg Dose 10 mg Dose Compound I (free acid weight) 5 mg 10 mg Microcrystalline cellulose (Avicel) 44.5 mg 42 mg Lactose monohydrate (Diluent) 44.5 mg 42 mg Croscarmellose sodium (Disintegrant) 3 mg 3 mg Sodium lauryl sulfate (surfactant) 2 mg 2 mg Magnesium stearate (lubricant) 1 mg 1 mg Characterization of the Crystalline Free Acid Anhydrate [0090] X-ray powder diffraction studies are widely used to characterize molecular structures, crystallinity, and polymorphism. The X-ray powder diffraction patterns of the crystalline anhydrous free acid form of Compound I were generated on a Philips Analytical X'Pert PRO X-ray Diffraction System with PW3040/60 console. A PW3373/00 ceramic Cu LEF X-ray tube K-Alpha radiation was used as the source. Silicon powder (NIST reference standard 640 C) was mixed in the sample and was used as a reference for d-spacing assignment. [0091] FIG. 1 shows the X-ray diffraction pattern for the crystalline free acid anhydrate. The crystalline free acid anhydrate exhibited characteristic reflections corresponding to d-spacings of 17.13, 5.11, and 4.82 angstroms. The crystalline free acid anhydrate was further characterized by reflections corresponding to d-spacings of 11.63, 7.88 and 7.42 angstroms. The crystalline free acid anhydrate was even further characterized by reflections corresponding to d-spacings of 10.27, 4.64 and 4.01 angstroms. [0092] In addition to the X-ray powder diffraction patterns described above, the crystalline free acid anhydrate of Compound I was further characterized by solid-state carbon-13 nuclear magnetic resonance (NMR) spectra. The solid-state carbon-13 NMR spectra were obtained on a Bruker DSX 500WB NMR system using a Bruker 4 mm H/X/Y CPMAS probe. The carbon-13 NMR spectra utilized proton/carbon-13 cross-polarization magic-angle spinning with variable-amplitude cross polarization, total sideband suppression, and SPINAL decoupling at 100 kHz. The samples were spun at 10.0 kHz, and a total of 10 k scans were collected with a recycle delay of 5 seconds. A line broadening of 10 Hz was applied to the spectra before FT was performed. Chemical shifts are reported on the TMS scale using the carbonyl carbon of glycine (176.03 p.p.m.) as a secondary reference. [0093] FIG. 2 shows the solid-state carbon-13 CPMAS NMR spectrum for the crystalline free acid anhydrate. The crystalline free acid anhydrate exhibited characteristic signals with chemical shift values of 118.7, 17.8, 149.3, and 76.4 p.p.m. Further characteristic of the crystalline free acid anhydrate are the signals with chemical shift values of 115.4, 19.6, 162.7, and 76.0 p.p.m. The crystalline free acid anhydrate is even further characterized by signals with chemical shift values of 13.6, 113.3, 173.1, and 38.1 p.p.m. [0094] DSC data for the crystalline free acid anhydrate were acquired using TA Instruments DSC 2910 or equivalent instrumentation. Between 1 and 6 mg sample was weighed into an open pan. This pan was then placed at the sample position in the calorimeter cell. An empty pan was placed at the reference position. The calorimeter cell was closed and a flow of nitrogen was passed through the cell. The heating program was set to heat the sample at a heating rate of 10° C./min to a temperature of approximately 200° C. The heating program was started. When the run was completed, the data were analyzed using the DSC analysis program contained in the system software. The melting endotherm was integrated between baseline temperature points that are above and below the temperature range over which the endotherm was observed. The data reported are the onset temperature, peak temperature and enthalpy. [0095] FIG. 3 shows the differential calorimetry scan for the crystalline free acid anhydrate. The crystalline free acid anhydrate exhibited an endotherm due to melting and decomposition with an onset temperature of 109.4° C., a peak temperature of 113.6° C., and an enthalpy change of 56.8 J/g. [0096] Thermogravimetric (TG) data were acquired using a Perkin Elmer model TGA 7 or equivalent instrumentation. Experiments were performed under a flow of nitrogen and using a heating rate of 10° C./min to a maximum temperature of approximately 250° C. After automatically taring the balance, 1 to 10 mg of sample was added to the platinum pan, the furnace was raised, and the heating program started. Weight/temperature data were collected automatically by the instrument. Analysis of the results was carried out by selecting the Delta Y function within the instrument software and choosing the temperatures between which the weight loss was to be calculated. Weight losses are reported up to the onset of decomposition/evaporation. [0097] FIG. 4 shows a characteristic thermogravimetric analysis (TGA) curve for the crystalline free acid anhydrate. TGA indicated a weight loss less than 0.1% from ambient temperature to about 109° C. Characterization of the Crystalline Anhydrous Benzenesulfonate Salt [0098] The X-ray powder diffraction patterns of the crystalline anhydrous benzenesulfonate salt were generated on a Philips Analytical X'Pert PRO X-ray Diffraction System with PW3040/60 console. A PW3373/00 ceramic Cu LEF X-ray tube K-Alpha radiation was used as the source. [0099] FIG. 5 shows the X-ray diffraction pattern of the crystalline anhydrous benzenesulfonate salt. [0100] The crystalline anhydrous benzenesulfonate salt exhibited characteristic reflections corresponding to d-spacings of 13.36, 8.38, and 6.86 angstroms. The crystalline anhydrous benzenesulfonate salt was further characterized by reflections corresponding to d-spacings of 9.85, 6.23 and 5.66 angstroms. The crystalline anhydrous benzenesulfonate salt was even further characterized by reflections corresponding to d-spacings of 7.23, 6.04 and 5.28 angstroms. [0101] DSC data of the crystalline anhydrous benzenesulfonate salt were acquired using TA Instruments DSC 2910 or equivalent instrumentation. Between 1 and 5 mg of sample was weighed into an open pan. [0102] The lid was placed lightly to cover the sample. The covered pan was then placed at the sample position in the calorimeter cell. An empty pan with lid was placed at the reference position. The calorimeter cell was closed and a flow of nitrogen was passed through the cell. The beating program was set to heat the sample at a heating rate of 10° C./min to a temperature of approximately 250° C. The heating program was then started. When the run was completed, the data were analyzed using the DSC analysis program contained in the system software. The melting endotherm was integrated between baseline temperature points that are above and below the temperature range over which the endotherm was observed. The data reported are the onset temperature, peak temperature and enthalpy. [0103] FIG. 6 shows the differential calorimetry scan for the crystalline anhydrous benzenesulfonate salt. The crystalline anhydrous benzenesulfonate salt exhibited a single endotherm due to melting with an onset temperature of 206.6° C., a peak temperature of 208.1° C., and an enthalpy change of 95.4 J/g.

A novel crystalline anhydrate of the free acid and a crystalline anhydrous besylate salt of a selective PPAR gamma partial agonist which has a fused bicyclic aromatic group attached to an oxypropanoic acid moiety are stable and non-hygroscopic. The compounds are suitable for preparing pharmaceutical formulations for the treatment of type 2 diabetes, hyperglycemia, obesity, and dyslipidemia.

BACKGROUND OF THE INVENTION 1. Field of the Invention Graft copolymers of starch-containing materials (SCM) with unsaturated organic monomers are well known in the art and can be tailored for use in many diverse applications. For example, starch graft copolymers having the appropriate ionic functionalities have been extensively used in paper and mineral separation industries as pigment retention aids capable of adjunctly serving as internal sizing agents or as flocculants. A discussion of prior art uses of such water-soluble polymers is found in "Recent Advances in Ion-Containing Polymers," M. F. Hoover and G. B. Butler, J. Poly. Sci. Symp. No. 45: 32-34 (1974). However, the future of SCM graft copolymers as an alternative to other functional agents may well hinge upon the introduction of a simple and economical procedure to prepare them. This invention relates to an improved process for the graft polymerization of acrylic monomers onto SCM. 2. Description of the Prior Art Starch graft polymerizations are conventionally promoted by initiation of free radicals on the starch backbone by (1) chemical treatment, (2) physical treatment, or (3) irradiation. Reviews of these prior art procedures are found in Block and Graft Copolymerization, Vol. 1, Chapters 1 and 2, Ed. R. J. Ceresa, John Wiley & Sons, Inc., New York, N.Y. (1973) and "Starch, Graft Copolymers," Encyclopedia of Polymer Science and Technology, Supplement No. 2, George F. Fanta and E. B. Bagley, pp. 665-699, John Wiley & Sons, Inc., New York, N.Y. (1977). Chemical procedures include treatment with (a) inorganic ions, e.g., ceric, chromic, and cobaltic; (b) redox systems incorporating a reducing agent and an oxidizing agent, such as ferrous ion-peroxide; and (c) organic materials, e.g., azo compounds, or solvents such as xylene, etc. All previously known free radical initiations by chemical methods have required a liquid medium which comprises either an aqueous solvent or a combination of aqueous and organic solvents. Consequently, recovery of the polymerization product involves isolation, washing, and drying steps. These steps are often the most difficult and expensive in preparation of SCM graft copolymers because high viscosities develop as the reaction progresses. Also the spent reaction medium has to be recovered and processed in order to avoid contamination of the environment. This has lead to the investigation of several dry methods for preparing SCM graft copolymers. Physical procedures for initiating free radicals which can be conducted in the dry state include ball milling [J. Poly. Sci. 62(174): S123-S125 (1962), R. L. Whistler and J. L. Goatley], mechanical mastication [Staerke 16(9): 279-285 (1964), B. H. Thewlis], and heat and mastication as by an extruder or similar device ["Water-Soluble Polymers,"Polymer Science and Technology, Vol. 2, G. F. Fanta et al., pp. 275-290, Plenum Publishing Corp., New York, N.Y. (1973)]. The resulting products from these procedures are actually block polymers, and they tend to be highly degraded, rubbery to hard, and both chemically and physically brittle. More useful grafted starch products, although degraded, have been prepared by a dry irradiation technique. Cobalt 60 has been used to initiate the free radicals as described in "Water-Soluble Polymers," supra, and U.S. Pat. No. 3,976,552. Other types of conventional irradiation include electron beam, ultraviolet, and X-rays. However, because of the advance technology required, expense and problems of scaleup, and hazardous nature of the reaction, irradiation techniques for initiation of free radicals in dry grafting of unsaturated organic monomers onto SCM has remained only a laboratory curiosity. These above factors all reduce the commercial desirability and practicability of the prior art methods of producing SCM acrylic graft copolymers. SUMMARY OF THE INVENTION I have now unexpectedly discovered that acrylic monomers can be grafted onto SCM in the dry state using a chemical, free radical initiation which does not require a liquid medium. Even more surprising is the discovery that the chemical initiator, consisting essentially of a peroxide, is able to promote free radicals on the starch backbone in a dry state reaction without the need of a reducing agent in a defined redox system. The acrylic monomers and peroxides are added to the SCM as powders or sprays and when the reactants are thoroughly blended, the reaction proceeds without mixing. In accordance with this discovery, it is an object of the invention to prepare graft copolymers of starch-containing materials by means of a chemically initiated dry state reaction. It is also an object of the invention to provide a simple and economical procedure for preparing starch-based graft copolymers which are characterized by either cationic, anionic, or nonionic functionalities. It is a further object of the invention to prepare pigment retention aids and dry strength agents for use in the manufacture of paper which are superior to similar products prepared by dry irradiation techniques. Other objects and advantages of this invention will become readily apparent from the ensuing description. DETAILED DESCRIPTION OF THE INVENTION Starch-Containing Materials (SCM). The starting substrate useful in these reactions includes starches and flours of cereal grains such as corn, wheat, sorghum, rice, etc. and of root crops such as potato, tapioca, etc. The starches or flours may be unmodified or modified by procedures by which they are dextrinized, hydrolyzed, oxidized, or derivatized as long as they retain sites for subsequent reaction. Starch fractions, namely amylose and amylopectin, may also be employed. These SCM preferably contain their normal moisture content of 10 to 15%, though moisture as high as about 25% can be employed if it is not raised much beyond this level by addition of the reagent. Reagents The acrylic monomers which can be grafted onto the above-mentioned SCM in accordance with the invention are characterized by the following structural formulas: ##STR1## wherein R 1 =--H, or is from the group of C 1 -C 6 straight, branched, or cyclic alkyl radicals; ##STR2## with the proviso that if R 2 is --H, then the functional group A is eliminated; wherein each R 3 is independently selected from the group of --H, and C 1 -C 6 straight or branched alkyl radicals, and wherein two R 3 substituents may be joined together to form a cyclic structure; and wherein m=0, 1 and n=1-6; Of particular interest, without limitation thereto, are monomers in which A and B are as follows: A=a cationic group selected from: ##STR3## wherein R 3 is as defined above, and may be the same as or different from the R 3 on the R 2 group; and wherein X=Cl - , Br - , or I - ; and X'=X, R 3 X, or R 3 SO 4 - ; or an anionic group selected from: ##STR4## wherein R 4 is --H, alkali or alkali earth metal, or is from the group of C 1 -C 6 straight, branched, or cyclic alkyl radicals; or a nonionic group selected from: ##STR5## wherein R 1 , R 3 , m, and n are as defined above and may be the same as or different from similar designations in the structure; and ##STR6## wherein R 3 and X are as defined above; and wherein R 5 =--CH 3 , ##STR7## wherein r=0-7. Of course, it is understood that mixtures of the monomers could also be employed. Expressed in terms of weight percent, the amount of reagent for use in the reaction should be in the range of about 1-150% based on the dry weight of the SCM starting material. However, 3 to 18 weight percent is preferred. Catalysts Peroxide catalysts which can be incorporated in the reaction mixture to initiate free radicals include hydrogen peroxide; organic peroxides such as benzoyl, and acetyl; and inorganic peroxides of alkali and alkali earth metals such as sodium and calcium. In accordance with the invention, these peroxides constitute non-redox catalysis systems. Such a system is defined herein as one which excludes a discrete reducing agent; that is, an oxidizable agent present in the reaction mixture having the primary function of reducing the peroxide. For the non-flour SCM, the amount of peroxide needed to effect catalysis expressed as weight percent of O 2 based upon the dry weight of the SCM will be in the range of about 0.01 to about 0.5%, with the preferred range being 0.02-0.2%. It should be noted that the peroxides also serve as bleaching agents for the flours in the reaction. For example, a white corn flour product may be produced from a yellow corn flour starting material. Therefore, because of the color pigment (xanthophyll) and protein content of the flours about twice the amount of peroxide is needed as compared with a similar starch grafting reaction. Also, because the content of protein and pigment in agricultural vary from growing season to growing season, this amount of peroxide might require some adjustment to achieve the desired results for flours. Reaction Conditions When admixed with the SCM, the reagent and peroxide additives may be in either a dry powdery state or else dissolved or dispersed in a liquid vehicle such as water. The order of addition is not critical. If a vehicle is employed, its level should be limited to the extent that the reaction mixture as a whole remains in the form of a powder and its total moisture content is not raised beyond about 25% whereby the SCM would become sticky. A reaction mixture so characterized is defined herein as being in the dry state. Suitable reaction vessels include mixers of the conventional types used in industry, such as sigma blades, ribbon blades, pin blades, etc. I have found that continued mixing is optional once the additives have been thoroughly impregnated into the SCM. This may vary from a few minutes to several hours depending on the efficiency of equipment and the scale of run. The point of thorough impregnation would be readily determinable by a person or ordinary skill in the art. The reaction is carried out on the acid side at about pH 2 to 6.5. Since most SCM are inherently characterized by a pH in the range of 5-7, adjustment is usually unnecessary. The reaction temperatures are normally held within the range of about 25°-100° C. for inversely related periods of time ranging from 3 weeks to 1-2 hours, in which time the reaction is completed. The reaction is finished in 4 hours at 70° C. and 8 hours at 60° C. Properties of Products SCM graft copolymers of ionic monomers produced by this method are generally characterized by their change. Quality products are determined by the positive (cationic) or negative (anionic) charge possessed by samples that maintain them over a pH range of 3 to 10, whereas starting materials or samples that have not completely reacted with the reagent do not maintain the same ionic charge over the pH range. For those SCM products possessing a positive charge, cationic efficiencies are also helpful in determining their quality and effectiveness in end-use applications such as pigment retention aids in paper pulp. If reacted to completion within the limits of the time and temperature parameters set forth above, cationic efficiencies on the order of 99-100% are normally obtained. The SCM acrylic acids and esters (Formula 1), amides (Formula 2), and aminimides (Formula 3) produced by this process can be used in whatever application that similar products are conventionally employed as known in the art, and over a broad range of acid and alkaline pH's from about 3-10. For example, in the manufacture of paper, the cationic derivatives are useful pigment retention aids and strengthening agents when added to the wet pulp in concentration on the order of about 0.1 to 2% based on the dry weight of the pulp. These products may also be used in conjunction with other additives which are compatible with their ionic functionality as easily determined by a person in the art. Test Methods For purposes of evaluating the SCM products prepared in the examples below, the following tests procedures were employed. 1. pH was measured with a Beckman meter on a 1-2% aqueous pasted sample. The pasting procedures were water bath or steam jet cooking as described in Die Starke 28(5): 174 (1976). 2. Streaming current values were measured with a streaming current detector manufactured by Water Associates, Inc., Framingham, Mass. The instrument determines the magnitude of the cationic (positive) or anionic (negative) charge possessed by a sample. A 0.5% pasted sample (water bath cooked) was tested for these values (SCV) at various pH levels. The pH value was obtained by adjusting the paste solution with either 1 N HCl or NaOH solutions. 3. Cationic efficiency was determined by a modified procedure of Mehltretter et al., Tappi 46(8): 506 (1963) as reported in Tappi 52(1): 82 (1969). Briefly, percent efficiency was obtained photometrically when a 0.5% paste (cooked by water bath) sample is tested for the retention on dilute cellulosic pulp fibers of "Halopont Blue" (an intensely blue organic pigment). 4. Handsheets were made and tested by procedures cited in Tappi 52(1): 82 (1969). Controls containing no product additive as well as those containing 2% of product additive based on oven-dried unbleached pulp were prepared. The percent increase in sheet properties due to the additive were reported. Products tested were 1% pasted samples prepared by steam jet cooking. 5. Nitrogen determinations (dry basis) on samples were obtained by Kjeldahl analyses and moisture content on samples by drying them to constant weight at 100° C. in vacuo over phosphorous pentoxide. 6. To determine the amount of monomer grafted to polymer (SCM+monomer) and homopolymer (monomer+monomer) in the products, samples were washed by the following method: (1) distilled water; (2) 60:40 mixture by volume of ethanol:distilled water; (3) 100% ethanol. Ten grams of sample were stirred in a centrifugal bottle for 1/2 hour with 100 ml. of (1) at 25° C. The slurry was then centrifuged for 15 minutes and the supernatant poured off. This was repeated once. The residue was stirred with 100 ml. of (2), stirred with 100 ml. of (3), centrifuged, filtered, and washed with (3). The washed sample was oven dried overnight at 50° C., ground up, and analyzed. The following examples are intended only to further illustrate the invention and are not intended to limit the scope of the invention which is defined by the claims. EXAMPLE 1 One hundred and twenty-five grams (dry basis) of commercially obtained wheat starch having a 10% moisture content and 0.08% Kjeldahl nitrogen were placed in a laboratory model sigma blade kneading machine equipped with a removable transparent plastic cover, reagent admitting means, and a valved jacket for confining steam or coolant. The reagent was "Sipomer Q-6" (solution, Table I) of which 20 g. (75%, 12 weight percent monomer based on dry weight of starch) was sprayed onto the starch in 10 minutes while mixing. Mixing was continued 1/4 hour before flaking in powdered "Novadelox" 0.74 g. (32% benzoyl peroxide, 0.024% O 2 based on dry weight of starch). Mixing was continued another 1/4 hour, stopped, and samples were removed, bottled, and stored at 60° C. for 6 hours (A), 8 hours (B), and 10 hours (C). Table II gives results of analyses at various reaction time periods. A superior operative final cationic product is indicated by the presence of significantly increased retention efficiency of "Halopont" pigment dye (cationic efficiency) by the pulp and in the magnitude and positive (cationic) charge (SCV) over pH range of 3 to 10 as compared to those found for wheat starch (starting material) and sample 1A. EXAMPLE 2 Example 1 was repeated except a temperature of 70° C. was used for sample (A) 2 hours, (B) 4 hours, (C) 6 hours. Results are given in Table III. EXAMPLE 3 Example 1 was repeated except for the following: The reagent was "Sipomer Q-1" (solid, Table I) of which 16.7 g. (90%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). Sample (A) was reacted at 25° C., (B) at 70° C., and (C) at 100° C. Samples were analyzed at various time periods to monitor the reaction and final results are present in Table IV. Further evaluation of products A and C is given in Example 14. TABLE I__________________________________________________________________________ % Mono- mer Phys- Reagent Mole in ical TradeAcrylic monomer Structure wt. reagent state Charge Company name__________________________________________________________________________2-hydroxy-3-methacryloyl- oxypropyltrimethylammonium chloride ##STR8## 237.6 90 solid cat- ionic Alcolac Chemical Corp. Sipomer Q-12-methacryloyloxyethyl- trimethylammonium methyl sulfate ##STR9## 283.4 40 liquid cat- ionic Alcolac Chemical Corp. Sipomer Q-52-methyacryloyloxyethyl- trimethylammonium chloride ##STR10## 207.6 75 liquid cat- ionic Alcolac Chemical Corp. Sipomer Q-6methacrylamidopropyl- trimethylammonium chloride ##STR11## 220.8 50 liquid cat- ionic Jefferson Chemical Co. MAPTAC2-acrylamido-2-methyl- propanesulfonic acid ##STR12## 207.0 100 solid an- ionic Lubrizol Corp. AMPS3-acrylamido-3-methyl butyltrimethylammonium chloride ##STR13## 234.8 100 solid cat- ionic Lubrizol Corp. AMBTAC__________________________________________________________________________ TABLE II______________________________________Reaction Resultsconditions SCV % Time, Temp., pH pH pH CationicExample hours °C. 3 6 10 efficiency______________________________________1A 6 60 +2.8 +2.8 -0.1 471B 8 60 +11.5 +5.6 +4.9 1001C 10 60 +6.3 +8.9 +3.3 100wheat -- -- +2.0 -16.0 -18.0 37starch______________________________________ Products A, B, and C have 13% moisture and 0.77% nitrogen; pH of pastes was 4.3. TABLE III______________________________________Reaction Resultsconditions SCV % Time, Temp., pH pH pH CationicExample hours °C. 3 6 10 efficiency______________________________________2A 2 70 +3.1 +2.9 -0.7 472B 4 70 +9.2 +7.4 +4.3 992C 6 70 +11.0 +12.3 +5.9 99______________________________________ Products A, B, and C have 14% moisture, and 0.78% nitrogen; pH of pastes was 4.3. TABLE IV______________________________________Reaction Resultsconditions SCV % Temp., pH pH pH CationicExample Time °C. 3 6 10 efficiency______________________________________3A 21 days 25 +8.0 +12.7 +5.0 1003B 4 hours 70 +14.5 +18.0 +5.6 1003C 2 hours 100 +16.3 +12.1 +4.0 100______________________________________ Products A, B, and C have 14% moisture, and 0.70% nitrogen; pH of pastes was 4.7. EXAMPLE 4 Example 1 was repeated except for the following: The reagent was "Sipomer Q-5" (solution, Table I) of which 47 g. (40%, 15 weight percent monomer based on dry weight of starch was sprayed onto the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). The sample was reacted for 2 hours at 100° C. The final product had 23% moisture, 0.70% nitrogen, pH 4, SCV at pH 3+10.8, pH 6+6.9, pH 10+4.8, and cationic efficiency 100%. Further evaluation of this product is given in Example 14. EXAMPLE 5 Example 1 was repeated except for the following: The reagent was "MAPTAC" (solution, Table I) of which 30 g. (50%, 12 weight percent monomer based on dry weight of starch) was sprayed onto the starch. Hydrogen peroxide was used instead of benzoyl peroxide and 0.88 g. (30% peroxide, 0.19% O 2 based on dry weight of starch) was sprayed onto the starch. The sample was reacted for 2 hours at 100° C. The final product had 19% moisture, 1.42% nitrogen, pH 4.5, SCV at pH 3+9.4, pH 6+5.1, pH 10+4.6, and cationic efficiency 99%. Further evaluation of this product is given in Example 14. EXAMPLE 6 Example 1 was repeated except for the following: The reagent was "AMBTAC" (solid, Table I) of which 15 g. (100%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). The sample was reacted 2 hours at 100° C. The final product had 12% moisture, 1.27% nitrogen, pH 4.2, SCV at pH 3+8.4, pH 6+10, pH 10+3.4, and cationic efficiency 99%. EXAMPLE 7 Example 1 was repeated except for the following: The reagent was "AMPS" (solid, Table I) of which 15 g. (100%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). The sample was reacted 2 hours at 100° C. The final product had 14% moisture, 0.88% nitrogen, pH 3.4, and SCV at pH 3 -14, pH 6 -19, pH 10 -21. The excellency of this anionic product is shown by the magnitude and negativity of its charge over a pH range of 3 to 10. EXAMPLE 8 Example 1 was repeated except for the following: The reagent was "Sipomer Q-1" (solid, Table I). "Novadelox" was increased to 5.9 g. (32% benzoyl peroxide, 0.2% O 2 based on dry weight of starch). In sample (A) 18.9 g. (90%, 13.6 weight percent monomer based on dry weight of starch) of reagent was used, (B) 14.4 g. (10.4 weight percent), (C) 8.9 g. (6.4 weight percent), and (D) 4.4 g. (3.2 weight percent). The samples were reacted 2 hours at 100° C. To determine the amount of monomer grafted to the SCM, the homopolymer was washed out of the products by test procedure 6, analyzing both product and washed product. As noted by the results given in Table V, a relatively large proportion of the monomer is grafted onto the SCM. Further evaluation of these products is given in Example 14. EXAMPLE 9 For purposes of comparing the process of the invention to that of the prior art, Example 1 was repeated except for the following: The starch was 100 g. (dry basis) and the reagent was "Sipomer Q-5" (solution, Table I) of which 15.2 g. (40%, 6 weight percent monomer based on dry weight of starch) was sprayed onto the starch. Portions of the sample were bottled and irradiated with a Cobalt 60 source at three levels. Sample (A) 0.1 Mrad, (B) 1.0 Mrad, (C) 3.0 Mrad. The results are presented in Table VI. EXAMPLE 10 Comparative Example 9 was repeated except for the following: The starch was 125 g. (dry basis) and the reagent was "Sipomer Q-1" (solid, Table I) of which 12.6 g. (90%, 9 weight percent monomer based on dry weight of starch) was flaked into the starch. The results are presented in Table VI. TABLE V______________________________________ % MonomerProduct, % Washed product, % graftedExample Moisture Nitrogen Moisture Nitrogen to SCM*______________________________________8A 13 0.69 7 0.49 718B 12 0.54 8 0.36 678C 12 0.40 7 0.29 738D 13 0.23 7 0.15 65______________________________________ ##STR14## EXAMPLE 11 Comparative Example 9 was repeated except for the following: The starch was 125 g. (dry basis) and the reagent was "MAPTAC" (solution, Table I) of which 7.6 g. (50%, 3 weight percent monomer based on dry weight of starch) was sprayed onto the starch. The results are presented in Table VI. The cationic products prepared by the irradiation techniques of Examples 9-11 were inferior to the cationic products in the preceding examples of this invention as shown by their SCV and cationic efficiency values. EXAMPLE 12 For comparative purposes, Example 5 was substantially repeated without the peroxide catalyst. The reagent was "MAPTAC" (solution, Table I) of which 30 g. (50%, 12 weight percent based on dry weight of starch) was sprayed onto the starch. The mixture was held for 4 hours at 100° C. The moisture content, nitrogen content, paste pH, SCV, and cationic efficiency of the product were determined. The product was then washed by test procedure 6, and the moisture and nitrogen contents were again determined. The nitrogen content was less than in the wheat starch starting material. The results are shown in Table VII. EXAMPLE 13 For comparative purposes, Example 6 was substantially repeated without the peroxide catalyst. The reagent was "AMBTAC" (solid, Table I) of which 15 g. (100%, 12 weight percent monomer based on dry weight of starch) was flaked into the starch. The mixture was held for 4 hours at 100° C. The moisture content, nitrogen content, paste pH, SCV, and cationic efficiency of the product were determined. The product was then washed by test procedure 6, and the moisture and nitrogen contents were again determined. The nitrogen content was less than in the wheat starch starting material. The results are shown in Table VII. TABLE VI______________________________________ Results % Cat- Analysis ionicEx- % pH SCV effi-am- Co.sup.60 Mois- % of pH pH pH cien-ple Mrad ture N paste 3 6 10 cy______________________________________9A 0.1 17 0.30 4.8 +2.4 +2.4 -9.3 429B 1.0 17 0.30 4.8 +16.0 +9.8 +2.1 609C 3.0 17 0.30 4.8 +6.9 +11.0 +1.1 6410 3.0 14 0.69 5.6 +10.8 +15.9 +1.1 5811 3.0 16 0.38 5.0 +6.1 +8.8 +0.8 55______________________________________ TABLE VII__________________________________________________________________________ % Monomer SCV %Product, % Washed product, % grafted pH of pH pH pH CationicExampleMoisture Nitrogen Moisture Nitrogen to SCM* paste 3 6 10 efficiency__________________________________________________________________________12 18 1.38 8 0.04 <3 6.0 +4.3 -0.7 -2.4 3413 13 1.41 7 0.02 <2 6.0 +4.9 +0.5 -0.7 34__________________________________________________________________________ ##STR15## The SCV and cationic efficiency values and the nitrogen result on the washed product of Examples 12 and 13 indicated that the reaction did not take place in the absence of peroxide. EXAMPLE 14 Unbleached handsheets were prepared and tested as described above in test 4. Results are given in Table VIII. Products of this invention were far superior in increasing burst (three times) and tensile (six times) strengths in unbleached handsheets above that of the starting material. Also they were considerably better than that of the Co 60 irradiated sample of Example 9C. The jet-cooked pastes of Examples 8A, B, C, and D after standing 24 hours at room temperature showed a definite pattern of improvement in preventing paste retrogradation (settling out of solids) due to the modification. The improvement was 14>10>6>3 weight percent of the reagent, whereas the wheat starch starting material and Example 9C settled out in 1 hour. It is to be understood that the foregoing detailed description is given by way of illustration and that modification and variations may be made therein without departing from the spirit and scope of the invention. TABLE VIII______________________________________ 2% Addition of sample to unbleached handsheetsExample % Burst* % Tensile*______________________________________3A 47 343C 55 324 49 285 50 318A 55 338A (washed) 55 328B 51 298C 47 318D 42 319C 32 21starting material 17 5(wheat starch)______________________________________ *% Increase over control paper containing no sample.

Acrylic monomers are grafted onto starch-containing materials by a novel dry state process in which small amounts of peroxides chemically initiate the free radical reaction. Since the process is dry and the resultant products contain no contaminants, it is unnecessary to isolate, wash, and dry them before use. The products are useful in the paper and mineral separation industries.

FIELD OF THE INVENTION This invention relates to a refrigerator, more particularly to a refrigerator having cereals and/or kimchi storage function and making it possible to transmit cool air to the inside of cereals and kimchi storage locations. BACKGROUND OF THE INVENTION FIG. 1 shows a conventional multifunction rice barrel. The multifunction rice barrel comprises a window 2 for seeing the amount of a remaining rice in rice barrel 1, a withdrawal box 4 withdrawing rice in rice barrel for a multistage storage room 5 for storing various kinds of foods and an door 6 for the multistage storage room 5. This conventional multifunction rice barrel can store rice and other various kinds of foods. However, since the temperature in the rice barrel 1 is not constant, there is a problem that rice and other foods, can degenerate. Further, since this conventional rice barrel needs a special kimchi barrel or earthenware for storing kimchi and user should purchase and store much goods separately, storage is extravagant, difficult for a long term and requires a wide space. SUMMARY OF THE INVENTION Accordingly, the object of the present invention is to provide a multifunction refrigerator needing a small space for establishing and including kimchi storage room, cereals storage room and cold storage room. Other object of the present invention is to provide a multifunction refrigerator for storing kimchi for a long term. Further object of the present invention is to provide a multifunction refrigerator for storing cereals such as rice etc. for a long term. To accomplish these objects, the multifunction refrigerator according to the present invention comprises an evaporator for generating cool air from a wall face of a refrigerator and a first partition for conducting the cool air generated from said evaporator into a cold-storage room and a cereal storage room, and dividing the refrigerator into two parts of the cold-storage room and the cereals storage room. And, this refrigerator may comprise an evaporator for generating cool air from a wall face of a refrigerator and a second partition for transmitting cool air generated from said evaporator and thereby maintaining kimchi storage room at low temperature, and inhalation fan for inhaling cool air. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a rice barrel in accordance with an embodiment of convention art. FIG. 2 is a front view showing a multifunction refrigerator in accordance with an embodiment of the present invention. FIG. 3 is a sectional view taken along A--A of the multifunction refrigerator shown in FIG. 2. FIG. 4 is a sectional view taken along B--B of the multifunction refrigerator shown in FIG. 2. FIG. 5 is an enlarged sectional view of a withdrawal part shown in FIG. 4. FIG. 6 is a sectional view taken along C--C of the multifunction refrigerator shown in FIG. 2. FIG. 7 is a enlarged view of D part shown in FIG. 6. FIG. 8 is a side elevation of multifunction refrigerator in accordance with the present invention to show a state withdrawing cereals storage room from refrigerator. FIG. 9 is a partially sectional view showing a humidity control part in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION From FIG. 2 to FIG. 9, these drawings shows a multifunction refrigerator in accordance with the present invention. The multifunction refrigerator comprises a cold storage room 100 for storing different kinds of foods, cereals storage room 200 for storing rice, miscellaneous cereals etc. and a kimchi storage room 300 for storing kimchi. The cold storage room and the cereals custody room is divided by a first partition 400 having a good thermal conductivity, and the cold storage room and the kimchi storage room 300 is divided by a second partition 500. As shown in FIG. 4, the cereals storage room 200 comprises a rice storage room 204 for storing rice flowed therein through a inflow hole 204', a miscellaneous cereals storage room 205 for storage miscellaneous cereals flowed therein through a inflow hole 205' and a container 209, wherein the miscellaneous cereals storage room 205 should be made vertically and parallel to withdraw rice with the rice storage room 204. As shown in FIG. 5, so as to discharge rice and miscellaneous cereals in the rice storage room 204 and the miscellaneous cereals storage room 205, the cereals custody room 200 comprises a horizontal moving plate 212 for discharging selectively rice or miscellaneous cereals through rice outlet 207 of the rice storage room 204 or miscellaneous cereals outlet 208 of the miscellaneous cereals storage room 205, a first elastic member 213 for returning said horizontal moving plate 212 to its original location by pulling it, a moving screw 214 for moving rice or cereals to any location by its rotation, a second elastic member 216 being connected to one end of the moving screw 214, for rotating the screw 214 by elastic power and an outlet 210 making rice or cereals drop into the container 209. Referring to FIG. 8, this is a side elevation of multifunction refrigerator showing cereals storage room 200 being withdrawn from it. The withdrawn barrel or compartment comprises a guiding rail 241 formed on each side of the cereals storage room 200, guiding rollers 243, 245 for guiding the guiding rail 241 and a supporter 247 which two rollers are axially aligned. Referring to FIG. 9, this is a partial sectional view of a humidity control part in accordance with the present invention. As shown in the drawing, this humidity control part comprises a first evaporation part 920 and a second evaporation part 930. The first evaporation part 920 comprises a water outlet pipe 910 through which a defrosted water generated from the evaporator 700 flows down, a first evaporation dish 921 in which the defrosted water flowing down through pipe 910 is collected, a permeating membrane for permeating the moisture being evaporated from said the first evaporation dish 921, and a inducing cover 925 for inducing the moisture passing the permeating membrane 923 into the cereals storage room 200 through holes 926 formed at its surface. Further, the second evaporation part 930 comprises an outlet pipe 933 for discharging the defrosted water being oversupplied to the first evaporation part 920 and a second evaporation dish 931 for evaporating the water collected through the water outlet pipe 933. As shown in FIGS. 6 and 7, the evaporator 700 is established to be attached on the upper plate of the cold-storage room 100 by two-face tape 110. The first partition 400 for separating the refrigerator into two parts of the cold storage room 100 and the cereals storage room 200, is connected to the evaporator 700 to transmit cool air generated from the evaporator 700 into the cold-storage room 100 and the cereals storage room 200. As shown in FIG. 3, a heat generation member 320 is established at the lower portion of the kimchi storage room 300 to ferment kimchi during custody. A transmitting hole is formed at any location of the second partition 500 for dividing the cool storage room 100 and kimchi storage room 300, to transmit cool air generated from the evaporator 700 into the kimchi storage room 300, and an inhalation fan 800 for inhaling cool air into the kimchi storage is established inside the transmitting hole 510. Non descriptive symbols 600 and 310 are compressor and kimchi storage barrel, respectively. At this state, when the compressor 600 is operated, since the cool air generated from the evaporator 700 of the cold storage room 100 attached on the upper plate, circulates into the cold storage room 100, the cereals storage room 200 and the kimchi storage room 300, the stored foods do not degenerate and can be stored for a long time. Also, the cool air generated from the evaporator 700 attached on the upper plate 110 of the cold storage room, is conducted into the cereals custody room 200 by the first partition 400. That is, since the first partition 400 is connected to the evaporator 700, the cool air generated from the evaporator 700, is conducted to the cereals custody room 200 along the first partition 400. Accordingly, the cool air can prevent miscellaneous cereals in the miscellaneous custody room 205 and rice in the rice custody room 204 from being degenerated. To withdraw cereals in the cold storage room 100, a user should pull a knob 240a formed at the door 240 of the cereals storage room 200. At this time, the cereals custody room 200 is drawn out along the supporter 247 positioned between two guiding rollers 241 and 243. In a state that the cereals custody room 200 is drawn out, to withdraw cereals in it, a user should press a lever down in a quantity selecting part 230. As a user presses the lever, a selected cereal drops into the container 209. After a user has withdrawn a desired quantity of cereal, the user pushes it to return the withdrawn cereal storage room 200. As the cereals storage room 200 gets inside the refrigerator, a gasket 240 positioned at the front side of the door 240 contacts a front portion of the refrigerator. To store rice or cereals in the refrigerator, a user has to pour the rice or the cereals through each inflow hole 204' and 205'. Hereinafter, a process for withdrawing stored rice or cereals will be described in detail. As shown in FIG. 5, if a user wants to withdraw only rice, he should rotate the rotating lever 215, leaving the horizontal moving plate 212 in the original location. According to the rotation of the rotating lever 215, the rotating screw 214 concurrently moves the rice to outlet 210. According to the rotation of the rotating screw 214, the dropped rice from rice storage room 204 through the rice outlet 207 and the rice dropping hole 211 is moved toward the outlet 210 and is dropped into the container 209. After that, as the user releases the rotating lever 215, the rotating screw 214 comes back to its original location by the elastic power of the second elastic member 216. On the other hand, to withdraw miscellaneous cereals, first, a user has to pull the horizontal moving plate 212. In the state which the horizontal moving plate 212 is pulled out, the miscellaneous cereals in the miscellaneous storage room 205 drops down into the rotating screw 214 through a miscellaneous dropping hole 211' coincides with the miscellaneous outlet 208 by movement of the horizontal moving plate 212. At this time, the user should rotate the rotating lever 215 to withdraw miscellaneous cereals. According to the rotation of the rotating lever 215, the rotating screw 214 does concurrently move such food to outlet 210. According to the rotating screw, the dropped miscellaneous cereal from the miscellaneous cereals storage room 205 through the miscellaneous cereals outlet 208 and the miscellaneous dropping hole 211' moves toward the outlet 210 and is dropped into the container 209. After that, as the user releases the rotating lever 215 and the horizontal moving plate 212, the rotating screw 215 and the horizontal moving plate 212, the rotating screw 215 and the horizontal moving plate 212 comes back to the original state by elastic power of the second 216 and the first elastic 213 members. When the evaporator 700 is operated, a frost is generated at its surface. A defrost water generated by elimination of the frost flows into the first evaporation dish 921 along the water outlet pipe 910 and evaporates at the first evaporation dish 921. The vapor evaporated from the first evaporation dish 921 passes through the permeating membrane 923 and flows into the cereal storage room 200 through the holes 926, so that it controls the humidity of the cereals storage room 200. The size of the permeating membrane 923 is fabricated to maintain a humidity of 65%. A defrost water oversupplied in the first evaporation dish 921 is flowed into the second evaporation dish 931 through the water outlet pipe 933 and is evaporated by the heat of condenser 935 again. As described before, the multifunction refrigerator in accordance with the present invention can store foods, cereals and/or kimchi for a long time by supplying cool air generated from an evaporator into a cold storage room, a cereals custody room and a kimchi custody room. In addition, since one refrigerator includes a cold storage room, cereals storage room and kimchi storage room, the present invention needs a small space therein and can serve a user's convenience. Although the invention has been described in conjunction with specific embodiments, it is evident that many alternatives and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, the invention is intended to embrace all of the alternatives and variations that fall within the spirit and scope of the appended claims.

This invention relates to a multifunction refrigerator for transmitting cool air into a cereal storage room and kimchi storage room, comprising an evaporator 700 for generating cool air from a wall face of the refrigerator and a first partition 400 for conducting the cool air generated from said evaporator 700 into a cold storage room 100 and cereal storage room 200, and dividing the refrigerator into two parts of the cold storage room 100 and the cereals custody room 200. And, this refrigerator also comprises an evaporator 700 for generating cool air from a wall face of a refrigerator and a second partition 500 for transmitting compulsorily cool air generated from the evaporator 700 and thereby maintaining kimchi storage room 300 at low temperature, and inhalation fan for inhaling cool air.

FIELD OF THE INVENTION The present invention relates to a method for routing calls from a terminal in a first telecommunication network, for example an intranet, to any terminal in an external telecommunication network, the interworking between said networks taking place through one of several interworking units or so-called gateways. BACKGROUND OF THE INVENTION The Problem Areas Problem Intranets Intranets can exceed country borders, and in fact many corporate networks are covering nearly the whole world. The cost of communicating within an intranet is usually much lower than using external communication services, and the intranets usually do not see the country borders. This means that the cost of communicating within an intranet is less dependant on the geographical distance between the endpoints and more on initial investment in network infrastructure. This is in sharp contrast to the charging involved when using commercial telephone services, where distance and duration of call more directly determines the cost of a call. New emerging standards within video and audio conferencing now make it possible to have audio and video conferences/calls within PSTN (ISDN) networks, the Internet, Intranets and Local Area Networks. Since other network domains now support making audio and video conferences/calls, the need for ways of interworking between these different kind of networks has emerged. These interworking units are called gateways, and they provide the conversions necessary (protocol, audio format, video format etc.) for endpoint/terminals residing in different kinds of networks, to be able to communicate with each other. There are no limitations on the number of gateways which can be connected to these networks, which means that an intranet can have access to several gateways in order for a terminal inside the intranet to call e.g. an ISDN video conferencing terminal. Because of cost issues it would be desirable for example to establish a connection through the gateway residing closest to the receiving party on e.g. the PSTN or ISDN network. For example, since an intranet can cross country borders it could be desirable to place one gateway in each country and avoid expensive international calls by always calling out through the gateway residing in the country where the receiving party is located. Known solutions and problems with these Related problems have probably been solved for circuit-switched (telephony) networks, where routing tables assure that distributed companies with local telephone networks route as much as possible of each call within the local network before entering the public telephony network. This should apply to packet networks (intranets, LANs etc.) as well, but routing tables must with this solution be entered manually. This invention proposes inter alia a way for a dynamic generation of routing tables for audiovisual communication when going from packet-networks to other networks (circuit- and packet networks) via gateways by the automatic update of routing information from gateways to the routing entities within the packet network. OBJECTS OF THE INVENTION An object of the invention is to provide a method whereby such routing of calls can be affected in a generally most optimal manner. Another object of the invention is to provide a method wherein such routing may be affected in the most cost effective manner. Still another object of the present invention is to provide wherein such routing may be affected in the most resource effective manner. Yet another object of the invention is to provide a method selection of network operators may be made in an effective manner. An object of the invention is also to provide a combined optimalization of such routing and selection. BRIEF DISCUSSION OF THE INVENTION These objects are achieved by a method as stated in the preamble, which according to the present invention is characterized in that there is used at least one routing entity which routes the call or calls through a gateway (GW 1 , GW 2 ) giving the most optimal route, for example the most cost effective or resource effective route. In other words, the invention proposes inter alia to automatically route interworking calls (i.e. over gateways) from packet-networks through the gateway giving the most cost effective charge by using a routing table which is automatically updated each time a new gateway is introduced into the network. Reference in this invention proposal is done for example towards an emerging ITU standard H.323 for IP based video/audio/data conferencing, but the invention should apply equally to packet networks in which registering functions are available and calls to other networks are available (e.g. Internet, Intranet telephony, voice over IP, etc.). In a specific embodiment of the invention the key approach is for the routing entity (from now on referred to as gatekeeper, logical switch, when referring to audio-visual communication on packet networks) to know which gateways exist, and in what country or region they are connected to the public telephony network. When the gatekeeper knows this, it can for example analyse parts of the E.164 number (given to the gatekeeper by the caller residing inside the packet-network/intranet upon initiation of an interworking call) for the receiving party outside the intranet in order to route the call to the most appropriate gateway. In this way as much as possible of the call propagates within the packet-network/intranet and that the most local gateway to the receiving party (charging wise) is selected for putting the call out on the public telephony network. Further features and advantages will appear from the following description taken in connection with enclosed drawings, as well as from the appending patent claims. BRIEF DISCLOSURE OF THE DRAWINGS FIG. 1 is a simplified view indicating a first embodiment of network configurations, wherein the method according to the present invention can be applied. FIG. 2 is an extract of FIG. 1, on a larger scale, and completed with further details including an appropriate table. FIG. 3 is a simplified view illustrating another embodiment of the present method, especially the use of gateway-table for operator priority. FIG. 4 is a simplified view of still another embodiment of a network configuration wherein the method according to the invention can be applied, especially in connection with use of gateway-table for resource management. FIG. 5 illustrate a table wherein various gateway functions are combined. FIG. 6 is yet another network configuration illustrating another aspect of the present invention, especially in connection with using an intranet with optimazing gateways as a transferring network or backbone for two or more external networks. DETAILED DESCRIPTION OF EMBODIMENTS In connection with FIG. 1 there is illustrated an example of how the method according to the present invention can be applied. Basically, the invention suggests a method for routing calls from a terminal in a first telecommunication network, for example an intranet or a packet-network, to any terminal, for example terminal B, in an external telecommunication network, PSTN, the interworking between said networks taking place through one of several interworking units or so-called gateways, GW 1 and GW 2 . FIG. 1 is a simplified view. A more complex view would be where the intranet includes several gatekeepers and at least two types of gateways (i.e. gateways to both PSTN(POTS) which is audio only, and gateways to ISDN video-conferencing with both video and audio). Caller A wants to make a call to receiving party B. Caller A is calling from a terminal (e.g. a PC-terminal with client software and hardware compliant with ITU-T H.323 (ref. 1), while receiving party B is using a POTS telephone. The gatekeeper GK, being the logical switch, is responsible for routing the call to the appropriate gateway. The issue is for the gatekeeper to choose GW 2 for the call since that gateway resides in the same country as the receiving party B and therefore will lead to a less expensive call since it will be a national call instead of an international call. Choosing GW 1 will lead to an international call between for example Sweden and Norway over the PSTN network. When a gateway is introduced into the intranet, it has to register with the gatekeeper(s) (according to standards for audio-visual communication over packet networks i.e. ITU-T H.323 (ref. 1)). The gateway initiates this by sending out a multicast message (according to ITU-T H.225 section for RAS signalling (ref. 4)) called GRQ (Gatekeeper Request). The gatekeeper which is willing to take the gateways registration will return a GCF (Gatekeeper confirmation). Upon receiving the GCF, the gateway will send an RRQ (Registration Request) to the gatekeeper which has accepted its registration. One of the message fields in this message is called nonStandardData. It is part of this invention's idea to use this field (until a more specific country- or area-code attribute is specified for this message) to send the country (or area) code for the PSTN network this gateway connects to. The gatekeeper will store this country code in a table either locally or in a central database for the whole intranet. The latter is necessary if several gatekeepers coexist in the intranet. The table will have at least 2 columns, where one is the country code (according to E.164) ref. 3)) and the other is the callSignalAddress (sequence of TransportAddress) (ITU-T H.225 (ref. 4)). A complete table of all the gateways will be registered in this gateway-table, as shown in FIG. 2, and in addition an entry will be added to the table describing which address to connect to as default. When caller A wants to set up a call to receiving party B (+47 66842634), the gatekeeper will analyse the country code part of the E.164 (ref. 3) destinationaddress in the Setup (ITU-T H.225 (ref. 4)) message from caller A to the gatekeeper. By doing a lookup in the gateway-table, the gatekeeper will find that a gateway connecting to country code 47 is reachable from the intranet. The gatekeeper will then use the corresponding callSignalAddress entry to route the call to the gateway which is residing in the same country as the receiving party. If the gatekeeper is unable to find a matching country code entry in the gateway-table, the gatekeeper will use the callSignalAddress associated with the default entry in the table. In the particular example the gatekeeper will see that caller A wants to call 47 66842634, and therefore use the table to find out that GW 2 should be contacted at address www.xxx.yyy.zzz. It is to be understood that there is no limitation on this invention saying that this should apply to intranets crossing country borders only. One could use the present method for intranets crossing areas within a country as well, since calling within one area of the country is usually cheaper than crossing areas. In this case the gateway-table would have to be enhanced with an additional column listing the different gateways' area codes (in addition to their country code). In addition to this, and as illustrated in FIG. 2, it could be advantageous to add more intelligence to the search for the best gateway. In cases where a matching country (or area) code is not found, it could be desirable to introduce a scheme/algorithm where the country (or area) code closest in number value to the desired one is chosen instead of the default entry. This is based on the fact that country (and area) codes for adjacent countries (or areas) usually has adjacent numbers for country (and area code). In cases where this is not good enough, the gateway table can be manually configured to map country (and area) codes having no gateway represented, to existing gateways in the closest country (or area) charging-wise. E.g. if an intranet has gateways to Sweden and Italy and a caller inside the intranet wants to call an external destination in Norway, it would probably be wise to route the call through the gateway in Sweden. This means that an entry for country code 47 (Norway) would be manually configured to map to the callSignalAddress of the gateway residing in Sweden. In the new situation arising many places in the world where traditional telephone operators no longer has monopoly in their own countries, it could be advantageous to be able to route calls more intelligently depending on which operator gives the best offer at any time. With this invention this could be done by letting the gateway register with information on what operator is connected to the gateway on the PSTN/telephone network side. The gatekeeper(s) would keep a table updated (by adding information as gateways register) of all the gateways addresses and their corresponding PSTN operators. The table could be arranged as illustrated in FIG. 3, and then so that the operator giving the best offer on PSTN/telephony charge at any time would be listed at the top with highest priority. This will make it possible to negotiate better deals with the different operators by easily being able to switch priority of gateway choice. So far this invention proposal has focused on the charging issue of the invention. The invention can however be applied in a way where focus in on e.g. quality of service or resource handling, as this is illustrated in FIG. 4 . The only difference would be the implementation of the gateway table and what data is sent from the gateways upon registration. More precisely, if e.g. the gateways send along the total number of ports (lowest bandwidth resolution line it has available e.g. 64 kbit/s—higher bandwidth is served with one call using several ports on the gateway e.g. 384 kbit/s=6×64 kbit/s=6 ports) to the gatekeeper(s), a table can be made showing available ports available at any time. If a gatekeeper wants to set up a call through a gateway, it would refer to the table and see which gateway has available ports and thereby do resource management. After selecting a gateway with available ports, the number of available ports available for the chosen gateway will have to be reduced by the amount of ports the current call is using. Upon completion of the call, the gatekeeper will have to add the number of ports to this gateway in the table. If all entries in the table have 0 ports available, the call would have to be rejected as there are no gateway ports available to support the call. The introduction of different criteria for routing calls leads to the combined solution where country code, operator and number of ports are integrated into one table to give a more intelligent way of routing calls, which is illustrated by the Table in FIG. 5 . The table could be designed to match the criteria the “owner” of the intranet wants to use when making external calls through gateways. By this is meant that e.g. in the case where someone wants to make a call to country code 47, and all ports on the preferred operators gateway to that country is occupied, one might choose to do one of the following: 1. Choose same operator, but go through gateway. residing in another country, or . . . 2. Choose next operator on the list, which has a gateway to country 47 with available resources (ports). In FIG. 6 there is illustrated how the invention could also be used when one wishes to use the packet network (intranet) as a transport or backbone network for other external networks. Subscriber. C is a PSTN subscriber, and he wishes to call another PSTN subscriber in e.g. another country or region. He would normally just call the number to B and have the call set up through the international or national PSTN network. However, another option would be for C to call a gateway to a packet network (intranet) and route the call through that network in order to avoid expensive long distance calls or in cases where subscriber B cannot be reached directly going only over the PSTN network (e.g. errors on line, all lines occupied etc.). The packet network would then use the invention described earlier in this document to route the call to the gateway residing closest chargingwise to subscriber B. In order for subscriber C to call B this way he must input number both to the gateway he wishes to use going into the packet network and the number to subscriber B. This however, is not different from a traditional call into the packet-network from an external network and hence vill not be further described here. Advantages The invention gives the owner of the intranet: Cost reductions since the number of expensive international or long distance calls can be reduced since gateways can be put in countries which the intranet already has direct access to and has a considerable amount of traffic to. Other solutions have been proposed that should make the owner of the intranet able to negotiate better deals with telephony operators by the use of gateway routing tables. Flexibility to negotiate better deals with different telephony service providers by automatically routing the bulk part of the calls to the provider with the best offer (e.g. by setting the number 1 priority or default entry in the gateway-table to point to the “best offer” provider). Load distribution by selecting different gateways for different destinations and thereby automatically distribute load geographically. Redundancy if gatekeeper can choose another gateway in another area/country if problems arise in another gateway or public telephony network. Resource Management through scan of ports available at any time at each gateway. Use of intranet as transport or backbone network for external networks.

The present invention relates to a method for routing calls from a terminal in a first telecommunication network, for example an intranet, to any terminal in an external telecommunication network, the interworking between said networks taking place through one of several interworking units or so-called gateways (GW), and in order to provide a method which in a more effective manner can optimise such interworking between such networks, it is according to the present invention suggested that there is used at least one routing entity which routes the call or calls through a gateway (GW 1 , GW 2 ) giving the most optimal route, for example the most cost effective or resource effective route.

BACKGROUND [0001] The invention generally relates to a downhole valve that has incrementally adjustable open positions and a quick close feature. [0002] In well testing and production, it is often desirable to regulate the flow of well fluid into a tubing string. For this purpose, the tubing string may include a valve. As a more specific example, a particular type of valve is a multiple position valve, or choke. In general, the choke may have a closed setting that blocks well fluid communication through the valve, and the choke may also have multiple discrete open settings. Each open setting establishes a different cross-sectional flow area for the choke, and thus, the choke may have multiple incrementally adjustable open positions. [0003] A conventional choke may contain a J-slot mechanism to transition the choke through its settings. With a J-slot mechanism, the choke cannot be randomly changed between settings; but rather, the choke's open and closed settings follow a predefined order, or sequence, which is established by the corresponding J-slot groove. Each setting change may be effected, for example, by cycling the pressure in a control line. [0004] The sequence that is imposed by the J-slot mechanism may limit how quickly the choke can be closed. For example, the choke may currently be at open setting number two, out of eight open settings (as an example). To transition the choke to the closed setting from open setting number two, the choke may need to transition through all of the intervening settings (i.e., open setting number three through open setting number eight) before the closed setting is reached. SUMMARY [0005] In an embodiment of the invention, a valve that is usable with a well includes an indexer and a closing mechanism. The indexer includes a profile to establish a sequence of open settings for the valve, and the indexer is adapted to respond to first control stimuli to transition the valve through the settings according to the sequence. The closing mechanism is adapted to operate independently of the sequence in response to a second control stimulus to close the valve. [0006] In another embodiment of the invention, a system that is usable with a well includes a string, a first control line and a second control line. The string includes a valve to control fluid communication between the well and a central passageway of the string. The valve includes an indexer and a closing mechanism. The indexer includes a profile to establish a sequence of open settings for the valve, and the indexer is adapted to respond to first signals to transition the valve through the settings according to the sequence. The closing mechanism is adapted to operate independently of the sequence in response to a second signal to close the valve. [0007] In yet another embodiment of the invention, a technique that is usable with a well includes providing a profile to establish a sequence of open settings for a valve. The technique includes transitioning the valve through the open settings in response to first stimuli; and in response to a second stimulus, closing the valve. The closing of the valve is independent of the sequence. [0008] Advantages and other features of the invention will become apparent from the following drawing, description and claims. BRIEF DESCRIPTION OF THE DRAWING [0009] FIG. 1 is a schematic diagram of a well according to an embodiment of the invention. [0010] FIGS. 2 and 3 are partial cross-sectional views of the choke of FIG. 1 for different operational states of the choke taken along line 2 - 2 of FIG. 1 according to an embodiment of the invention. [0011] FIG. 4 is an exploded perspective view of incrementing and indexing sleeves of the choke according to an embodiment of the invention. [0012] FIGS. 5 , 6 , 7 , 8 and 9 are illustrations depicting interaction between the incrementing and indexing sleeves according to an embodiment of the invention. DETAILED DESCRIPTION [0013] Referring to FIG. 1 , an embodiment 10 of a well in accordance with the invention includes a wellbore 20 that is lined with a casing string 22 , although the wellbore 20 may be cased or uncased, depending on the particular embodiment of the invention. A tubular string 30 extends into the wellbore 20 , and as depicted in FIG. 1 , the string 30 extends through a particular production zone 50 , which may be isolated by upper 54 and lower 58 packers, for example. [0014] It is noted that although FIG. 1 depicts the wellbore 20 as being a vertical wellbore, the string 30 may likewise extend through a lateral, or deviated wellbore, in accordance with other embodiments of the invention. Additionally, the well 10 may be a subterranean or a subsea well, depending on the particular embodiment of the invention. Thus, many variations are contemplated and are within the scope of the appended claims. [0015] The string 30 includes a flow control device, or valve, such as a downhole multi-position choke 60 . As described herein, the choke 60 has a closed setting to block all well fluid through the choke and multiple discrete open settings. Each open setting establishes a different cross-sectional area through the choke's well fluid flow path. For example, one of the open settings may establish a twenty-five percent cross-sectional area; another open setting may establish a seventy-five percent cross-sectional area; and another open setting may fully open well fluid communication through the choke 60 . [0016] In accordance with embodiments of the invention described herein, the open settings of the choke 60 cannot be randomly selected, but rather, the setting selection is subject to a predefined selection order, or sequence. As a more specific example, in accordance with some embodiments of the invention, the choke 60 transitions from one open setting to the next in response to control stimuli, such as pressure signals, which are communicated through an open choke control line 64 . The control line 64 may, for example, extend between the choke 60 and a surface pressure source 70 (as an example). [0017] As a specific example, an exemplary pressure signal to transition the choke 60 from one open setting to the next may involve pressurizing the control line 64 (via the pressure source 70 ) above a pressure threshold and thereafter bleeding the control line pressure below the pressure threshold. For example, if the choke 60 is currently at the fifty percent open setting (as a non-limiting example), then the application of the next pressure signal may cause the choke 60 to transition to the sixty-seven percent open setting (as a non-limiting example). It is noted that other types of pressure signals other than a simple pressure up and down cycle may be used to cycle the choke 60 through its open settings, in accordance with other embodiments of the invention. [0018] For purposes of closing the choke 60 , a control stimulus, such as a pressure signal (a pressure that exceeds a predefined threshold, for example), may be applied via a close control line 62 , a control line that may extend between the choke 60 and a surface pressure source 68 (as an example). The ability of the choke 60 to transition to the closed setting is independent of the above-described selection sequence for the open settings and thus, does not depend on the current setting of the choke 60 . Therefore, in response to a single pressure cycle in the control line 62 , the choke 60 is capable of bypassing any part of the selection sequence to immediately transition from any one of the open settings to the closed setting. In accordance with some embodiments of the invention, a single pressurization of the control line 62 causes the choke 60 to rapidly close, regardless of the current setting of the choke 60 . [0019] As a more specific example, the control lines 62 and 64 may be pressurized in the following manner for purposes of controlling the choke 60 in accordance with some embodiments of the invention. In general, to select a particular open setting, the pressure in the control line 62 may be maintained below a minimum threshold; and the pressure in the control line 64 may then be manipulated to cycle the choke 60 until the desired setting is reached. More specifically, in accordance with some embodiments of the invention, each time the pressure in the control line 64 is pressurized above a certain threshold, the choke 60 advances pursuant to the selection sequence from one open setting to the next. After each setting change, the control line 64 may be bled off, or de-pressurized, below the minimum pressure threshold and subsequently re-pressurized to advance the choke 60 to the next setting. As set forth above, at any time, the control line 64 may be de-pressurized and the control line 62 may be pressurized for purposes of closing the choke 60 . [0020] FIG. 2 depicts a partial cross-sectional view of the choke 60 , taken along line 2 - 2 of FIG. 1 . In particular, FIG. 2 depicts the left-hand view of the cross-sectional diagram on the left-hand side of a longitudinal axis 100 . The longitudinal axis 100 , in general, is coaxial with the longitudinal axis of the string 30 near the choke 60 . As can be appreciated by one of skill in the art, the choke 60 is generally symmetrical about the longitudinal axis 100 , with the right-hand cross-section being omitted from FIG. 2 . [0021] In general, the choke 60 includes a housing 110 that includes radial ports 120 (one radial port 120 being depicted in FIG. 2 ) that are formed in the housing 110 . Although the housing 110 is depicted in the figures as being an outer housing, it is noted that in other embodiments of the invention, the housing 110 may be an inner housing. Fluid communication between the radial ports 120 and a central passageway 111 (which is in fluid communication with a central passageway of the string 30 ) of the choke 60 is controlled by the axial position of a sleeve 140 , which may be an inner (as depicted in the figures) or outer sleeve, depending on the particular embodiment of the invention. [0022] For the state of the choke depicted in FIG. 2 , the choke 60 is fully open, i.e., the choke 60 is in the open setting at which full fluid communication occurs through the ports 120 . For the other open settings of the choke 60 , the sleeve 140 moves upwardly to partially close fluid communication through the ports 120 , and the extent of the upward travel of the sleeve 40 is a function of the particular open setting. [0023] The sequencing of the choke 60 is controlled by the action of an indexer, which, as an example, may include an incrementer, such as an exemplary incrementing sleeve 160 , and an indexing sleeve 180 . The incrementing 160 and indexing 180 sleeves generally circumscribe the longitudinal axis 100 . In general, the indexing sleeve 180 includes an outer cam groove 182 that spirally, or helically, extends around the longitudinal axis 100 and is engaged by a pin 190 that is attached to and radially extends from the interior of the housing 110 . [0024] The incrementing sleeve 160 , as described below, responds to pressure signals in the control line 64 (via a floating piston 150 described below) to move axially, rotate and engage the indexing sleeve 180 . The engagement of the indexing sleeve 180 by the incrementing sleeve 160 causes the indexing sleeve 180 to axially change positions and rotate. The axial translation of the indexing sleeve 180 , in turn, causes a corresponding axial position translation of the sleeve 140 to change the position of the sleeve 140 with respect to the radial ports 120 . Therefore, from the fully open setting of the choke 60 that is depicted in FIG. 2 , each cycle of the incrementing sleeve 160 (as described below) causes a corresponding translation and rotation of the indexing sleeve 180 to incrementally advance the sleeve 140 upwardly to a different position and thus, establish a different open setting for the choke 60 . [0025] As depicted in FIG. 2 , the choke 60 includes a spring 170 (a coiled spring, for example) that resides between an inner annular shoulder 112 of the housing 110 and an outer annular shoulder 165 of the incrementing sleeve 160 for purposes of returning the incrementing sleeve 160 to an initial position after the incrementing sleeve 160 incrementally adjusts the position of the indexing sleeve 180 , as described below. The floating piston 150 resides in an annular cavity that is formed between the incrementing sleeve 160 and a lower shoulder 142 of the sleeve 140 . The piston 150 isolates the control lines 62 and 64 . As depicted in FIG. 2 , the control line 62 extends through a radial port of the housing 110 to establish fluid communication between the control line 62 and the region below the piston 150 ; and the control line 64 , via a radial port in the housing 110 , establishes fluid communication above the piston 150 . [0026] Referring to FIG. 4 in conjunction with FIG. 2 , the choke 60 may be operated in the following manner. It is assumed for this discussion that the close control line 62 is de-pressurized (i.e., the control line 64 has a pressure below a minimum pressure threshold). When pressure is applied to the control line 64 , the floating piston 150 moves in a downward position and moves the incrementing sleeve 160 toward the indexing sleeve 180 while compressing the spring 170 . Due to this downward translation of the incrementing sleeve 160 a lower finger 168 of the incrementing sleeve 160 contacts one of a plurality of stepped faces 186 of the indexing sleeve 180 . The stepped faces 186 collectively form a profile that establishes the selection sequence for the open settings of the choke 60 . As depicted in FIG. 4 , in accordance with some embodiments of the invention, the stepped faces 186 may be formed in the upper end of the indexing sleeve 180 . [0027] In other embodiments of the invention, the incrementing sleeve 160 may include a plurality of fingers 168 . For these embodiments of the invention, the pattern of stepped faces 186 depicted in FIG. 4 is repeated on the circumference of the indexing sleeve 180 , so that each finger 168 has an associated pattern of stepped faces 186 . [0028] Upon the engagement of the lower finger 168 with one of the stepped faces 186 , the incrementing sleeve 160 pushes the indexing sleeve 180 downwardly, which causes the indexing sleeve 180 to engage an annular shoulder 194 of the sleeve 140 , thereby resulting in incrementing the choke's position. Because the incrementing sleeve 160 and indexing sleeve 180 have cam grooves 162 and 182 , respectively, both of these sleeves rotate while axially translating as soon as they engage with each other. This rotational movement is not transmitted to the sleeve 140 . The translation movement stops when the incrementing sleeve 160 contacts the housing 110 . [0029] When the pressure in the open control line 64 is bled off, the spring 170 axially translates the incrementing sleeve 160 in an upward direction and the sleeve 160 engages the floating piston 150 . Because displacement of the incrementing sleeve 160 is controlled by the cam groove 162 (as further described below in connection with FIGS. 5-9 ), the incrementing sleeve 160 rotates and translates back to its initial position and is therefore ready to engage the next stepped face 186 of the indexing sleeve 180 (which has rotated one incremental position since the last engagement). [0030] FIG. 3 depicts a partial cross-sectional view of the choke 60 , illustrating the choke 60 when in its closed position. For this state of the choke 60 , pressure in the control line 64 is bled off, and the closed control line 62 is pressurized. The floating piston 150 and the sleeve 140 form at least part of a closing mechanism of the choke 60 , in accordance with some embodiments of the invention. More specifically, when pressure is applied to the control line 62 (regardless of the current setting of the choke 60 ), the floating piston 150 moves upwardly and engages the sleeve 140 , thereby pushing the sleeve 140 in an upward direction until the floating piston 150 lodges against an interior annular shoulder 191 of the housing 110 . During this movement, the sleeve 140 engages the incrementing sleeve 180 , which rotates in return due to the cam profile 182 (see FIG. 4 ). Once the sleeve 140 reaches this fully closed position, the indexing sleeve 180 has fully rotated so that it is ready to increment to open setting number one when pressure is once again applied to the open control line 64 . The structure of the closing mechanism may be varied in other embodiments of the invention. [0031] Referring back to FIG. 4 , the cam groove 162 of the increment sleeve 160 has a profile that permits the increment sleeve 160 to rotate after each engagement with the indexing sleeve 180 and then return to its initial position (ready to increment to open setting number one) after engagement with the sleeve 140 . FIGS. 5 , 6 , 7 , 8 and 9 illustrate the interaction between the increment 160 and indexing 180 sleeves and the role of the cam groove 162 , in accordance with some embodiments of the invention. [0032] FIG. 5 depicts the state of the incrementing sleeve 160 and indexing sleeve 180 sleeves when pressure is applied to the open control line 64 (the close control line 62 is assumed to be de-pressurized). This pressure produces an axial force 200 via the floating piston 150 that pushes the incrementing sleeve 160 towards the indexing sleeve 180 , until the indexing sleeve 180 is engaged by the lower finger 168 of the incrementing sleeve 160 . Referring to FIG. 6 , the finger 168 comes into contact with one of the stepped faces of the indexing sleeve 180 . During this translation of the incrementing sleeve 160 towards the indexing sleeve 180 , the pin 164 (see FIG. 3 , for example) traverses the portion 162 a of the cam groove 162 . [0033] Referring to FIG. 6 , after the indexing sleeve 160 and the incrementing sleeve 180 are in contact, they both rotate and axially translate at the same time due to the cam profile 162 of the indexing sleeve 160 and the cam profile 182 of the incrementing sleeve 180 . This interaction transitions the choke 60 to the next open setting. During this translation and rotation of the indexing sleeve 160 with the incrementing sleeve 180 , the pin 164 (see FIG. 3 , for example) traverses the portion 162 b of the cam groove 162 . [0034] Referring to FIG. 7 , upon bleeding of the pressure from the open control line 64 , an axial force 210 is produced by the spring 170 (see FIG. 3 , for example) to push the incrementing sleeve 160 and floating piston 150 (see FIG. 2 , for example) back to their initial positions. Before the axial force 210 is produced the pin 164 is at the intersection of the portion 162 b and 162 c . It has already traversed 162 b and is ready to move into 162 c as soon as the axial force 210 starts being produced. [0035] Referring to FIG. 8 , the pin 164 has finished traversing the portion 162 c of the cam groove 162 , and is ready to cause the incrementing sleeve 160 to rotate and translate on the last portion of the return stroke. Referring to FIG. 9 , the pin 164 then traverses the portion 162 d of the cam groove 162 to place the incrementing sleeve 160 ready to engage to the next position on the next pressurization of the control line 64 . [0036] Other embodiments are within the scope of the appended claims. For example, in accordance with other embodiments of the invention, control stimuli other than pressure signals (such as electrical signals, for example) may be used to select the choke's settings, regardless of whether the setting is one of the multiple open settings or the closed setting. For these embodiments of the invention, the choke may include an electro-mechanical actuator, for example. As another example, in other embodiments of the invention, at least part of the choke's operation may be controlled using stimuli that are applied using a downhole tool (a shifting tool, for example). As other examples, the stimuli used to control the choke may be wireless, hard-wired, etc. Thus, the choke may contain a variety of different control mechanism to responds to the many different types of stimuli, and all of these variations are within the scope of the appended claims. [0037] While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.

A valve that is usable with a well includes an indexer and a closing mechanism. The indexer includes a profile to establish a sequence of open settings for the valve, and the indexer is adapted to respond to first control stimuli to transition the valve through the settings according to the sequence. The closing mechanism is adapted to operate independently of the sequence in response to a second control stimulus to close the valve.

BACKGROUND OF THE INVENTION The present invention relates to a clamping mechanism for clamping an information recording disk such as a compact disk to a turntable during the reproduction of the disk. Conventionally there has been employed a clamping mechanism of the type shown in FIGS. 1 through 3 of the attached drawings. In these drawings, an information recording disk A, such as a compact disk, has a center hole B. A spindle motor C rotates a spindle D to which a turntable E is fixed. A centering member F for centering the information recording disk A has a central portion slidably mounted on the spindle D within the turntable E, and an outer circumferential portion in the form of a tapered portion G which can fit within an inner circumferential edge of the center hole of the disk A. The centering member F is urged upward by a compression spring H provided between the centering member F and the turntable C. A magnetic stopper I fixed on the upper end of a column portion of the turntable E prevents the centering member from coming off the spindle D. A clamper J is provided for pressing and clamping the information recording disk A against the disk carrying surface of the turntable E. As shown in FIGS. 4 through 7, the clamper J is constituted by a pressing member K formed in the shape of an inverted saucer and a ring-like magnet L fixed to the center of the lower surface of the pressing member K. A ring-like pressing member M, which is adapted to be brought into contact with the information disk A, is formed on the outer circumference of the lower surface of the pressing member K, and a shaft hole N into which the spindle D can be inserted is formed in the central portion of the pressing member M. A saucer-like engagement/stopper member O is fixed on the upper surface of the pressing member K, and a circumferential engagement/stopper groove P is formed in the outer circumference between the engagement/stopper member O and the upper surface of the pressing member K. A retaining pawl Q, which is fixed to a vertically movable holder (not shown), engages the circumferential engagement/stopper groove P so that the clamper J is rotatably retained by the holder. During reproduction, when the information recording disk A is mounted on the disk carrying surface of the turntable E, the center hole B of the disk A fits with the tapered portion G of the centering member F so that the disk A is centered relative to the spindle D. When the clamper J is then lowered by the holder, the magnet L of the clamper J is attracted to the stopper I of the turntable E so that the attraction force acts in such a manner that the pressing member M of the pressing member K of the clamper J urges the information recording disk A against the turntable E, and at the same time the top end portion of the spindle D rotatably fits into the shaft hole N of the clamper J. When the turntable E is then rotated by the spindle motor C, the clamper J rotates together with the information recording disk A. FIG. 8 shows another conventional clamper J in which clamp shafts S are vertically movably disposed at predetermined circumferential intervals along a circle on a disk retaining member R, and coil springs T urge the respective clamp shafts S downward. In this case, when a magnet L of the clamper J is attracted to a turntable E, the lower end portions of the clamp shafts S are raised by the attractive force against the elastic force of the respective coil springs T so that an information recording disk is pressed and clamped against the turntable E by the recovery force of the coil springs T. In the former clamp device, however, there have been various drawbacks in that when the thickness of the information recording disk varies as shown in FIGS. 1 through 3, the gap between the surface of the turntable E and the magnet L varies, whereby the clamping force varies with the variations in the thickness of the disk, making the clamping operation unstable. In the latter conventional clamp mechanism, on the other hand, while the variations in the clamping force can be eliminated, additional components such as the clamp shafts S and the coil springs T are required, making the total number of parts large. Also, it is necessary to provide space for arranging the clamp shafts S, etc., making the saucer-like retaining member R large in size. Furthermore, because the clamper has sliding portions in the form of the clamp shafts, there are further disadvantages in that the performance of the mechanism tends to deteriorate over time and highly precise components are required. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a clamp mechanism in which the above-discussed drawbacks of the conventional clamp mechanisms are eliminated. In accordance with the above and other objects, the invention provides a clamp mechanism having a pressing member for pressing directly an information recording disk and a retaining member for retaining a magnet connected to each other through a plate spring whereby, even if information recording disks to be reproduced vary greatly in thickness, the disks will always be clamped reliably and stably. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 through 3 are longitudinal sectional views showing different operations of a conventional clamp mechanism for an information recording disk; FIG. 4 is a plan view of a clamper used in the clamp mechanism of FIGS. 1 through 3; FIG. 5 is a bottom view of the clamper; FIG. 6 is a side view of the clamper; FIG. 7 is a sectional view taken along a line VII--VII in FIG. 4; FIG. 8 is a partially cut-away side view of a clamper employed in another conventional clamp mechanism; FIGS. 9 through 11 are longitudinal sectional views showing different operations of a clamp mechanism for an information recording disk constructed in accordance with the present invention; FIG. 12 is a plan view of a clamper used in the clamp mechanism of FIGS. 9 through 11; FIG. 13 is a bottom view of the clamper; FIG. 14 is a side view of the clamper; and FIG. 15 is a sectional view taken along a line XV--XV in FIG. 12. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the invention will now be described with reference to FIGS. 9 through 15 of the attached drawings. FIGS. 9 through 1 are longitudinal sectional views showing different operations of an information recording disk clamp mechanism constructed in accordance with the present invention, FIG. 12 is a plan view of a clamper used in this clamp mechanism, FIG. 13 is a bottom view of the clamper, FIG. 14 is a side view of the clamper, and FIG. 15 is a sectional view taken along a line XV--XV in FIG. 12. In FIGS. 9 through 11, reference numeral 1 designates an information recording disk such as a compact disk or a video disk, 2 indicates a center hole of the disk 1, 3 a spindle motor driving a spindle 4 to which a central portion of a turntable 5 is fixed, and 6 indicates a rubber sheet adhered to the upper surface of a disk carrying surface of the turntable 5. A centering member 7 for centering the information recording disk 1 has an outer circumferential portion in the form of a tapered portion 8 which can fit the center hole 2 of the disk 1. A central portion of the centering member 7 is slidably mounted on the spindle 4. The centering member F is urged upward by a centering compression spring 9 provided between the centering member 7 and the turntable 5. A stopper 10 made of a magnetic material is fixed on an upper end of a column portion 5a of the turntable 5 by screws so as to prevent the centering member 7 from coming off the spindle 4. A clamper 11 is provided for pressing and centering the information recording disk 1 against the turntable 2. As shown in FIGS. 12 through 15, the clamper 11 is constituted by a retaining member 13 for retaining a ring-like magnet 12, a ring-like pressing member 14 having a diameter larger than that of the retaining member 13, and a plate spring member 15 for concentrically connecting the retaining member 13 and the pressing member 14 to each other so that the members 13 and 14 are movable vertically. A shaft hole 15a into which the spindle 4 can be inserted is formed in the center of the lower surface of the retaining member 13. The magnet 12 is fixed on the lower surface of the retaining member 13 coaxially with the shaft hole 15a. A saucer-like engagement/stopper member 16 is fixed on the upper surface of the retaining member 13, and a circular engagement/stopper groove 17 is formed in the outer circumference between the lower surface of the engagement/stopper member 16 and the upper surface of the retaining member 13. A retaining pawl 19 fixed at the rear surface of a vertically movable member 18 engages the circular engagement/stopper groove 17 so that the clamper 11 is mounted at the rear surface of the holder 18 in such a manner as to be rotatable and slightly movable vertically. The plate spring member 15 is constituted by an inner ring portion 20, an outer ring portion 21, and a plurality of belt-like circumferentially extending spring portions 22 for interconnecting the inner and outer ring portions 20 and 21. The inner ring portion 20 is fixedly embedded in the outer circumferential portion of the retaining member 13, and the outer ring 21 is fixedly embedded in the inner circumference of the pressing member 14. If the plate spring member 15 is molded with resin integrally with the retaining member 13 and the pressing member 14, it is possible to reduce the total number of parts required. The operation of the above-described embodiment will now be described. When the information recording disk 1 is mounted on the turntable 5 for reproduction, the center hole 2 of the disk fits with the tapered portion 8 of the centering member 7 so that the disk 1 is centered relative to the spindle 4 and simultaneously the information recording disk abuts the disk carrying surface of the turntable 5. When the clamper 11 is then lowered by the holder 18, the magnet 12 of the clamper 11 is attracted to the magnetic stopper 10, that is, to the turntable 5, so that the pressing member 14 of the clamper 11 presses and clamps the information recording disk 1 against the turntable 5, while simultaneously the top end portion of the spindle 4 rotatably fits into the shaft hole 15a of the clamper 11. At that time, the clamper is free from the retaining pawl 19 fixed on the holder 18. As the turntable 5 is rotated by the spindle motor 3 in the above condition, the clamper 11 rotates together with the information recording disk 1. As shown in FIGS. 9 through 11, even if the information recording disks vary in thickness, the gap between the lower surface of the magnet 12 and the upper surface of the stopper 10 remains constant. The pressing member 14 pressed by the information recording disk is however moved upward by the elastic transformation of the plate spring member 15 in accordance with the thickness of the information recording disk 1 so that the information recording disk 1 is pressed and clamped against the turntable by the recovery force of the plate spring member 15. The thicker the information recording disk 1, the more strongly is the disk 1 pressed and clamped against the turntable 5. According to the present invention as described above, in the clamp mechanism for clamping an information recording disk having the clamper 11 arranged to press and clamp the information recording disk 1 against the turntable 5 by means of the attractive force of the magnet 12, the clamper 11 is constituted by the retaining member 13 for retaining the magnet 12, a ring-like pressing member 14 which abuts the information recording disk 1, and a plate spring member 15 for interconnecting the retaining member 13 and pressing member 14 so that the retaining member 13 and the pressing member 14 are vertically movable relative to each other. With this arrangement, the gap between the turntable 5 and the magnet 12 is therefore held constant so that the magnetic attractive force is constant, even if the thickness of the information recording disk 1 varies considerably. Further, the pressing member 14 pressed by the information recording disk 1 can move vertically due to the elastic transformation of the plate spring member 15 in accordance with the thickness of the information recording disk 1, and the information recording disk 1 is pressed and clamped against the turntable 5 by means of the recovery force of the plate spring member 15 so that the clamping state is stably and reliably maintained. Moreover, the plate spring member 15 may be molded from resin integrally with the retaining member 13 and the pressing member 14 so that the total number of parts can be reduced to thereby reduce the overall cost of the device. Because no sliding portion is required, the reliability over time of the device is maintained. Furthermore, in a disk reversing operation in a double-sided disk player or the like, the spring force of the centering spring 9 and the weight of the information recording disk 1 will not be sufficiently great to result in separation from the magnet 12 if the elastic force of the plate spring member 15 is appropriate high.

A clamp mechanism for clamping an information recording disk such as a compact disk or a video disk to a turntable and which provides a strong and reliable clamping force despite variations in the thicknesses of the disks to be reproduced. The clamp mechanism includes a clamper including a magnet retaining member, a ring-like pressing member arranged to abut the information recording disk, and a plate spring member interconnecting the retaining member and the pressing member in such a manner that the retaining member and the pressing member are vertically movable relative to each other.

RELATED APPLICATION [0001] This a nonprovisional application claiming the priority benefit of provisional application Ser. No. 60/197,415, filed Apr. 14, 2000, which is hereby incorporated by reference. FIELD OF THE INVENTION [0002] The present invention generally relates to diagnostic medical imaging apparatus and more particularly to a mammography machine that employs a near-infrared laser as a radiation source. BACKGROUND OF THE INVENTION [0003] Cancer of the breast is a major cause of death among the American female population. Effective treatment of this disease is most readily accomplished following early detection of malignant tumors. Major efforts are presently underway to provide mass screening of the population for symptoms of breast tumors. Such screening efforts will require sophisticated, automated equipment to reliably accomplish the detection process. [0004] The x-ray absorption density resolution of present photographic x-ray methods is insufficient to provide reliable early detection of malignant tumors. Research has indicated that the probability of metastasis increases sharply for breast tumors over 1 cm size. Tumors of this size rarely produce sufficient contrast in a mammogram to be detectable. To produce detectable contrast in photographic mammograms, 2-3 cm dimensions are required. Calcium deposits used for inferential detection of tumors in conventional mammography also appear to be associated with tumors of large size. For these reasons, photographic mammography has been relatively ineffective in the detection of this condition. [0005] Most mammographic apparatus in use today in clinics and hospitals require breast compression techniques which are uncomfortable at best and in many cases painful to the patient. In addition, x-rays constitute ionizing radiation which injects a further risk factor into the use of mammographic techniques as most universally employed. [0006] Ultrasound has also been suggested, as in U.S. Pat. No. 4,075,883, which requires that the breast be immersed in a fluid-filled scanning chamber. U.S. Pat. No. 3,973,126 also requires that the breast be immersed in a fluid-filled chamber for an x-ray scanning technique. [0007] In recent times, the use of light and more specifically laser light to noninvasively peer inside the body to reveal the interior structure has been investigated. This technique is called optical imaging. Optical imaging and spectroscopy are key components of optical tomography. Rapid progress over the past decade have brought optical tomography to the brink of clinical usefulness. Optical wavelength photons do not penetrate in vivo tissue in a straight line as do x-ray photons. This phenomenon causes the light photons to scatter inside the tissue before the photons emerge out of the scanned sample. [0008] Because x-ray photon propagation is essentially straight-line, relatively straight forward techniques based on the Radon transform have been devised to produce computed tomography images through use of computer algorithms. Multiple measurements are made through 360° around the scanned object. These measurements, known as projections, are used to back project the data to create an image representative of the interior of the scanned object. [0009] The detectable signals in an optical breast scanning device are at a very low level. Ambient light must be excluded from the scanning area. Reflections inside the scanner can cause image artifacts or otherwise cause the reconstructed images to be of little use. OBJECTS AND SUMMARY OF THE INVENTION [0010] It is an object of the present invention to provide a scanner for a medical optical imaging device that suppresses optical reflections within the scanning chamber to minimize formation of artifacts to the reconstructed image. [0011] It is another object of the present invention to provide a scanner for a medical optical imaging device that excludes ambient light from entering the scanning chamber. [0012] It is another object of the present invention to provide a scanner for a medical optical imaging device that suppresses reflections inside the optical cavity between the breast and the photodetector. [0013] In summary, the present invention provides a scanner for a medical optical imaging device, comprising an illumination source positioned to direct emitted light into a breast positioned below a support surface; a plurality of detectors positioned to detect light emerging from the breast; and a container disposed below the illumination source and the detectors adapted to trap light reflected from the breast. [0014] The present invention also provides a scanner for a medical optical imaging device, comprising an illumination source positioned to direct emitted light into a breast positioned below a support surface; a plurality of detectors positioned to detect light emerging from the breast; and a collimator having a plurality of holes associated with the respective plurality of detectors to restrict the field of view of the detectors. The holes include non-smooth inside surfaces. [0015] The present invention further provides a scanner for a medical optical imaging device, comprising a scanning chamber including an illumination source positioned to direct emitted light into a breast and a plurality of detectors positioned to detect light emerging from the breast. The scanning chamber includes inside surfaces coated with low-reflectivity material. [0016] The present invention further provides a scanner for a medical optical imaging device, comprising a scanning chamber including an illumination source positioned to direct emitted light into a breast and a plurality of detectors positioned to detect light emerging from the breast. The scanning chamber includes slanted vertical surfaces to direct light from a horizontal plane. [0017] These and other objects of the present invention will become apparent from the following detailed description. BRIEF DESCRIPTIONS OF THE DRAWINGS [0018] [0018]FIG. 1 is a schematic side elevational view of a medical optical imaging device showing a patient positioned on a support with her breast pendent within a scanning chamber made in accordance with the present invention,. [0019] [0019]FIG. 2 is a schematic cross-sectional view of a container disposed below a scanner to capture reflected light from the breast during scanning. [0020] [0020]FIG. 3 is a top plan view taken along line 3 - 3 of FIG. 2, illustrating a honeycomb structure used as a light trap. [0021] [0021]FIG. 4 is an enlarged partial cross-sectional view of a side wall of the container shown in FIG. 2, showing the relationship between the slant angle and the plane of the data acquisition. [0022] [0022]FIG. 5 is a perspective view of a collimator made in accordance with the present invention, showing a plurality of openings to restrict the field of view of detectors. [0023] [0023]FIG. 6 is schematic plan view of the scanner, showing the relationship between the patient's breast, illumination beam, collimator, detector field of view, and the detector. [0024] [0024]FIG. 7 is an enlarged schematic cross-sectional view through line 7 - 7 of FIG. 5, showing a light trap for minimizing off-axis light from reaching the detector. DETAILED DESCRIPTION OF THE INVENTION [0025] A medical optical imaging device is disclosed in U.S. Pat. Nos. 5,692,511, 6,100,520, 6,130,958, which are hereby incorporated by reference. [0026] Referring to FIG. 1, a patient 2 is positioned prone on a scanning table 4 with one breast 6 pendulant in a scanning chamber 8 . A medical optical imaging scanner 10 comprises a collimator 12 secured to an orbit plate 14 and an elevator plate 16 . The collimator 12 is associated with detectors 13 (see FIG. 5). The orbit plate 14 is orbited through one circle around the breast to obtain one slice of data. The elevator plate 16 is moved vertically by drive screws 18 to position the orbit plate 14 at different vertical locations where the orbit plate 14 is again orbited through one circle around the breast to obtain another slice of data. A side curtain 20 is fixed to the underside of the table 4 and the elevator plate 16 to form a barrier for ambient light for the scanning chamber 8 defined by the side curtain 20 , the orbit plate 14 , the elevator plate 16 and a hollow container 21 , such as a cylinder. [0027] The side curtain 20 is foldable vertically to allow it to expand and retract as the vertical plate 16 is lowered or raised. The side curtain 20 includes slanted vertical surfaces 23 . The side curtain 20 is advantageously made from low or nonreflective material. [0028] Referring to FIG. 2, the hollow cylinder 21 has a vertical wall having an inside surface formed into a series of non-vertical steps 22 adapted to direct internal reflections, generally indicated at 24 , downwardly towards the bottom and away from the collimator 12 and the detectors 13 . The reflections 24 originate from the scanning beam 40 impinging on the breast 6 . A bottom wall 26 of the hollow cylinder 21 is provided with a honeycomb structure 28 with openings 30 directed upwardly towards the breast. The honeycomb structure 28 advantageously traps any stray reflections within the hollow cylinder 21 and prevents the reflections from being directed back towards the breast and the collimator 12 . [0029] The steps 22 are preferably formed with horizontal portions 32 and inclined portions 34 , as best shown in FIG. 4. The steps 22 are configured to direct reflected light away from the scan plane, generally indicated by the scanning beam 40 shown in FIG. 2. The angle 35 between the portions 32 and 34 is configured to cause downward reflections of the stray light. The inside surfaces of the hollow cylinder, including the steps and the honeycomb structure, are painted with flat-black paint to make the surfaces low or non-reflective. The openings of the honeycomb structure 28 are preferably hexagonal, as shown in FIG. 3; however, circular, square, triangular, pentagonal or other geometric shapes would also work. [0030] Referring to FIG. 5, the collimator 12 comprises a series of holes 36 through a body 37 that arches around the breast 6 . Detectors 13 are positioned at the end of each hole 36 to detect light coming from the breast 6 due to the laser beam 40 impinging on the breast during scanning. The collimator 12 has a vertical surface 42 that faces the breast. The surface 42 is preferably slanted at about 15 ° off the vertical to direct any stray reflections downwardly toward the hollow cylinder 21 and away from other openings 36 . A lens 43 may be placed in front of each detector 13 to increase light collection capability. [0031] Within the scanning chamber 8 , any surfaces facing the breast is advantageously made low or nonreflective with flat black paint and are slanted from the vertical. In this manner, the chances of any stray reflection finding its way into the holes 36 of the collimator 12 are minimized. [0032] The collimator 12 is shown schematically in plan view in FIG. 6. Each opening 36 has a field of view, schematically indicated at 44 to restrict the amount and direction of light that can be detected by the detectors 13 . [0033] Referring to FIG. 7, a portion of the inside surface of each hole 36 is made non-smooth, such as by providing a series of grooves with slanted walls, or threading the opening with a fine pitch screw thread 46 , to significantly reduce the occurrence of off-axis light, generally indicated at 48 , from the reaching the detector 13 disposed at the other end of the hole. The side walls of the thread 46 change the reflection path of the light 48 , as generally indicated at 49 . The length of the openings 36 limits the field of view of the respective detector 13 . Off-axis light 48 is generally reflected light which is not useful. Through axis light 50 , which has passed through the breast, is used for image reconstruction. [0034] While this invention has been described as having preferred design, it is understood that it is capable of further modification, uses and/or adaptations following in general the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features set forth, and fall within the scope of the invention or the limits of the appended claims.

A scanner for a medical optical imaging device, comprises an illumination source positioned to direct emitted light into a breast positioned below a support surface; a plurality of detectors positioned to detect light emerging from the breast; and a container disposed below the illumination source and the detectors adapted to trap light reflected from the breast.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to the field of piezoelectric resonators, e.g. BAW (bulk acoustic wave) resonators, and particularly to a method of manufacturing an acoustic mirror for a piezoelectric resonator, as well as to a method of manufacturing a piezoelectric resonator. In particular, the present invention relates to a method of manufacturing an acoustic mirror, which is highly planar and has both excellent uniformity in the layer deposition and a planar surface of the entire mirror structure. [0003] 2. Description of the Related Art [0004] Radio-frequency filters based on BAW resonators are of great interest for many RF applications. Substantially, there are two concepts for BAW resonators, so-called thin film BAW resonators (FBAR), on the one hand, as well as so-called solidly mounted resonators (SMR). Thin film BAW resonators include a membrane on which the layer sequence consisting of the lower electrode, the piezoelectric layer, and the upper electrode is arranged. The acoustic resonator develops by the reflection at the upper side and at the lower side of the membrane. In the alternative concept of solidly mounted resonators, an SMR includes a substrate, for example a silicon substrate, on which the layer sequence consisting of the lower electrode, the piezoelectric layer, and the upper electrode is arranged. So as to keep the acoustic waves in the active region in this design, a so-called acoustic mirror is required. It is located between the active layers, i.e. the two electrodes and the piezoelectric layer, and the substrate. The acoustic mirror consists of an alternating sequence of layers with high and low acoustic impedance, respectively, e.g. layers of tungsten (high acoustic impedance) and layers of oxide material (low acoustic impedance). [0005] If the mirror contains layers of conducting materials, such as tungsten, it is recommended, for the avoidance of parasitic capacitances in the filter, to structure (pattern) and substantially limit the corresponding mirror layers to the area below the active resonator region. The disadvantage of this procedure is that the topology resulting hereby can no longer be completely planarized. Due to the unevenness, undesired modes are induced in the resonator and/or a reduction in the quality of the resonator is caused. This problem is very critical in so far as already small steps or remaining topologies of several percent of the layer thickness have significant influence on the operation behavior of such a resonator. [0006] On the basis of FIGS. 1 and 2 , two known methods of manufacturing acoustic mirrors for piezoelectric resonators or BAW resonators are explained in greater detail. [0007] FIG. 1 shows a solidly mounted resonator with structured mirror. The resonator includes a substrate 100 with a lower surface 102 and an upper surface 104 . A layer sequence 106 forming the acoustic mirror is arranged on the upper surface. Between the substrate and the mirror, one or more intermediate layers serving for stress reduction or adhesion improvement may be arranged, for example. The layer sequence includes alternately arranged layers 106 a with high acoustic impedance and layers 106 b with low acoustic impedance, wherein intermediate layers may be provided between the mirror layers. On the upper surface 104 of the substrate 100 , a first layer 106 b 1 with low acoustic impedance is formed. On the layer 106 b 1 , a material 106 a 1 , 106 a 2 with high acoustic impedance is deposited and structured at the portions associated with the active regions of the resonator. Over this arrangement, a second layer 106 b 2 with low acoustic impedance is deposited, upon which in turn a material 106 a 3 , 106 a 4 with high acoustic impedance is deposited and structured section-wise. Upon this layer sequence, again a layer with low acoustic impedance 106 b 3 is deposited. On the resulting mirror structure, a lower electrode 110 , on which again the active or piezoelectric layer 112 , for example of AlN, is arranged, is at least partially formed. On the piezoelectric layer 112 , an insulation layer 114 covering the piezoelectric layer 112 except for the regions 116 a and 116 b is formed. Two upper electrodes 118 a and 118 b in contact with the piezoelectric layer in the portions 116 a and 116 b are formed on the piezoelectric layer. A tuning layer 120 a and 120 b , via the thickness of which a resonance frequency of the resonators can be adjusted, is at least partially arranged on the upper electrode 118 a , 118 b . By the portions of the upper electrode 118 a and 118 b in which it is in connection with the piezoelectric layer 112 , and the underlying portions of the lower electrode 110 , two BAW resonators 122 a and 122 b are defined. The mirror structure 106 shown in FIG. 1 includes λ/4 mirror layers 106 a , 106 b. [0008] In the example of a solidly mounted resonator shown in FIG. 1 , as it is produced by Epcos AG, for example, the metallic layers 106 a are structured without planarizing the resulting topology. The layers 106 b with low acoustic impedance are deposited over the structured layers 106 a , as described above. Thereby, the steps shown in FIG. 1 , which continue in the deposition of the overlaying layers, develop. This procedure is disadvantageous regarding the resulting strong topology in the layers lying above the mirror 106 , in particular, with reduced piezoelectric coupling of the active layer 112 as well as increased excitation of undesired vibrational modes arising. [0009] FIG. 2 shows a further example known in the prior art for solidly mounted resonators with a structured mirror. In FIG. 2 , again a substrate 100 is shown, on the upper surface 104 of which an oxide layer 124 is deposited, into which a pit or depression 126 is introduced. Further intermediate layers may be provided between the oxide layer 124 and the substrate 100 . In the pit 126 , the acoustic mirror is formed, which consists of a layer sequence comprising a first layer 106 a 1 with high acoustic impedance, a layer 106 b with low acoustic impedance, and a layer 106 a 2 with high acoustic impedance. On the surface of the resulting structure, an insulation layer 108 is deposited, on which the lower electrode 110 is at least partially formed. The portion of the insulation layer 108 not covered by the lower electrode 110 is covered by a further insulation layer 128 . On the insulation layer 128 and on the lower electrode 110 , the piezoelectric layer 112 is formed, on the surface of which the upper electrode 118 is in turn partially formed. The portions of the piezoelectric layer 112 not covered by the upper electrode 118 , as well as parts of the upper electrode 118 are covered by the passivation layer 114 . The overlapping areas of lower electrode 110 , piezoelectric layer 112 , and upper electrode 118 define the BAW resonator 122 . [0010] In the example shown in FIG. 2 , the pit 126 , in which the mirror layers 106 a , 106 b are deposited after each other, as described above, is etched into the oxide layer 124 in the area of the resonator 122 to be produced. By one or more CMP (chemical mechanical polishing) processes, the layers outside the mirror pit 126 are removed, as this is described in the U.S. patent application US 2002/154425 A1, for example. [0011] The method described on the basis of FIG. 2 is disadvantageous in that the layers are slightly thinner in the corners of the mirror pit 126 , and a slight key topology in the resonator region 122 , indicated with the reference numeral 130 , develops, which again leads to increased excitation of undesired modes and to reduced resonator quality. SUMMARY OF THE INVENTION [0012] Starting from this prior art, it is an object of the present invention to provide an improved method of manufacturing an acoustic mirror for a piezoelectric resonator, which enables mirrors with excellent uniformity in the layer deposition, as well as a planar surface of the entire mirror structure. [0013] In accordance with a first aspect, the present invention provides a method of manufacturing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has a layer sequence of at least one layer with high acoustic impedance and at least one layer with low acoustic impedance, with the steps of: (a) producing a first layer of the layer sequence; (b) producing a second layer of the layer sequence on the first layer, such that the second layer partially covers the first layer; (c) applying a planarization layer on the first layer and on the second layer; (d) exposing a portion of the second layer by structuring the planarization layer, wherein the portion of the second layer is associated with an active region of the piezoelectric resonator; and (e) planarizing the structure from step (d) by removing the portions of the planarization layer remaining outside the portion. [0014] In accordance with a second aspect, the present invention provides a method of manufacturing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has an alternating layer sequence of a plurality of layers with high acoustic impedance and a plurality of layers with low acoustic impedance, with the steps of: (a) alternately producing the first layers and the second layers; (b) applying a planarization layer on the structure produced in step (a); (c) exposing a portion of the topmost second layer by structuring the planarization layer, wherein the portion of the topmost second layer is associated with an active region of the piezoelectric resonator; and (d) planarizing the structure from step (c) by removing the portions of the planarization layer remaining outside the portion. [0015] In accordance with a third aspect, the present invention provides a method of manufacturing a piezoelectric resonator, with the steps of: (a) producing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has a layer sequence of at least one layer with high acoustic impedance and at least one layer with low acoustic impedance, with the steps of: (a.1) producing a first layer of the layer sequence; (a.2) producing a second layer of the layer sequence on the first layer, such that the second layer partially covers the first layer; (a.3) applying a planarization layer on the first layer and on the second layer; (a.4) exposing a portion of the second layer by structuring the planarization layer, wherein the portion of the second layer is associated with an active region of the piezoelectric resonator; and (a.5) planarizing the structure from step (a.4) by removing the portions of the planarization layer remaining outside the portion; (b) producing a lower electrode substantially at least partially on the acoustic mirror; (c) producing a piezoelectric layer at least partially on the lower electrode; (d) producing an upper electrode at least partially on the piezoelectric layer, wherein a region in which the upper electrode, the piezoelectric layer, and the lower electrode overlap, defines an active region of the piezoelectric resonator. [0016] In accordance with a fourth aspect, the present invention provides a method of manufacturing a piezoelectric resonator, with the steps of: (a) producing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has an alternating layer sequence of a plurality of layers with high acoustic impedance and a plurality of layers with low acoustic impedance, with the steps of: (a.1) alternately producing the first layers and the second layers; (a.2) applying a planarization layer on the structure produced in step (a.1); (a.3) exposing a portion of the topmost second layer by structuring the planarization layer, wherein the portion of the topmost second layer is associated with an active region of the piezoelectric resonator; and (a.4) planarizing the structure from step (a.3) by removing the portions of the planarization layer remaining outside the portion; (b) producing a lower electrode substantially at least partially on the acoustic mirror; (c) producing a piezoelectric layer at least partially on the lower electrode; (d) producing an upper electrode at least partially on the piezoelectric layer, wherein a region in which the upper electrode, the piezoelectric layer, and the lower electrode overlap, defines an active region of the piezoelectric resonator. [0017] The inventive method enables the manufacture of a highly planar acoustic mirror and produces a mirror ensuring both excellent uniformity in the layer deposition and a planar surface of the entire mirror structure. Thus, according to the invention, optimum deposition of the layers lying above the mirror is enabled, which particularly results in high coupling of the piezoelectric layer. Furthermore, according to the invention, also a very homogenous layer distribution in the mirror is achieved, which again leads go high quality of the resonator and to minimum excitation of undesired vibrational modes. [0018] According to the invention, the acoustic mirror is manufactured by a novel combination of depositing, structuring (patterning), and planarizing steps. According to the invention, for this, one or more layers of the mirror are structured, then a planarization layer is deposited on the whole area and opened by an etching process in the resonator region. The resonator region is that region of the mirror associated with the active region of the piezoelectric resonator, wherein the region to be opened is usually selected greater than the active resonator region actually resulting later, due to the adjustment tolerances and due to not exactly perpendicular etching flanks. Then, according to the invention, only the ridges remaining in the overlapping region are removed by a planarization process, for example by a CMP method, wherein the above-described steps are repeated several times depending on the number of the layers to be realized in the acoustic mirror, according to a preferred embodiment of the present invention. [0019] According to the invention, for opening the planarization layer in the critical region, an etching process is thus used, which is selective with reference to the material of the topmost layer of the mirror structure, i.e. this topmost layer serving as etch stop layer. According to the invention, it is thus taken advantage of the fact that such etching processes largely conserve the topology developed in the deposition, whereby the inventive, highly planar, acoustic mirror structure is securely achieved in the critical region of a BAW resonator or piezoelectric resonator. [0020] The highly planar shape of the mirror does not only result from the etching procedure. As mentioned above, a non-planar topology results already in the deposition in the method according to FIG. 2 , because the deposition rate in the corners of the mirror pitch is different than at the center. Moreover, a slight key topology is produced at the center when mechanically polishing. It is the substantial point of the present invention that all depositions take place on planar foundation (and thus no topology develops in the deposition), wherein the planarization steps are chosen so that they do not produce substantial topology in the layers in the resonator region. [0021] Preferably, the second layer to be structured is a conductive layer. The layers for the mirror described in connection with the present invention may be divided into either conductive/non-conductive or non-insulating/insulating layers, or into layers with low or high acoustic impedance. Due to parasitic electrical couplings, when using conductive layers, these are structured independently of whether they have the higher or the lower acoustic impedance. Semiconducting layers may also be used. [0022] According to a first preferred embodiment of the present invention, the layer with high acoustic impedance is a conductive layer, and a structuring step and planarization step of its own is performed for each conductive layer of the mirror structure. In case of a mirror with two conductive layers, at first all layers up to the first conductive layer are deposited. Then, this is structured and planarized, and then all layers up to the second conductive layer are deposited and again structured and planarized ( FIG. 3 ). [0023] In a second embodiment of the present invention, at first all layers of the mirror are deposited and the conductive layers structured and planarized together with non-conductive layers lying therebetween. As opposed to the first preferred embodiment, here the advantage is that only two lithography steps are required, independent of the number of conductive layers. The first embodiment, however, requires two lithography steps each for every conductive layer to be structured and planarized. But the etching process is more intensive, and the planarization is more difficult due to the higher step. [0024] In addition, an etch stop layer may be deposited below the conductive layers, so that the homogeneity/reproducibility of the etch stop may be improved with a selective etching process. [0025] Preferably, the etching processes are performed using a resist mask or using a hard mask, wherein in the second embodiment the use of a hard mask may be necessary due to the longer etching time. [0026] In the above-described embodiment, the plurality of layers may be performed either in an etching process within one chamber or by several successive etching processes in various chambers. [0027] In the above-described first embodiment, in which every conducting layer is structured and planarized separately, the same or different masks may be used to produce substantially equally or differently large layers with this. In the latter case, a mirror structure of truncated cone shape or truncated pyramid shape may be produced, for example. [0028] According to a further embodiment, the present invention provides a method of manufacturing a piezoelectric resonator, wherein at first an acoustic mirror according to the present invention is produced, and then a lower electrode is produced on the acoustic mirror. A piezoelectric layer, on the upper surface of which an upper electrode is at least partially produced, is at least partially produced on the lower electrode. The region in which the upper electrode, the piezoelectric layer, and the lower electrode overlap, defines the active region of the piezoelectric resonator. Furthermore, it may be provided that, prior to producing the lower electrode, one or more layers with suitable acoustic impedance are applied on the produced acoustic mirror, wherein the lower electrode is produced on these layers. In particular, these layers serve for insulation, when the topmost layer in the mirror structure is a conductive layer, or for adjusting certain acoustic properties, such as the dispersion properties of the layer stack, the resonance frequencies of further modes (shear wave modes), or the temperature course. One layer or a plurality of layers of different materials and with different layer thicknesses may be provided. [0029] Furthermore, the present invention provides a method of manufacturing coupled acoustic resonators. Such resonators are arranged vertically on top of each other, i.e. the active part of the resonator (lower electrode, piezoelectric layer, upper electrode) is present twice, separated by one or more intermediate layers, via which the strength of the acoustic coupling may be adjusted. The entire layer stack is placed on the acoustic mirror, like with the individual resonators. BRIEF DESCRIPTION OF THE DRAWINGS [0030] These and other objects and features of the present invention will become clear from the following description taken in conjunction with the accompanying drawings, in which: [0031] FIG. 1 shows a first example of a solidly mounted resonator with structured mirror according to the prior art; [0032] FIG. 2 shows a second example of a solidly mounted resonator with structured mirror according to the prior art; [0033] FIGS. 3( a ) to ( g ) show the steps for manufacturing a highly planar acoustic mirror according to the present invention; [0034] FIGS. 4( a ) to ( j ) show the inventive processing of an acoustic mirror with two conductive layers by multiple depositing, structuring, and planarizing steps according to a first preferred embodiment; and [0035] FIGS. 5( a ) to ( e ) show the inventive processing of an acoustic mirror with two conductive layers by common structuring and planarization of all mirror layers according to a second preferred embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0036] In the subsequent description of the preferred embodiments of the present invention, the same or similarly acting elements are provided with the same reference numerals. [0037] In the subsequent explanations, it is assumed that the layer to be structured has the higher acoustic impedance. The present invention is not limited to this embodiment, the inventive method rather works in fully analog manner when the conductive layer has the smaller acoustic impedance. [0038] On the basis of FIG. 3 , the concept underlying the present invention will be explained in greater detail. In FIG. 3( a ), a substrate 100 is shown, on the upper surface 104 of which a first layer 106 b 1 with low acoustic impedance, e.g. an oxide, is arranged, on which in turn a first layer 106 a 1 with high acoustic impedance, e.g. a tungsten layer or another suitable conductive layer, has been deposited on the whole area. In addition, as it has been described above, one or more intermediate layers may be provided between the substrate and the mirror or between the mirror layers. Using a hard mask or a resist mask, the structure shown in FIG. 3( a ) is subjected to a structuring process by which the first conductive layer 106 a 1 with high acoustic impedance is structured to the shape shown in FIG. 3( b ). [0039] On the structure shown in FIG. 3( b ), then a planarization layer 132 is deposited on the whole area, as this is shown in FIG. 3( c ). The planarization layer 132 is structured using a suitable mask, for example a resist mask or a hard mask, so as to define the portions of the planarization layer 132 to be removed in a subsequent etching process. [0040] The structure shown in FIG. 3( c ) after the masking and after the etching process is shown in FIG. 3( d ). The planarization layer 132 is removed in the region 134 , such that a surface 136 of the first layer 106 a 1 with high acoustic impedance is exposed, and the ridges 132 a , 132 b of the planarization layer 132 only remain in the peripheral region. The portion 134 includes at least the active region of the piezoelectric resonator with which the mirror to be produced is used, wherein the region 134 is usually chosen slightly greater than the active region of the piezoelectric resonator actually resulting later, due to the adjustment tolerances and the oblique etching flanks. [0041] The structure shown in FIG. 3( d ) is subjected to a planarization process leading to the removal of the ridges 132 a and 132 b , for example by a CMP process. The structure resulting after the planarization is shown in FIG. 3( e ), in which the structure comprises a planar surface, wherein the surface 136 of the first layer 106 a 1 is substantially flush with a surface 138 of the portions of the planarization layer 132 arranged on the first layer 106 b 1 with low acoustic impedance. [0042] Subsequently, the steps illustrated on the basis of FIGS. 3( a ) to 3 ( e ) are repeated, so that the structure shown in FIG. 3( f ) with two layers with high acoustic impedance 106 a 1 and 106 a 2 , as well as with two layers with low acoustic impedance 106 b 1 and 106 b 2 results. [0043] On the structure shown in FIG. 3( f ), one or more layers 140 for insulation, when the topmost layer in the mirror structure is a conductive layer, or for adjusting certain acoustic properties are deposited, as this is shown in FIG. 3( g ). The lower electrode, the piezoelectric layer, as well as the upper electrode may be deposited on this structure, for example, in the manner described on the basis of FIG. 2 for producing a BAW resonator. Furthermore, an intermediate layer may be applied on the resonator, on which a further resonator structure is produced, to produce two coupled resonators. [0044] On the basis of FIG. 4 , a first preferred embodiment of the present invention will be explained in greater detail, namely the inventive processing of an acoustic mirror with two conductive layers by multiple depositing, structuring, and planarizing steps. [0045] The procedural steps shown in FIGS. 4( a ) to 4 ( e ) correspond to the procedural steps described on the basis of FIGS. 3( a ) to ( e ), so that renewed description thereof is omitted. A second layer 106 a 2 with high acoustic impedance, for example again a tungsten layer or another suitable metal layer, is then deposited on the structure shown in FIG. 4( e ) on the whole area, as this is shown in FIG. 4( f ). Using the above-described processes, the layer 106 a 2 is then structured, so that the structure shown in FIG. 4( g ) results. A further planarization layer 132 is then deposited on this structure, as this is shown in FIG. 4( h ). This is again structured, and the portion 134 is opened by means of an etching step, to expose the surface 136 of the layer 106 a 2 . [0046] Again, the ridges 132 a and 132 b remain, as this is shown in FIG. 4( i ). After the planarization of the structure shown in FIG. 4( i ), the structure shown in FIG. 4( j ) with the planar surface results, i.e. a structure in which the surfaces 136 and 138 are substantially flush. [0047] On the basis of FIG. 5 , a second preferred embodiment of the present invention will be explained in greater detail in the following, namely the processing of an acoustic mirror with two conductive layers by common structuring and planarizing of all conductive mirror layers. [0048] In FIG. 5( a ), the substrate 100 , on the upper surface 104 of which the insulation layer 108 is arranged, is shown. In contrast to the previously described embodiments, the layer sequence consisting of a first layer 106 b 1 with low acoustic impedance, a first layer 106 a 1 with high acoustic impedance, a further layer 106 2 with low acoustic impedance, and a further layer 106 a 2 with high acoustic impedance is produced on the surface 104 of the substrate 100 according to the second embodiment of the present invention, as this is shown in FIG. 5( a ). [0049] The structure shown in FIG. 5( a ) is then subjected to a structuring process, wherein the lowest layer 106 b 1 is not structured. By customary masking and etching steps, the layer sequence of the layers 106 a 1 , 106 b 2 , 106 a 2 is given the desired structure, as it is shown in FIG. 5( b ). The planarization layer 132 is deposited over this structure, so that the structure shown in FIG. 5( c ) results. Similar to the preceding embodiments, structuring of the layer 132 now takes place such that an upper surface of the second layer 106 a 2 with high acoustic impedance is exposed, and only the ridges 132 a and 132 b remain, as this is shown in FIG. 5( d ). A subsequent planarization step removes the ridges 132 a and 132 b , so that the structure shown in FIG. 5( e ) results. [0050] A lower electrode, a piezoelectric layer, as well as an upper electrode may be applied on the structure shown in FIG. 5( e ), just like on the structure shown in FIG. 4( j ), in order to complete processing the piezoelectric resonator device, as this has already been explained above on the basis of FIG. 3 . [0051] Although the above-described acoustic mirrors according to the preferred embodiments of the present invention comprise a layer with high acoustic impedance, for example a metal layer, as the topmost layer, the present invention is not limited to such a mirror structure. Rather, by means of the inventive method, also a mirror structure the topmost surface of which is a layer with low acoustic impedance may be produced. Furthermore, tungsten layers were mentioned above as layer with high acoustic impedance, and oxide layers were mentioned as layer with low acoustic impedance. [0052] The present invention is not limited to these materials, but other materials having high acoustic impedance or low acoustic impedance, conductive or non-conductive materials, may be equally employed. [0053] As has been described above, the structured mirror layers may be of variable size, so that a structure of truncated cone of truncated pyramid shape results. In principle, the layout of the resonator/mirror may, however, also have any shape (e.g. a trapezoid), whereby an interesting shape results for the three-dimensional mirror. In principle, it is even of advantage when the resonators are not round or rectangular, because regular shapes have many additional (mostly unwanted) vibrational modes of similar resonance frequency. [0054] In connection with the subject of the present invention, however, it is to be noted that the shape of the resonator/mirror is insignificant. The structured layers may thus all be equally large or not (i.e. cuboids or truncated pyramid or the like). [0055] Furthermore, the present invention is independent of the thickness of the layers in the mirror. The acoustic mirror usually is no λ/4 mirror, since there are various modes and wave types (longitudinal/shear waves). For this reason, it is mostly favorable to make the layer construction not periodic, i.e. each layer has different thickness. [0056] The above description of the preferred embodiments substantially refers to the acoustically or electrically relevant layers in the mirror. In addition to these layers, however, also further layers or intermediate layers may be provided. For example, in the mirror structure and in the resonator structure arranged thereupon, one or more structured or unstructured intermediate layers serving as etch stop layers and/or adhesion-promoting layers may be provided. Furthermore, such intermediate layers may serve for further influencing the acoustic properties of the mirror, the resonator structure, or the overall structure. Furthermore, on the resonator structure or the overall structure, one or more structured or unstructured layers for protection and/or for further influencing the acoustic properties of the overall structure may be applied, for example tuning layers and/or passivation layers. [0057] While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and compositions of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention. REFERENCE NUMERAL LIST [0000] 100 substrate, 102 lower surface of the substrate, 104 upper surface of the substrate, 106 layer sequence of the mirror, 106 a layer with high acoustic impedance, 106 a 1 , 106 a 2 layer with high acoustic impedance, 106 b layer with low acoustic impedance, 106 b 1 , 106 b 2 layer with low acoustic impedance, 108 insulation layer, 110 lower electrode, 112 piezoelectric layer, 114 insulation layer, 116 a , 116 b open regions in the insulation layer 114 , 118 upper electrode, 118 a , 118 b upper electrode, 120 a , 120 b tuning layer, 122 BAW resonator, 122 a , 122 b BAW resonator, 124 oxide layer, 126 depression, 128 insulation layer, 130 key topology, 132 planarization layer, 132 a , 132 b ridges of the planarization layer, 134 opened region of the planarization layer, 136 surface of the first 106 a 1 , 138 surface of the planarization layer, 140 layer

A mirror for a piezoelectric resonator consisting of alternately arranged layers of high and low acoustic impedance is manufactured by at first producing a first layer on which a second layer is produced, so that the second layer partially covers the first layer. Then, a planarization layer is applied on the first layer and on the second layer. Subsequently, a portion of the second layer is exposed by structuring the planarization layer, wherein the portion is associated with an active region of the piezoelectric resonator. Finally, the resulting structure is planarized by removing the portions of the planarization layer remaining outside the portion.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims priority from Provisional Application No. 60/207,254, filed May 26, 2000. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to the preparation of a surface treated carbon black and the compounds derived therefrom. The invention relates to the preparation of a surface treated carbon black which has inherently improved dispersability characteristics and provides rubber compounds with improved dynamic mechanical properties. [0004] 2. Discussion of the Prior Art [0005] Improvements in manufacturing of carbon black have allowed for the production of very high surface area carbon black suitable to provide high reinforcement and high levels of wear resistance. With the reduction in the particle size and carbon black structure (the degree of branched connectivity of the carbon black), carbon black becomes increasingly difficult to disperse. [0006] Another phenomenon, carbon black networking, also known as the Payne effect, becomes increasingly prevalent as carbon black content in a rubber compound increases, especially as the particle size decreases and structure increases. This carbon black networking effect is manifested by a dramatic drop in modulus as a function of strain in the rubber compound. This drop in modulus is attributed to a disruption in the carbon black network and is a non-elastic phenomenon. That is to say that the energy required to disrupt this carbon black network is consumed in the disruption of the carbon black aggregate-aggregate interaction and is not recoverable as elastic energy. [0007] The loss in energy due to the Payne effect results in compounds with inherently high loss moduli and, consequently, quite hysteretic. This hysteresis contributes to rolling resistance in pneumatic tire tread compounds increasing fuel consumption. [0008] Previous inventions (Japanese Patent No. 5643/1970, No. 24462/1983, and No. 30417/1968) disclose surface treated carbon black which provide lower cohesive energy density between the particles. However, these materials are not effective in high surface area carbon black. Other patents (U.S. Pat. No. 4,557,306) teach that carbon black modified with Furazan oxides and furazan ring containing compounds provide for improvements in rubber to filler interaction but do not contribute to improvements in the dispersability of the carbon black. And finally, U.S. Pat. No. 4,764,547, teaches that compounds with lower viscosity (thus improved processability) and improved reinforcement properties can be achieved through the use of high surface area carbon black treated with certain amine compounds or quinoline compounds. [0009] Other carbon black coupling agents are known in the art. See, for example T. Yamaguchi et al. in Kautschuk Gummi Kunststoffe , Vol. 42, No. 5, 1989, pages 403-409, which describes a coagent called Sumifine® (i.e. N,N′-bis(2-methyl-2-nitropropyl)-1,6-diaminohexane), and L. Gonz{acute over (a )}lez et al. in Rubber Chemistry and Technology , Vol. 69, 1996, pages 266-272. These agents are not used in common practice. [0010] U.S. Pat. No. 4,764,547 teaches that carbon black treated with conventional antidegradants used in the tire industry can afford an improvement in mixing efficiency. These antidegradants are divided into substituted amines such as paraphenylene diamine and quinoline. Both classes of antidegradants are known as primary antidegradants and function by donating a hydrogen atom to a radical. [0011] The use of an amine compound for carbon surface modification is also disclosed in Japanese abstract J6 2250-073-A. [0012] Carbon black can be difficult to disperse in polymers when the surface area is high. The rate of dispersion of carbon black in polymers is proportional to the viscosity of the polymer, that is, a high viscosity polymer provides faster rates of carbon black dispersion. In the cases of isoprene based rubbers and natural rubber, long mixing time increases the amount of heat generated in the compound and thus reduces viscosity and thus the rate and extent of carbon black dispersion. One technique to overcome this difficulty is to mix carbon black into the polymer several times in internal mixers for short intervals each time. This provides for less time for heat to be generated in the mixer and thus the amount of viscosity reduction is minimized and dispersion is improved, but increasing the number of mixing steps also increases the complexity, time required and expense of the process. SUMMARY OF THE INVENTION [0013] In its primary embodiments, the present invention provides compositions comprising a combination of carbon black and at least one surface treating agent selected from the group consisting of quinone compounds, quinoneimine compounds and quinonediimine compounds. [0014] In its second embodiments, the present invention comprises the methods of combining the surface treating agent with the carbon black. [0015] Third embodiments of the present invention relate to compositions resulting from the addition of the above combination of carbon black and one or more surface treating agents to natural or synthetic polymers. [0016] In its fourth embodiments, the present invention relates to methods of dispersing carbon black in a natural or synthetic polymer composition, to achieve increased dispersibility, improved mixing efficiency and improved processability of the composition, comprising treating the surface of carbon black with at least one surface treating agent selected from the group consisting of quinone compounds, quinoneimine compounds and quinonediimine compounds, or mixtures thereof, and mixing the treated carbon black with the polymer composition. [0017] Other embodiments of the invention encompass details about relative amounts of reactants, surface treating agents, carbon black, rubber compositions and methods of combining carbon black and surface treating agents and dispersing the carbon black into the polymer composition all of which are hereinafter disclosed in the following discussion of each of the facets of the invention. DETAILED DESCRIPTION OF THE INVENTION [0018] The invention provides for the preparation of carbon blacks treated with at least one surface treating agent selected from a class of quinone, quinonediimine or quinoneimine compounds. This treated carbon black shows dramatic improvements in dispersability (as measured by both rate of dispersion and extent of dispersion), improved mixing efficiency and improved processability over carbon black not treated with the surface treating agent. The treated carbon black: enhances the formation of bound rubber in compositions such as natural or synthetic elastomers, plastics or blends thereof and, in particular, butadiene-based rubber, providing improved reinforcement characteristics. The vulcanizates prepared therefrom exhibit improved dynamic mechanical properties as compared to vulcanizates prepared with carbon black not treated with the surface treating agent. [0019] Increasing the surface area of carbon blacks leads to improved treadwear, while decreasing the structure improves tear resistance and fatigue crack growth resistance. However, increasing surface area and/or decreasing structure in carbon blacks makes mixing to adequate levels of dispersion even more difficult. A number of additives such as processing oils, amine antidegradants and furazans can increase the rate of filler incorporation, enhance processability or improve polymer to filler interactions, but do not provide all three of those desireable properties. [0020] High shear and/or long mixing cycles are required to obtain optimum dispersion of fillers such as carbon blacks in rubber compounds. For example, adequate dispersion of N121 carbon black in natural rubber (NR) typically cannot be achieved in a single pass. Therefore, to obtain acceptable carbon black dispersion, most rubber compounds are mixed using two or more mixing passes. This increases the cost of the compound as well as limiting mixing capacity. [0021] This invention focuses on the use of a quinone, quinonediimine or quinoneimine antidegradant as a surface treatment for carbon black. These surface treated carbon blacks exhibit improved mixing characteristics and improved processability, including substantial improvements in dispersability. Improved processability results from the viscosity reduction in natural rubber resulting from use of the treated carbon black. Viscosity reduction is due to peptization, i.e., chain-scission, which results in a decrease in molecular weight. In addition to improved dispersion, this class of chemicals also imparts improvements in bound rubber in natural and synthetic elastomers. [0022] We have found that surface treating carbon black with quinone, quinoneimine, or quinonediimine results in a product that disperses faster in a synthetic and natural rubber tread compound. It is intended that a very broad class of quinones, quinoneimines, or quinonediimines as dispersion agents are suitable for use in the invention, limited primarily by considerations of practicality of physical properties of the agents or the chemical activity of or stearic hindrance caused by various substituted groups on the molecules of the dispersion agents. Preferably, the surface treating agent is a quinoneimine or quinonediimine, more preferably a quinonediimine. With regard to all of the above surface treating agents, the para isomer is preferred. [0023] Effective quinones for use in the invention include those represented by the following formulas Ia and Ib: [0024] wherein R 1 , R 2 , R 3 , and R 4 are the same or different and are selected from hydrogen, hydroxyl, alkyl, alkoxy, aryloxy, alkenyl, cycloalkyl, aryl, aralkyl, alkaryl, alkylamino, arylamino, heterocycle, acyl, aroyl, cyano, halogen, thiol, thioalkyl, thioaryl, amino, nitro, sulfonate, sulfone, sulfonamide, carboxylic acid, alkyl ester and, aryl ester, and the alkyl moieties in the R 1 , R 2 , R 3 , and R 4 groups may be linear or branched and each of the R 1 , R 2 , R 3 , and R 4 groups may be further substituted where appropriate. [0025] Effective quinoneimines for use in the invention include those represented by the following formulas IIa and IIb: [0026] wherein R 1 is selected from hydrogen, hydroxyl, alkyl, alkoxy, aryloxy, alkenyl, cycloalkyl, aryl, aralkyl, alkaryl, alkylamino, arylamino, heterocycle, acyl, aroyl, cyano, halogen, thiol, thioalkyl, thioaryl, amino, nitro, sulfonate, sulfone, sulfonamide, carboxylic acid, alkyl ester and, aryl ester, wherein the alkyl moieties in the R 1 groups may be linear or branched and each of the R 1 groups may be further substituted where appropriate; further wherein R 2 , R 3 , R 4 , and R 5 are the same or different and are selected from hydrogen, hydroxyl, alkyl, alkoxy, aryloxy, alkenyl, cycloalkyl, aryl, aralkyl, alkaryl, alkylamino, arylamino, heterocycle, acyl, aroyl, cyano, halogen, thiol, thioalkyl, thioaryl, amino, nitro, sulfonate, sulfone, sulfonamide, carboxylic acid, alkyl ester and, aryl ester, wherein the alkyl moieties in the R 2 , R 3 , R 4 , and R 5 groups may be linear or branched and each of the R 2 , R 3 , R 4 , and R 5 groups may be further substituted where appropriate. [0027] Effective quinonediimines for use in the invention include those represented by the following formulas IIIa and IIIb: [0028] wherein R 1 and R 2 are independently selected from hydrogen, hydroxyl, alkyl, alkoxy, aryloxy, alkenyl, cycloalkyl, aryl, aralkyl, alkaryl, alkylamino, arylamino, heterocycle, acyl, formyl, aroyl, cyano, halogen, thiol, alkylthio, arylthio, amino, nitro, sulfonate, alkyl sulfonyl, aryl sulfonyl, amino sulfonyl, hydroxy carbonyl, alkyloxycarbonyl and aryloxycarbonyl, wherein the alkyl moieties in the R 1 and R 2 groups may be linear or branched and each of the R 1 and R 2 groups may be further substituted; further wherein R 3 , R 4 , R 5 , and R 6 are the same or different and are selected from hydrogen, hydroxyl, alkyl, alkoxy, aryloxy, alkenyl, cycloalkyl, aryl, aralkyl, alkaryl, alkylamino, arylamino, heterocycle, acyl, aroyl, cyano, halogen, thiol, alkylthio, arylthio, amino, nitro, sulfonate, alkyl sulfonyl, aryl sulfonyl, aminosulfonyl, hydroxycarbonyl, alkyloxycarbonyl and aryloxycarbonyl, wherein the alkyl moieties in the R 3 , R 4 , R 5 , and R 6 groups may be linear or branched and each of the R 3 , R 4 , R 5 , and R 6 groups may be further substituted where appropriate. [0029] It is preferred that R 1 and R 2 are independently selected from alkyl, alkenyl, cycloalkyl, aryl, aralkyl and alkaryl for quinonediimines. [0030] It is preferred that the number of carbon atoms in any and all of the above R groups be from 0 to about 25. [0031] The most preferred surface treating agent is N-phenyl-N′-1, 3 dimethylbutyl-p-quinonediimine. [0032] Carbon black suitable for use in the invention has a preferred surface area of from about 9 to about 420 m 2 /g, and most preferred from about 40 to about 140 m 2 /g, as measured by the nitrogen adsorption method (ASTM D 4820). The carbon black may be agglomerated in the form of beads or powder. The carbon black types have a preferred particle size of from about 8 to about 300 nm average particle size and most preferably from about 12 to about 100 nm. [0033] The surface of the carbon black is preferably treated with from about 0.01 to about 150.0 parts by weight, most preferably from about 0.5 to about 8.0 parts by weight, of the surface treating agent per 100 parts by weight of carbon black. [0034] The surface treating agents may be combined with carbon black beads or powder by spraying the beads or powder with the surface treating agents at a temperature of from above the melting point of the surface treating agent to a temperature below its decomposition temperature. The combination may also be effected by dissolving the surface treating agent in an appropriate solvent and applying the resulting solution to the beads or powder followed by removal of the solvent to produce the surface treated carbon black. Appropriate solvents include but are not limited to a hexane, THF, toluene, benzene and methanol. [0035] For best results, the surface treating agents should be added to the carbon black at any point from the production site of the carbon black to prior to the mixing of the carbon black and surface treating agent combination with the polymeric material. Such treatment may occur at the entrance of the mixing device in which the carbon black and polymeric material are mixed. [0036] Without intending to be limited to any particular theory, we believe that the surface treated carbon black of our invention works in a very special way in polymer compositions that accounts for their superior effectiveness. There is some evidence indicating the surface treating agents are bound into the polymer structure of the rubber rather than just acting as a wetting agent which is the case with the anti-degradents of U.S. Pat. No. 4,764,547. [0037] To explain further, our carbon black surface treating agents contain a non-nucleophilic nitrogen and is an electron acceptor. As mentioned above, this is distinguished from the anti-degradents of U.S. Pat. No. 4,764,547 that contain nucleophilic nitrogen and are electron donors and/or hydrogen atom donors. Our surface treating agents react differently with radicals, i.e. by addition reactions with the radicals, the effect being an active rather than an inert surface treatment. This results not only in dispersion improvement, but also in the modification of the rheological and physical properties of a rubber compound. [0038] The natural or synthetic polymers used in accordance with the invention may be natural rubber (NR), a synthetic rubber such as isoprene rubber (IR) or a mixture thereof. Such polymers may be natural or synthetic elastomers, plastics, or blends thereof. Preferably, the rubber composition comprises NR. Blends of a polyisoprene rubber with one or more other rubbers such as polybutadiene rubber or butadiene rubber (BR), styrene-butadiene rubber (SBR), and a mixture of BR and SBR may also be used. [0039] In this application, the abbreviation “phr” means the number of parts by weight per 100 parts by weight of rubber. For example, in the case of a rubber blend, it would be based on 100 parts by weight of total rubber. “PhCB” means the number of parts by weight per 100 parts by weight of carbon black. [0040] A sulfur-vulcanizable rubber composition typically contains carbon black in an amount from about 10 to about 100, preferably about 20 to about 80, more preferably about 40 to about 80 phr. It may also contain silica in an amount of 0 to about 80, preferably 0 to about 60, more preferably 0 to about 50 phr. It may also contain a silane coupling agent for silica. The typical amount of the silane coupling agent employed is between about 5 to about 20% by weight of the silica loading. EXAMPLES [0041] The following examples illustrate the practice and benefits of our invention. [0042] Initially the surface treated carbon black product was evaluated using laboratory scale mixing equipment. This was followed by factory scale mixing experiments of NR and SBR tread formulations. [0043] The following surface treated products were prepared by directly spraying quinondiimines (in this case N-phenyl-N′-1,3 dimethylbutyl-p-quinonediimine (Compound A)) onto the surface of carbon black. [0044] For initial laboratory evaluations, a sample consisting of 4.4 PhCB of Compound A was used. Example 1 [0045] Laboratory Evaluation of Surface Treated Carbon Black in NR. [0046] The NR formulations used for initial evaluation are given in Table 1. TABLE I NR Tread Formulation for Lab. Evaluation of Surface Treated N-121 Carbon Black NR Surface Treated NR Control Carbon Black First Pass Mix Phr First Pass Mix Phr SMR CV60 1 100 SMR CV 60 100 N-121 2 50 N-121 (4.4 PhCB 52.2 Compound A) Zinc Oxide 4.0 Zinc Oxide 4.0 Stearic Acid 1.5 Stearic Acid 1.5 Microcrystalline 1.0 Microcrystalline 1.0 wax wax 6PPD 3 2.2 Total 158.7 Total 158.7 Final Mix Phr Final Mix Phr First Pass Mix 158.7 First Pass Mix 158.7 TBBS 4 1.6 TBBS 1.6 Sulfur 1.2 Sulfur 1.2 Total 161.5 Total 161.5 [0047] The degree of carbon black dispersion found for the first pass mixes are compared in Table 2 below. [0048] Dispersion analysis is carried out in accordance with ASTM D 2663-93 Test Method C, Annual Book of ASTM Standards, Vol., 09.01, Sect. 9, p. 468,1993, and is reported as dispersion index (DI). TABLE 2 Dispersion Index and Mooney Viscosity for NR Tread Compound N-121/ N-121 + COMPOUND COMPOUND N-121 + 6- A Surface Treated A Added in- PPD Added Product situ in-situ Property Treated Control Control Master batch Properties DI (Master batch) 91 77 77 Frequency (p/cm) 27 51 51 Height (micrometers) 2.4 2.3 2.3 F 2 H 1735 5872 5814 Compound Properties Mooney Viscosity M L 86 87 92 (1 + 4) 100 % Modulus (MPa) 3.3 3.7 3.6 [0049] The data in Table 2 shows that Compound A surface treated carbon black yields an improved dispersion index of 91, the control masterbatch that was mixed with 6-PPD (an amine as taught in the prior art) had a dispersion index of 77. The average height (H) of the peaks (undispersed carbon black) for all the samples was similar (about 2.3 micrometers). However, the frequency of peaks/cm (P/cm) was significantly lower for the Compound A surface treated carbon black (27 vs. 51). Hence F 2 H, which is used to calculate the dispersion index was also lower. The additional benefits observed were reductions in viscosity and modulus. A reduction in viscosity would make natural rubber easier to process, while a reduction in modulus would permit higher filler loading and hence potential material cost savings. [0050] With further regard to Table 2, “Added in-situ” means that the surface treating agent was added to the masterbatch rather than used to treat the carbon black. Example 2 [0051] Large Scale Evaluation of Surface Treated Black in NR. [0052] This carbon black treated with Compound A was then mixed in an 80 L internal mixer (Farrell model FT-80C) and compared to a compound prepared with the N-121 not treated with Compound A. The formulations used are given in Table 3 below. TABLE 3 NR Tread Formulations for Large Scale Evaluation of Surface Treated N-121 Carbon Black NR Surface Treated NR Control Black Master Batch Phr Masterbatch Phr SIR 10 5 100 SIR 10 100 N-121 50 N-121 (4.4 54 PhCB Compound A) Zinc Oxide 4 Zinc Oxide 4 Stearic Acid 1.5 Stearic Acid 1.5 Microcrystalline 1 Microcrystalline 1 wax wax Total 156.5 Total 160.5 Final Mix Phr Final Mix Phr Masterbatch 156.5 Masterbatch 160.5 TMQ 6 0.7 TMQ 0.7 TBBS 1 TBBS 1 Sulfur 2 Sulfur 2 6PPD 2 Total 162.2 Total 164.2 [0053] Ingredients for the ‘first mix’ were mixed with the rotor and wall temperature at 120° F., ram pressure at 60 PSI, and fill factor (volume % of the mixer that is filled) of 73%. The batches were mixed to a temperature of 350° F. as measured by a thermocouple located in the mixer. The batches were sheeted on a two-roll mill and allowed to cool. The average of three mixes each are reported below for the control black and the black treated with Compound A. [0054] As seen in Table 4 below, mixing times in the second stage are reduced ˜40-45% when the carbon black is treated with Compound A. Overall, total mixing times are reduced by 18 to 27% (first pass mix time plus second pass mix times). TABLE 4 Large Scale Mixing Characteristics of Surface Treated Carbon Black Product (AB) Master Batch (first mix) Final Mix (second mix) Rotor Dump Dump Rotor Dump Dump Speed Temp Time Speed Temp Time Dispersion Compound Rpm ° F. Seconds Rpm ° F. Seconds Index Control 70 358 127 26 225 187 70 AB 70 360 124 26 226 106 80 AB 52 357 152 26 217 106 83 [0055] The ‘first mixes’ were allowed to relax for at least 4 hours but not more than 48 hours then mixed again. The rotor and wall temperatures were set to 120° F., ram pressure @40 PSI, and the fill factor was 69%. The mixes were mixed to a temperature of 210° F. as measured by a thermocouple located in the mixing chamber. [0056] The above batches were cured in a rubber process analyzer (RPA model 2000) at 150° C. for 15 minutes. Dynamic mechanical properties were measured by a strain sweep having a frequency of 100 cycles per second. As expected, slight reductions in G′ (elastic component of shear modulus) occurred while greater reductions in G″ (viscous component of shear modulus) were observed. Averaging two mixes prepared as described above gave the reductions in loss tangent as a function of strain as shown in the following Table 5: [0057] The above batches were cured in a rubber process analyzer (RPA model 2000) at 150° C. for 15 minutes. Dynamic mechanical properties were measured by a strain sweep having a frequency of 100 cycles per second. As expected, slight reductions in G′ (elastic component of shear modulus) occurred while greater reductions in G″ (viscous component of shear modulus) were observed. Averaging two mixes prepared as described above gave the reductions in Loss Tangent (Tan D) as a function of strain as shown in the following Table 5: TABLE 5 RPA Dynamic Mechanical Properties Measured at 60° C. Percent Change in Control 70 RPM Surface Treated Carbon Black −70 Properties Average of two mixes RPM Average of two mixes Compared to Control % Strain G′ kPa G″ kPa Tan D G′ kPa G″ kPa Tan D G′ G″ Tan D 0.56 3223 244 0.0755 2745 182 0.0660 −14.8 −25.5 −12.6 0.98 2880 240 0.0833 2522 180 0.0715 −12.4 −25.0 −14.2 1.95 2499 266 0.1065 2235 202 0.0903 −10.6 −24.1 −15.2 5.02 2050 260 0.1269 1873 207 0.1105 −8.6 −20.4 −13.0 10.04 1799 252 0.1398 1669 204 0.1220 −7.2 −19.0 −12.7 24.97 1393 349 0.2504 1331 314 0.2362 −4.5 −9.8 −5.7 49.94 1122 337 0.3005 1080 318 0.2940 −3.7 −5.7 −2.2 [0058] Loss tangent is proportional to energy loss or hysteresis, is measured as the ratio of G″ (loss modulus, kilo Pascals) to G′ (storage modulus, kilo Pascals) and is termed loss tangent or Tan D. Tan D is proportional to rolling resistance and thus fuel efficiency of a tire compound. Compounds with a lower Tan D measured at 60° C. will have lower rolling resistance and thus be more fuel efficient. Example 3 [0059] Laboratory Scale Evaluation of an NR/BR (BR is butadiene rubber) Sidewall Compound. [0060] A sidewall recipe containing NR/BR in a 55/45 parts ratio and 50 phr of N550 carbon black was mixed on a laboratory scale and evaluated for physical properties and carbon black dispersion. The recipe is shown in table 6 below. The physical properties and dispersion information are shown in table 7. The batch mixed using the Compound A treated N550 exhibited an improvement in carbon black dispersion but not the reduction in viscosity or 100% modulus that was seen with the NR tread recipe. TABLE 6 NR/BR Sidewall Recipe for Laboratory Evaluation Compound A Treated N550 Carbon Black NR/BR Surface Treated NR/BR Control Black Master Batch Phr Master Batch phr SMR CV-60 55.0 SMR CV-60 55.0 Butadiene Rubber 45.0 Butadiene Rubber 45.0 N-550 50.0 N-550 (4.6 PhCB 52.3 6Compound A) Zinc oxide 3.0 Zinc oxide 3.0 Stearic acid 1.5 Stearic acid 1.5 6-PPD 2.3 6-PPD 0.0 Napthenic oil 10.0 Napthenic oil 10.0 Microcrystalline 2.0 Microcrystalline 2.0 wax wax Total 168.8 Total 168.8 Final Mix Phr Final Mix phr Master Batch 168.8 Master Batch 168.8 TBBS 1.0 TBBS 1.0 Sulfur 1.6 Sulfur 1.6 Total 171.4 Total 171.4 [0061] [0061] TABLE 7 Dispersion Index and Mooney Viscosity for NR/BR Sidewall Compound N550/COMPOUND A Additive N550 + 6-PPD Product Added in-situ Property Treated Control Masterbatch Properties DI (Masterbatch) 98.4 96.5 Frequency (p/cm) 27 47 Height (micrometers) 2.2 1.7 F 2 H 1604 3755 Compound Properties Mooney Viscosity 45 46 M L (1 + 4) 100% Modulus (MPa) 2.2 1.9 Example 4 [0062] Large Scale Evaluation of an SBR (styrene butadiene rubber) Tread Recipe [0063] The SBR recipe mixed and tested is detailed in Table 8 below. The batches were mixed to a first pass drop temperature of 350° F. using a fill factor of 69%. Rotor speeds were adjusted in order to produce a range of mix quality; i.e., to produce under mixed and over-mixed batches for comparison to properly mixed batches. The second pass mixes were dropped at 210° F. Mix cycle time, dispersion index, and Mooney viscosities were compared for each of the second pass mixes shown in Table 9 below. The second pass mix times were found to average ˜40-50% shorter mixing times for the batches containing the Compound A treated carbon black. This leads to approximately a 20% decrease in the overall mix cycle times (first pass plus second pass times). No difference was found in the dispersion index between the control compounds and the compounds containing the treated carbon black. However, very large differences were found for the Mooney viscosities of the compounds containing the treated carbon black and the control compounds. Unlike the case of the NR tread compound, the Mooney viscosities of the SBR compounds containing surface treated carbon black were significantly increased over those of the corresponding control batches. This indicates either that the Compound A treatment has promoted greater interaction between the polymer and the carbon black or that it has prevented significant breakdown of the polymer during the mixing process. In either case treadwear should be improved versus the control compound. TABLE 8 SBR Tread Compounds for Large Scale Evaluation of N-121 Surface Treated Carbon Black SBR Surface Treated SBR Control Carbon Black First Pass Mix Phr First Pass Mix Phr SBR 100 SBR 100 N-121 50 N-121 (4.4 52.2 Compound A) Zinc Oxide 3.0 Zinc Oxide 3.0 Stearic Acid 2 Stearic Acid 2 Aromatic oil 10 Aromatic oil 10 Microcrystalline 1.0 Microcrystalline 1.0 wax wax 166.0 168.2 Final Mix Phr Final Mix Phr First Pass Mix 166.0 First Pass Mix 168.2 TBSI 7 1.7 TBSI 1.7 TMTD 8 1.42 TMTD 1.42 Sulfur 2.07 Sulfur 2.07 6PPD 2.2 6PPD 0.0 173.39 173.39 [0064] [0064] TABLE 9 Mix Cycle and Dispersion Data for SBR Tread Compound Second Pass Master Batch Bound Initial ML Min. Mooney Rotor Dump Dump Rotor Dump Dump Rubber Mooney 1 + 4 @ 121° C. Speed Temp Time Speed Temp Time Dispersion Volume Vis. @ @ (Mooney Compound Rpm ° F. Seconds Rpm ° F. Seconds Index Fraction 121° C. 121° C. scorch test) Control 70 366 118 26 223 79 88.0 0.2480 121 88 88 52 362 170 26 223 89 93.0 0.2541 121 88 88 105 366 79 26 220 80 80.0 0.2540 120 89 88 Surface 70 368 98 26 201 48 85.0 0.4016 156 114 111 Treated 52 366 165 26 205 51 92.0 0.3775 153 106 103 Carbon 105 368 76 26 201 40 80.0 0.4018 170 127 121 Black

The invention comprises a composition comprising a combination of carbon black and at least one surface treating agent selected from the group consisting of quinone compounds, quinoneimine compounds and quinonediimine compounds, as well as methods of obtaining the composition and the use of the composition in dispersing carbon black in a natural or synthetic polymer. The composition achieves increased dispersibility and improved mixing characteristics of the carbon black and improved processability of the carbon black containing polymer.

FIELD OF THE INVENTION The present application is a divisional of U.S. application Ser. No. 09/874,979, filed Jun. 7, 2001, and now U.S. Pat. No. 6,846,140, which in turn claims benefit of priority U.S. Provisional Application Ser. No. 60/242,724, filed Oct. 25, 2000. The entire contents of both of these applications are incorporated herein by reference. The present invention relates generally to the field of trucks. More specifically, the present invention relates to a flexible tie-down system for trucks. BACKGROUND OF THE INVENTION The explosion in the popularity of pick-up trucks and/or sport utility trucks (SUTs) has fueled a proliferation of new body configurations. Trucks are offered as standard cabs, king cabs, crew cabs, SPORT TRACS, and the like. Likewise, truck interiors have been adapted to meet the needs for more comfort, more passenger capacity, and the like. One area of the pick-up truck that has yet to undergo a similar evolution is the cargo bed itself. It is ironic that the most utilitarian element of what is essentially a utilitarian vehicle is, in practical terms, not especially useful. As currently conceived, the standard full-sized pick-up bed is little more than a large empty volume with a few tie-down points scattered along the perimeter of its interior walls or along a bed rail. There is an enormous opportunity to improve the utility and ease of use of a truck bed. Some trucks are used primarily for work and others primarily for recreation. Many trucks do double-duty supporting both of these spheres of activity. One of the most glaring deficiencies of current bed design is that they are not readily adaptable to the wide variety of applications required by the end user. A truck bed should be able to support and accommodate the very different requirements that are associated with a diverse range of activities. Generally speaking, bed usage may be grouped into three broad categories: hauling, securing, and separating items in the payload. Most truck users need to perform each of these tasks with some frequency. Yet the demands placed on the bed for hauling are significantly different from those needed to secure or separate items in and around the bed. When hauling yard waste, plywood, recreational gear, and other items, the ideal condition is to maximize the interior volume of the bed and to maintain an easily accessible loading surface. When securing individual objects in the bed, such as dirt bikes, ATVs, air tanks, furniture, and other items, the ideal condition is to have multiple sturdy tie-down points in close proximity to the object being secured. When hauling and securing combinations of items—heavy objects and fragile equipment, for example—it becomes necessary to separate these items from one another. This situation has led to a brisk business in after-market systems created by after-market manufacturers. However, while many of these systems are at least partially effective, they are not necessarily designed to interface with the truck in an optimum manner from a functional, structural, and aesthetic standpoint. SUMMARY OF THE INVENTION An object of the invention is to provide a truly flexible cargo bed tie-down system that allows the user to easily change, adjust, customize, and adapt his or her vehicle to specific needs at any given moment, and that interfaces with the rest of the truck in an optimum manner from a functional, structural, and aesthetic standpoint. One embodiment of the invention provides a vehicle comprising a side wall construction enclosing a cargo bed at a side of the cargo bed. The side wall construction includes an outer portion which runs generally vertically at an outer portion of the vehicle, and a top portion which runs generally horizontally from the outer portion toward a longitudinal center of the vehicle. A tie-down rail is mounted adjacent to the top portion such that a part of the top portion overhangs at least a portion of the tie-down rail. The tie-down rail is configured to accept a tie-down fitting and includes a slotted opening generally aligned with an interior edge of the top portion. This permits tie-down rail(s) (also called track(s)) to blend in with the truck, which improves functionality. This is in contrast to currently available after-market products. Such after-market products and existing trucks are not necessarily designed to interface in an optimum manner, from a functional, structural and aesthetic standpoint. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in further detail below in conjunction with the following drawings: FIG. 1 is an end view of a truck embodying the invention. FIG. 2 is a sectional view of plane 2 - 2 of FIG. 1 . FIG. 3 is a sectional view of plane 3 - 3 of FIG. 1 . FIG. 4 is a sectional view of plain 4 - 4 of FIG. 1 (with a tie-down fitting installed). FIG. 5 illustrates an example of a tie-down fitting. FIG. 6 illustrates another example of a tie-down fitting. FIG. 7 illustrates an example of a tire cradle. FIG. 8 illustrates an example of a tank fitting. FIG. 9 illustrates an example of a cargo net arrangement. FIG. 10 illustrates an example of a cargo divider. FIG. 11 illustrates an example of a foldable storage box in a stored position. FIG. 12 illustrates the foldable storage box being placed in the storage position. FIG. 13 illustrates the foldable storage box in the storage position. FIGS. 14 through 17 illustrate an example of a tailgate extender, having a track, in four different positions. FIG. 18 illustrates an example of an arrangement of crossbar members. FIG. 19 illustrates an example of a pulley arrangement supported by the crossbar members. FIG. 20 illustrates one possible configuration of a track and fittings on a crossbar member. FIG. 21 illustrates a sectional view of plane 21 - 21 of FIG. 20 . FIG. 22 illustrates an example of a storage box for storing tie-down fittings and/or other items. FIG. 23 is a sectional view of the storage box of FIG. 22 . FIG. 24 is an example of another arrangement of tracks, according to the invention. FIG. 25 is an example of another arrangement of a track, according to the invention. FIG. 26 is an example of another arrangement of tracks, according to the invention. FIGS. 27 through 31 illustrate a type of fitting that may be used according to the invention. FIGS. 32 through 34 illustrate another type of fitting that may be used according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 illustrates an end view of a truck 100 configured in accordance with one embodiment of the invention. As shown in FIG. 1 , the truck 100 has a cargo bed, or area, 110 behind a cab (or passenger compartment) 120 . There are two sidewalls 122 , 124 on the sides of bed 110 and front wall 125 . In this particular configuration, the truck 100 also includes a tailgate 130 . Tracks 141 and 142 are located in bed 110 . The left sidewall 122 has a track 143 which opens inward and another track 144 which opens upward. Similarly, sidewall 124 has an inward facing track 145 and an upward facing track 146 . A rearward facing track 147 is located on front wall 125 behind cab 120 , and the free end of tailgate 130 includes a track 148 . FIG. 2 is a sectional view of plane 2 - 2 of FIG. 1 . FIG. 2 illustrates track 141 recessed in bed 110 . The track 141 is in the shape of a channel and has two inward turning lips 141 A and 141 B. The track 141 is provided with a slot opening S. The design of track 142 (with respect to bed 110 ) is similar to the design of track 141 . FIG. 3 is a sectional view of plane 3 - 3 of FIG. 1 . As shown in FIG. 3 , track 148 is located on the free end of tailgate 130 . Track 148 has inward turning lips 148 A and 148 B and a slot opening S. FIG. 4 is a sectional view of plane 4 - 4 of FIG. 1 , with a tie-down fitting installed. As illustrated, track 145 faces inward and track 146 faces upward. The design of tracks 145 and 146 is similar to the design of tracks 141 and 148 , as discussed above. Similarly, tracks 143 and 144 are similar to tracks 145 and 146 . An important feature of the invention is that the tracks are outside of the passenger compartment (in the FIG. 1 embodiment the tracks are behind the passenger compartment). This allows the storage of larger, heavier loads. Another important feature of the invention is that the tracks 141 to 148 are integral with the body of truck 100 such that the exterior contours of the tracks do not extend appreciably beyond the contour of adjacent portions of the body (e.g., not more than ⅛, ¼, ½, or ¾ inch beyond the contour of adjacent portions of the body). For example, the exterior contour of track 141 is flush with cargo bed 110 . In FIG. 3 , the upper horizontal surface of track 148 is flush with the uppermost portion 132 of tailgate 130 and the surface 148 C of track 148 is flush with the surface 134 of tailgate 130 . Similarly, as shown in FIG. 4 , the exterior contours of tracks 145 and 146 do not extend appreciably beyond the contour of adjacent portions of the body. This design permits the tracks to blend in with the body of the truck, which improves functionality because the tracks do not obstruct placement of items into or on the truck. Also, in the invention, the portions of the body of the truck that support the tracks are specifically designed to accommodate the tracks and to take large loads, which thus allows the tracks to support or secure large loads. As discussed above, this is in contrast to currently available after-market products which sit on top of the body of the truck. Such after-market products and existing trucks may not necessarily be designed to accommodate each other in an optimum manner, from a structural viewpoint. The contour of the adjacent portions of the body of the truck can be formed by, for example, structural steel, aluminum and other material that forms part of the structural part of the body, sheet metal, sheet aluminum or other material, and/or plastic (either separate or with a track encapsulated). The track slots can be pointed in any direction, for example, upward, downward, outboard, inboard, rearward, forward, or at an angle. Also, when the tracks are not in use, the tracks can be covered with a protective strip of, for example, rubber or plastic, which fits into the slot opening. In this particular embodiment of the invention, the geometry of the tracks is similar to the geometry of channels manufactured for industrial framing applications (for example for supporting pipes and electrical lines). This allows a user to employ a wide variety of commercially available fittings to customize and adapt the tie-down arrangement to the particular task at hand. FIGS. 4 and 5 illustrate an example of a tie-down fitting 210 . Fitting 210 may be used with rope, straps, and the like to secure items in and/or to the bed. This fitting 210 has three separate parts, a nut 212 available from (for example) the manufacturers listed below, a male threaded commercially available eye 214 , and a washer 216 . The nut has two grooves 212 A and 212 B that are intended to mate with the in-turned lips of the track (such as lips 145 A and 145 B of track 145 ). In this embodiment, washer 216 has a metal portion 216 A and an elastic portion 216 B. This fitting can be moved anywhere along a track and then fixed in a desired location. The fitting can also be released from the track, for example, by twisting or unscrewing the fitting and then removing the fitting in a direction approximately perpendicular to the track. Providing fittings that can be inserted anywhere along the track and that are movable within the track allows the user to customize and adapt the truck to the task at hand by providing the appropriate number and spacing of fittings required for the task at hand. Also, because the fittings are releasable, they can be removed when not needed, so that they do not become an obstruction. To use the assembly, the nut 212 is placed into the channel (or track), the washer 216 is placed on a threaded part of the eye 214 , and then the nut 212 is turned 90 degrees such that the grooves 212 A, 212 B in the nut mate with the in-turned lips 145 A and 145 B of the channel. Then, the eye is screwed into the nut until tight. This squeezes the track between the nut and the washer/eye assembly. The pressure locks the entire assembly to the track. The fitting is removed by loosening the nut/eye assembly, and turning the nut 90 degrees. FIG. 6 illustrates another example of a tie-down fitting 310 . This fitting 310 can be used for securing a wide variety of items to a track. As shown in FIG. 6 , fitting 310 includes a commercially available nut 312 , a knob portion 314 , a plastic or steel washer 315 , and a washer 316 . A contact portion 314 A of knob 314 is designed to hold an object between contact portion 314 A (and washer 315 ) and a track. The washer 316 is bonded to the nut 312 and rests on top of the track to keep the nut from falling into the track. An example of use of such a fitting will be described in further detail below in conjunction with FIGS. 10 , 20 and 21 . FIG. 7 illustrates an example of a specialized fitting 400 having a tire cradle 410 for use with the track system described above. This fitting 400 can be positioned and then secured, for example, to track 147 on front wall 125 behind the cab using fittings 420 and 430 . Fittings 420 and 430 are similar to fitting 210 , described above. Two straps 411 and 413 are used to secure a tire within the cradle 410 . This tire cradle can be used with the other fittings described in this patent specification to provide numerous tie-down points to stabilize, for example, a mountain bike or motorcycle, within the cargo bed. It will be appreciated that the fittings described in this patent specification can be used in conjunction with, for example, ropes, straps, rubber tie-downs, and the like, to secure objects to tie-down points throughout the cargo bed. FIG. 8 illustrates an example of a tank fitting 510 for use, for example, with the side tracks described above. Fitting 510 includes two commercially available bands 512 and 514 which are approximately in the shape of a quarter circle. The bands are joined at one end by a tightening assembly, such as a threaded knob 516 . The other ends of the bands are shaped to lie within one of the tracks (for example, track 145 , as shown in FIG. 8 ). Such fittings allow adjustable and secure placement of, for example, scuba tanks, and the like, near the bed perimeter. FIG. 9 illustrates an example of a cargo net arrangement 600 . Arrangement 600 includes a cargo net 610 which is secured to tracks 141 , 142 , and 148 using fittings 622 , 624 , 626 , and 628 . Fittings 622 , 624 , 626 , and 628 are similar to fitting 210 , shown in FIG. 5 . The tracks at the side of the bed and/or the tracks at the bottom of the bed, can also be used to secure a cargo divider, as shown in FIG. 10 . FIG. 10 illustrates a cargo divider 710 secured to tracks 141 , 142 , 144 , and 146 using fittings 722 , 724 , 726 , and 728 . Fittings 722 , 724 , 726 , and 728 are similar to fitting 310 , shown in FIG. 6 . FIGS. 11 to 13 depict a folding/stowable box arrangement 800 which is provided by the invention. FIG. 11 illustrates an example of the box in the storage position. When not in use, a lid 810 of the box and a rear side 820 of the box are folded together and are stored flat against the front wall 125 of the cargo bed to maximize bed space, as shown in FIG. 11 (in FIG. 11 , the lid 810 is hidden behind the side 820 ). When the user desires to place the box in the storage position, both the lid 810 and the rear side 820 are moved rearward using fittings 822 and 826 to guide the side 820 and maintain the side 820 approximately perpendicular to the cargo bed. Then, knobs 824 and 828 are tightened to secure fittings 822 and 826 to tracks 145 and 143 . Then, lid 810 , which is stored in slots 821 of side 820 (lid 810 is not shown in FIG. 12 in order to show slot 821 clearly), is pivoted, for example by a hinge, to cover the interior of the box, as shown in FIG. 13 . FIGS. 14 through 17 illustrate an example of a tailgate extender 900 , having a crossbar member 948 , in four different positions. As shown in these figures, the tailgate 130 is positionable such that the primary plane of the tailgate 130 is either vertical ( FIG. 14 ) or horizontal ( FIGS. 15 to 17 ). Crossbar member 948 runs in a direction perpendicular to the longitudinal direction of the truck. A first member 952 and a second member 954 are connected to the crossbar member 948 . The first member 952 , the second member 954 , and the crossbar member 948 lie in the same plane. A connection assembly (to be described below) connects the crossbar member 948 to the tailgate 130 via at least the first and second members 952 and 954 such that: (1) the first member 952 , the second member 954 , and the crossbar member 948 lie in the primary plane of the tailgate 130 to act as an upright for loads when the tailgate 130 is vertical (as shown in FIG. 14 ); (2) the first member 952 , the second member 954 , and the crossbar member 948 lie in the primary plane of the tailgate 130 to act as an extension of the tailgate 130 for longer loads when the tailgate 130 is horizontal (as shown in FIG. 15 ); (3) the first member 952 , the second member 954 , and the crossbar member 948 lie in a plane perpendicular to the primary plane of the tailgate 130 to act as an upright (or rear support) when the tailgate is horizontal (as shown in FIG. 16 ); or (4) the first member 952 , the second member 954 , and the crossbar member 948 lie in a plane perpendicular to the primary plane of the tailgate 130 to act as a step when the tailgate 130 is horizontal (as shown in FIG. 17 ). (Also, the tailgate extender can be positioned as shown in FIG. 17 , except with the tailgate closed, to provide another configuration, for example, for storing long objects.) The first and second members 952 and 954 can be stored within the tailgate 130 by pushing them into the tailgate (in which case the crossbar member 948 simply acts as a track on the free end of the tailgate similar to track 148 in FIG. 1 ). The first and second members 952 and 954 are secured to the tailgate 130 in one of the three relative positions by: (1) sliding the first and second members 952 and 954 into one pair of holes 962 and 964 which are parallel to the primary plane of the tailgate and securing the members by pins 932 and 934 ; or (2) sliding the first and second members 952 and 954 into one pair of holes 961 and 963 which are perpendicular to the primary plane of the tailgate 130 and securing the members by pins 932 and 934 . Pins 932 and 934 go through holes in tailgate 130 and members 952 and 954 . FIGS. 18 and 19 illustrate an example of an arrangement 1000 of crossbar members 1100 and 1200 that can be used to support, for example, ladders, plastic pipe, a large sea kayak, and other long objects. These crossbar members allow the cargo bed 1010 to be free for other gear. In addition, the longitudinal spacing of the crossbar members 1100 and 1200 can be adjusted to secure tall objects (such as appliances) between the crossbar members. (One way of securing such crossbar members to the tracks will be described below in connection with FIGS. 20 and 21 .) The crossbar members 1100 and 1200 can support, for example, a beam 1310 that can be cantilevered near the rear end of the truck to support a pulley system 1320 . FIG. 19 illustrates an example of pulley system 1320 being employed to easily load a heavy, awkwardly-sized object (wheel W) into the cargo bed 1010 . In one variation, upward facing tracks 144 and 146 may be eliminated and crossbar members 1100 and 1200 are secured to inward facing tracks 143 and 145 . FIG. 20 illustrates one possible configuration of a track 1410 and fittings 1420 , 1430 , and 1440 on a crossbar member 1400 . Fittings 1420 , 1430 , and 1440 are commercially available from various industrial framing manufacturers (listed below). As described above, one of the advantages of the invention is that a vehicle owner may use a wide variety of readily available fittings, in conjunction with the track system, to customize his or her truck and adapt the truck to the owner's particular requirements at hand. It will be appreciated that other types of fittings, which include additional tracks, can be provided. FIG. 21 illustrates a sectional view of plane 21 - 21 of FIG. 20 . As shown in FIG. 21 , crossbar member 1400 is secured to track 144 by securing a horizontal portion 1450 of crossbar member 1400 to the track using a knob fitting 1460 and a nut 1470 . A suitable design for such a fitting is illustrated in FIG. 6 . FIGS. 22 and 23 illustrate an example of a storage box 1500 in an outer side panel of a truck for storing fittings and/or other items. The box 1500 is supported by a slide 1510 . FIG. 24 is an example of another arrangement 1600 of tracks, according to the invention. As illustrated in FIG. 24 , arrangement 1600 includes tracks 1610 , 1620 , 1640 , and 1650 mounted to the inner sidewall of a cargo bed 1680 such that the exterior contours of these tracks do not extend appreciably beyond the contour of the adjacent portions of the body. Similarly, track 1630 is mounted to the front wall of cargo bed 1680 such that the exterior contours of the track do not extend appreciably beyond the contour of the adjacent portions of the body. FIG. 24 also illustrates tracks 1660 and 1670 which project approximately one inch above cargo bed 1680 . Thus, tracks 1660 and 1670 do extend appreciably beyond the contour of adjacent portions of the body. FIG. 24 illustrates that tracks according to the invention (tracks 1610 , 1620 , 1630 , 1640 , and 1650 ) may be mounted on the same vehicle which also has tracks ( 1660 and 1670 ) which do extend appreciably beyond the contour of the adjacent portions of the body. FIG. 25 is an example of another arrangement 1700 of a track 1710 , according to the invention, that does not extend appreciably beyond the contour of adjacent portions 1720 of the body. FIG. 26 is another example of another arrangement of tracks 1800 , according to the invention. As shown in FIG. 26 , the arrangement includes a number of body panels, 1810 , 1820 , 1830 , 1840 , and 1850 . The body panels are joined, for example, by fasteners 1862 , 1864 , and 1866 . Tracks 1872 and 1874 are mounted to the body panels by, for example, welds 1871 , 1873 , 1875 , and 1877 . The tracks can be connected to the body by other means, such as bolts. As shown in FIG. 26 , the tracks 1872 and 1874 are mounted to the panels such that the exterior contours of tracks 1872 and 1874 do not extend appreciably beyond the adjacent portions of the body. In the most preferred embodiment, the exterior contours of the tracks are substantially flush with the adjacent portions of the body. However, the exterior contours of the track can extend up to one-eighth of an inch beyond the adjacent portions of the body, one-quarter of an inch beyond the contour of the adjacent portions of the body, or up to one-half of an inch beyond the contour of the adjacent portions of the body. FIGS. 27 to 31 illustrate another type of fitting 1900 that may be used. If the fittings described above in connection with FIGS. 5 and 6 are not tightened enough or if the eye (or knob) is turned, the assembly can loosen and may fall out of the track. On the other hand, if the fitting is tightened too tightly, especially in the case of an aluminum track, there could be damage or premature wear of the track. The FIG. 27-31 embodiment provides a more positive engagement with the track that does not rely as much on the user having the correct “feel” in tightening the thread/nut assembly. In this embodiment, the tie-down fitting does not clamp onto the track, but instead stays in place by a combination of a pin and a lock bar. As will be described below, this embodiment of the invention requires holes in the back side of the track(s). As shown in the Figures, there are four major pieces to this design. A center shaft 1910 is provided with an eye 1920 (or other type of fitting/connection) on one end, a square shank 1930 in the middle, and a pin 1940 on the other end. Eye 1920 , shank 1930 , and pin 1940 are formed together as one piece. A rectangular lock bar 1950 is provided with a hole the same diameter as the pin end 1940 of the center shaft 1910 . A spring locking ring 1960 has a square hole to match the shank 1930 of the center shaft and includes a recessed area which houses an internal spring 1968 , notches for fingers, and a boss 1962 to engage the track opening. A set screw 1952 , or pin, secures the lock bar 1950 to the center shaft. In this particular configuration, a link 1922 is attached to the eye 1920 of the center shaft. To assemble the unit, the spring 1968 is slid onto the center shaft 1910 stopping against a larger diameter near the eye end. The locking ring 1960 is then slid over the square shank 1930 of the center shaft 1910 . Then, the lock bar 1950 is installed over the center shaft pin 1940 , and is aligned so that the long side of the lock bar 1950 is perpendicular to a long side of the locking ring boss 1962 and is screwed (or pinned) in place by screw 1952 . To install the fitting 1900 , the entire unit is positioned in a track 2020 , opposite a track hole 2010 , with the lock bar 1950 aligned with the track, as shown in FIG. 29 . The center shaft 1910 is pushed to overcome the spring pressure, allowing the lock bar 1950 to pass the sides of the track opening. Then, the entire unit is rotated until the boss 1962 on the locking ring 1960 aligns with the track opening and the spring forces the locking ring 1960 down against the track, as shown in FIG. 30 . This also causes the lock bar 1950 to be wedged in between the back of track 2020 and track lips 2022 and 2024 (this keeps the pin 1940 engaged in the hole 2010 and keeps the entire assembly from pulling out of the track). To remove, the thumb pushes down on the center shaft 1910 and fingers on either side of the locking ring 1960 lift the locking ring 1960 and boss 1962 away from the track opening, as shown in FIG. 31 . The entire unit is then rotated 90 degrees, allowing the locking bar 1950 to disengage from the track. This embodiment thus provides an arrangement that is simple, easy to use, and provides very positive locking action. As long as the boss 1962 holds the lock bar 1950 from rotating, the only way to move or remove the tie-down fitting would require destruction or gross distortion of the track and/or tie-down fitting. FIGS. 32 through 34 illustrate another type of fitting that may be used according to the invention. This type of fitting also requires tracks with holes. In this embodiment, the assembly 2100 includes a loop 2110 welded to a pin 2120 after the pin is inserted through a plastic (or metal) spring 2130 and spacer 2140 , which in turn is mechanically bonded to a rectangular metal locking bar 2150 . This arrangement allows the loop/pin assembly to spin freely with respect to spring 2130 , spacer 2140 , and locking bar 2150 at all times. A projection 2122 on the bottom of pin 2120 and a projection on the top of pin 2120 (not visible in the drawings) maintain spring 2130 , spacer 2140 , and bar 2150 on the pin (while still allowing relative rotation therebetween). To use this fitting 2100 , the fitting is positioned over the track 2220 above a track hole 2210 , as shown in FIG. 33 . The pin 2120 is inserted into the hole 2210 , with the rectangular locking bar 2150 positioned to drop into the track. The spring 2130 (and therefore the locking bar 1950 ) is then twisted 90 degrees clockwise until detents 2132 and 2134 on the underside of the spring drop into the track, as shown in FIG. 34 . The tension between spring 2130 and locking bar 2150 on the track 2220 maintain the assembly in this position. To remove this tie-down, the spring 2130 (and the locking bar 2150 ) is rotated counter-clockwise. Numerous other types of fittings may be used with the invention, for example, supports for plate glass racks, supports for ladders, and the like. Suitable off-the-shelf fittings are readily available for strut systems and are offered by, for example, Unistrut (Wayne, Mich.); Midland-Ross Corp., Superstrut Division, (Oakland, Calif.); and B-Line Systems, Inc. (Highland, Ill.). The invention is not limited to the preferred embodiments described above. For example, a track could be mounted directly to the tailgate without the use of members 952 and 954 . Variations and modifications of the invention will occur to those in the field, in light of the above teachings. The invention is therefore defined by reference to the following claims.

A flexible cargo bed tie-down system allows the user to easily change, adjust, customize, and adapt his or her vehicle to specific needs at any given moment, and interfaces with the rest of the vehicle in an optimum manner from a functional, structural, and aesthetic standpoint. One embodiment of the invention provides a vehicle having a side wall construction enclosing a cargo bed at a side of the cargo bed. The side wall construction includes an outer portion which runs generally vertically at an outer portion of the vehicle, and a top portion which runs generally horizontally from the outer portion toward a longitudinal center of the vehicle. A tie-down rail is mounted adjacent to the top portion such that a part of the top portion overhangs at least a portion of the tie-down rail. The tie-down rail is configured to accept a tie-down fitting and includes a slotted opening generally aligned with an interior edge of the top portion.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to compounds which are useful as therapeutic agents. Among other potential uses, these compounds are believed to have properties which are characteristic of prostaglandins. 2. Description of Related Art Ocular hypotensive agents are useful in the treatment of a number of various ocular hypertensive conditions, such as post-surgical and post-laser trabeculectomy ocular hypertensive episodes, glaucoma, and as presurgical adjuncts. Glaucoma is a disease of the eye characterized by increased intraocular pressure. On the basis of its etiology, glaucoma has been classified as primary or secondary. For example, primary glaucoma in adults (congenital glaucoma) may be either open-angle or acute or chronic angle-closure. Secondary glaucoma results from pre-existing ocular diseases such as uveitis, intraocular tumor or an enlarged cataract. The underlying causes of primary glaucoma are not yet known. The increased intraocular tension is due to the obstruction of aqueous humor outflow. In chronic open-angle glaucoma, the anterior chamber and its anatomic structures appear normal, but drainage of the aqueous humor is impeded. In acute or chronic angle-closure glaucoma, the anterior chamber is shallow, the filtration angle is narrowed, and the iris may obstruct the trabecular meshwork at the entrance of the canal of Schlemm. Dilation of the pupil may push the root of the iris forward against the angle, and may produce pupilary block and thus precipitate an acute attack. Eyes with narrow anterior chamber angles are predisposed to acute angle-closure glaucoma attacks of various degrees of severity. Secondary glaucoma is caused by any interference with the flow of aqueous humor from the posterior chamber into the anterior chamber and subsequently, into the canal of Schlemm. Inflammatory disease of the anterior segment may prevent aqueous escape by causing complete posterior synechia in iris bombe, and may plug the drainage channel with exudates. Other common causes are intraocular tumors, enlarged cataracts, central retinal vein occlusion, trauma to the eye, operative procedures and intraocular hemorrhage. Considering all types together, glaucoma occurs in about 2% of all persons over the age of 40 and may be asymptotic for years before progressing to rapid loss of vision. In cases where surgery is not indicated, topical β-adrenoreceptor antagonists have traditionally been the drugs of choice for treating glaucoma. Certain eicosanoids and their derivatives have been reported to possess ocular hypotensive activity, and have been recommended for use in glaucoma management. Eicosanoids and derivatives include numerous biologically important compounds such as prostaglandins and their derivatives. Prostaglandins can be described as derivatives of prostanoic acid which have the following structural formula: Various types of prostaglandins are known, depending on the structure and substituents carried on the alicyclic ring of the prostanoic acid skeleton. Further classification is based on the number of unsaturated bonds in the side chain indicated by numerical subscripts after the generic type of prostaglandin [e.g. prostaglandin E 1 (PGE 1 ), prostaglandin E 2 (PGE 2 )], and on the configuration of the substituents on the alicyclic ring indicated by α or β [e.g. prostaglandin F 2α (PGF 2β )]. Prostaglandins were earlier regarded as potent ocular hypertensives, however, evidence accumulated in the last decade shows that some prostaglandins are highly effective ocular hypotensive agents, and are ideally suited for the long-term medical management of glaucoma (see, for example, Bito, L. Z. Biological Protection with Prostaglandins , Cohen, M. M., ed., Boca Raton, Fla., CRC Press Inc., 1985, pp. 231-252; and Bito, L. Z., Applied Pharmacology in the Medical Treatment of Glaucomas Drance, S. M. and Neufeld, A. H. eds., New York, Grune & Stratton, 1984, pp. 477-505. Such prostaglandins include PGF 2α , PGF 1α , PGE 2 , and certain lipid-soluble esters, such as C 1 to C 2 alkyl esters, e.g. 1-isopropyl ester, of such compounds. Although the precise mechanism is not yet known experimental results indicate that the prostaglandin-induced reduction in intraocular pressure results from increased uveoscleral outflow [Nilsson et. al., Invest. Ophthalmol. Vis. Sci . (suppl), 284 (1987)]. The isopropyl ester of PGF 2α has been shown to have significantly greater hypotensive potency than the parent compound, presumably as a result of its more effective penetration through the cornea. In 1987, this compound was described as “the most potent ocular hypotensive agent ever reported” [see, for example, Bito, L. Z., Arch. Ophthalmol. 105 1036 (1987), and Siebold et al., Prodrug 5 3 (1989)]. Whereas prostaglandins appear to be devoid of significant intraocular side effects, ocular surface (conjunctival) hyperemia and foreign-body sensation have been consistently associated with the topical ocular use of such compounds, in particular PGF 2α and its prodrugs, e.g., its 1-isopropyl ester, in humans. The clinical potentials of prostaglandins in the management of conditions associated with increased ocular pressure, e.g. glaucoma are greatly limited by these side effects. In a series of United States patents assigned to Allergan, Inc. prostaglandin esters with increased ocular hypotensive activity accompanied with no or substantially reduced side-effects are disclosed. Some representative examples are U.S. Pat. Nos. 5,446,041, 4,994,274, 5,028,624 and 5,034,413 all of which are hereby expressly incorporated by reference. GB 1,601,994 discloses compounds having the formula shown below in which A represents a CH═CH group; B represents a-CH2—CH2—, trans-CH═CH— or —C≡C— group, W represents a free, esterified or etherified hydroxymethylene group, wherein the hydroxy or esterified or etherified hydroxy group is in the- or A-configuration, . . . or W represents a free or ketalised carbonyl group, D and E together represent a direct bond, or D represents an alkylene group having from 1 to 5 carbon atoms or a —C≡C— group, and E represents an oxygen or sulphur atom or a direct bond, R 3 represents an aliphatic hydrocarbon radical, preferably an alkyl group, which may be unsubstituted or substituted by a cycloalkyl, alkyl substituted cycloalkyl, unsubstituted or substituted aryl or heterocyclic group, a cycloalkyl or alkyl-substituted cycloalkyl group, or an unsubstituted or substituted aryl or heterocyclic group, e.g. a benzodioxol-2-yl group, and Z represents a free or ketalised carbonyl group or a free esterified or etherified hydroxymethylene group in which the free, esterified or etherified hydroxy group may be in the α- or β-configuration. JP 53135955 discloses several compounds such as the one shown below. DE 2719244 discloses several compounds such as the ones shown below. For the top compound (I), R=H, C 1-4 alkyl, or H 2 HC(CH 2 OH) 3 ; R 1 , R 2 =H or Me; and R 3 =a heterocycle (often substituted). U.S. Pat. No. 4,055,602 discloses several compounds such as the one shown below, wherein n=2-4; R=H or OH; R 1 , R 2 =H, F, Me; and Ar=aryl. The '602 patent also discloses the compound shown below, and others like it. DE 2626888 discloses several compounds such as the one shown below. Other references, such as U.S. Pat. No. 4,119,727, disclose similar compounds. BRIEF DESCRIPTION OF THE INVENTION A compound comprising or a pharmaceutically acceptable salt or a prodrug thereof, wherein a dashed line represents the presence or absence of a bond; A is —(CH 2 ) 6 —, or cis —CH 2 —CH═CH—(CH 2 ) 3 —, wherein 1 or 2 carbons may be substituted with S or O; B is hydrogen, —CH 3 , or ═CH 2 ; J is —OH or ═O; D is —(CH 2 ) n —, —X(CH 2 ) n , or —(CH 2 ) n X—, wherein n is from 0 to 3 and X is S or O; and E is an aromatic or heteroaromatic moiety, or a substituted aromatic or heteroaromatic moiety having substituents comprising from 1 to 6 non-hydrogen atoms each, is disclosed herein. Also disclosed herein are compounds having an α and an ω chain comprising or a derivative thereof, wherein B is hydrogen, —CH 3 or ═CH 2 , and a dashed line represents the presence or absence of a bond; wherein said derivative has a structure as shown above except that 1 or 2 alterations are made to the α chain and/or the ω chain, and wherein an alteration consists of: a. adding, removing, or substituting a non-hydrogen atom, or b. changing the bond order of an existing covalent bond without adding or deleting said bond; or a pharmaceutically acceptable salt, a tetrazole, or a prodrug thereof. Also disclosed herein are methods of treating diseases or conditions, including glaucoma and elevated intraocular pressure. Compositions and methods of manufacturing medicaments related thereto are also disclosed. BRIEF DESCRIPTION OF THE DRAWING FIGURES FIGS. 1-2 illustrate one method of preparing the compounds disclosed herein. DETAILED DESCRIPTION OF THE INVENTION Several of the carbon atoms on these compounds are chiral centers. While not intending to limit the scope of the invention in any way, or be bound in any way by theory, it is believed that many compounds and pharmaceutically active salts or prodrugs thereof having the stereochemistry shown below are particularly useful. However, it is also advantageous if one or more of the bonds has the indicated stereochemistry, while the stereochemistry of other bond to chiral centers may vary. Thus, while not intending to limit the scope of the invention in any way, compounds comprising and the like, and pharmaceutically acceptable salts and prodrugs thereof, are particularly useful in the context disclosed herein. A person of ordinary skill in the art understands the meaning of the stereochemistry associated with the hatched wedge/solid wedge structural features. For example, an introductory organic chemistry textbook (Francis A. Carey, Organic Chemistry, New York: McGraw-Hill Book Company 1987, p. 63) states “a wedge indicates a bond coming from the plane of the paper toward the viewer” and the hatched wedge, indicated as a “dashed line”, “represents a bond receding from the viewer.” In relation to the identity of A disclosed in the chemical structures presented herein, in the broadest sense, A is —(CH 2 ) 6 —, or cis —CH 2 CH═CH—(CH 2 ) 3 —, wherein 1 or 2 carbons may be substituted with S or O. In other words, A may be —(CH 2 ) 6 —, cis —CH 2 CH═CH—(CH 2 ) 3 —, or A may be a group which is related to one of these two moieties in that any carbon is substituted with S or O. For example, while not intending to limit the scope of the invention in any way, A may be an S substituted moiety such as one of the following or the like. Alternatively, while not intending to limit the scope of the invention in any way, A may be an O substituted moiety such as one of the following or the like. In other embodiments, A is —(CH 2 ) 6 —or cis-CH 2 CH═CH—(CH 2 ) 3 — having no heteroatom substitution. Since B can be hydrogen, methyl (—CH 3 ), or methylene (═CH 2 ), compounds of the structures shown below are possible. Pharmaceutically acceptable salts or prodrugs of these compounds are also useful. Since J can be —OH or ═O, compounds of the structures shown below, and pharmaceutically acceptable salts or prodrugs thereof, are possible. In relation to the identity of D, D is —(CH 2 ) n —, —X(CH 2 ) n , or —(CH 2 ) n X—, wherein n is from 0 to 3 and X is S or O. In other words, while not intending to be limiting, D may be a bond, —CH 2 —, —CH 2 CH 2 —, —CH 2 CH 2 CH 2 —, S, O, —SCH 2 —, —SCH 2 CH 2 —, —SCH 2 CH 2 CH 2 —, —CH 2 S—, —CH 2 CH 2 S—, —CH 2 CH 2 CH 2 S—, —OCH 2 —, —OCH 2 CH 2 —, —OCH 2 CH 2 CH 2 —, —CH 2 O—, —CH 2 CH 2 O—, or —CH 2 CH 2 CH 2 O—. A person of ordinary skill in the art will understand that n is required to be an integer. In relation to E, E is an aromatic or heteroaromatic moiety, or a substituted aromatic or heteroaromatic moiety having substituents comprising from 1 to 6 non-hydrogen atoms each. In other words, E can be an aromatic moiety such as phenyl, napthyl, etc, or E can be a heteroaromatic moiety such as thienyl, pyridinyl, furyl, benzothienyl, etc. Alternatively, E can be one of these aromatic or heteroaromatic moieties, which is substituted with substituents comprising from 1 to 6 non-hydrogen atoms each. Thus, E may have one substituent, or it can have as many substituents as the ring will bear. For example, while not intending to limit the scope of the invention in any way E could be a substituted phenyl with from 1 to 5 substituents which may be the same or mixed including a monosubstituted phenyl such as methylphenyl, chlorophenyl, etc.; a disubstituted phenyl having the same substituents such as dichlorophenyl, or mixed substituents such as ethylmethylphenyl, etc.; a trisubstituted phenyl; a tetrasubstituted phenyl; or a pentasubstituted phenyl. Similarly, while not intending to be limiting, a napthyl moiety could have up to 7 substituents. Heteroaromatic moieties may also bear a number of substituents although, while not intending to be limiting, some heteroaromatic moieties may not be able to bear a substituent on the heteroatom. For example, while not intending to be limiting, a furyl moiety having an O-substituent is unlikely to be stable. Substituents have from 1 to 6 non-hydrogen atoms each, and may include, but are not limited to, hydrocarbons having up to six carbons such as methyl, ethyl, propyl isomers, butyl isomers, pentyl isomers, hexyl isomers, etc., analogous unsaturated hydrocarbons including alkenyl, alkynyl, and cyclic hydrocarbons; alkoxy having up to 5 carbon atoms; halogens, including fluoro, chloro, and bromo; hydroxyl; trifluoromethyl; CO 2 H; CN; NO 2 ; SO 3 H; etc. These substituents may be in any reasonable position on the aromatic or heteroaromatic moiety. A person of ordinary skill in the art will understand that the number of substituents will be an integer. In one embodiment E is an aromatic or heteroaromatic moiety having from 0 to 4 substituents. In another embodiment, these substituents are selected from the group consisting of methyl, methoxy, —CN, bromo, chloro, fluoro, and trifluoromethyl. For example, while not intending to be limiting, E could be unsubstituted thienyl or another heteroaromatic or aromatic ring, or E could be a substituted aromatic or heteroaromatic moiety including a monosubstituted thienyl such as methylthienyl or bromothienyl; a disubstituted thienyl moiety having identical substituents such as dimethylthienyl or dibromothienyl, or mixed substituents such as bromomethylthienyl; a trisubstituted thienyl moiety having identical or mixed substituents; a tetrasubstituted thienyl having identical or mixed substituents; a mono-, di-, tri-, or tetra-substituted phenyl; or any other aromatic or heteroaromatic moiety having up to 4 substituents. In one embodiment, all substituents comprise no more than 6 non-hydrogen atoms, i.e. there are no more than 6 non-hydrogen atoms total when all of the atoms of all of the substituents are considered. For example, for a phenyl having a trifluoromethyl and a methoxy substituent, all substituents comprise 6 non-hydrogen atoms. In another embodiment, all substituents together comprise no more than 4 non-hydrogen atoms. In another embodiment, all substituents comprise no more than 2 non-hydrogen atoms. In another embodiment, the substituent comprises 1 non-hydrogen atom. In one embodiment, the substituents are selected from the group consisting of methyl, methoxy, —CN, bromo, fluoro, and trifluoromethyl. In other embodiments E is an aromatic or heteroaromatic moiety having from 1 to 3 substituents, wherein said aromatic moiety is selected from the group consisting of phenyl, thienyl, benzothienyl, and napthyl, and said substituents are selected from the group consisting of methyl, methoxy, bromo, chloro, and fluoro. These substituents may be in any reasonable position on the aromatic or heteroaromatic moiety. A person of ordinary skill in the art will understand that the number of substituents will be an integer. In other embodiments, E is an aromatic or a heteroaromatic moiety consisting of a single aromatic ring and one or two substituents, said ring consisting of five or six atoms, and said substituents being selected from the group consisting of bromo, chloro, flouro, methyl, and methoxy. In other words, E is a single aromatic or heteroaromatic ring of five or six members (i.e. not a fused ring moiety such as naphthyl or benzothienyl) having one or two of the substituents listed. While not intending to be limiting, some possible examples such aromatic rings consisting of five or six atoms include phenyl, furyl, pyridinyl, thienyl, thiazolyl, pyrimidinyl, pyrrolyl, and imidazolyl. In other compounds, E is phenyl or thienyl having from 2 to 4 substituents, said substituents comprising no more than 3 carbon atoms each. In other words, the substituents could be methyl, ethyl, propyl, isopropyl, ester up to C3, methoxy, ethoxy, propoxy, isopropoxy, NO 2 , CF 3 , Br, Cl, F, SO 3 H or a salt, CO 2 H or a salt, NH 2 or another amine having 3 or less carbon atoms, or the like. In other embodiments, E is disubstituted thienyl. In other embodiments, E is a thienyl having one methyl and one bromo substituent. A “pharmaceutically acceptable salt” is any salt that retains the activity of the parent compound and does not impart any additional deleterious or untoward effects on the subject to which it is administered and in the context in which it is administered compared to the parent compound. A pharmaceutically acceptable salt also refers to any salt which may form in vivo as a result of administration of an acid, another salt, or a prodrug which is converted into an acid or salt. Pharmaceutically acceptable salts of acidic functional groups may be derived from organic or inorganic bases. The salt may comprise a mono or polyvalent ion. Of particular interest are the inorganic ions, lithium, sodium, potassium, calcium, and magnesium. Organic salts may be made with amines, particularly ammonium salts such as mono-, di- and trialkyl amines or ethanol amines. Salts may also be formed with caffeine, tromethamine and similar molecules. Hydrochloric acid or some other pharmaceutically acceptable acid may form a salt with a compound that includes a basic group, such as an amine or a pyridine ring. A “prodrug” is a compound which is converted to a therapeutically active compound after administration, and the term should be interpreted as broadly herein as is generally understood in the art. While not intending to limit the scope of the invention, conversion may occur by hydrolysis of an ester group or some other biologically labile group. Ester prodrugs of the compounds disclosed herein are specifically contemplated. While not intending to be limiting, an ester may be an alkyl ester, an aryl ester, or a heteroaryl ester. The term alkyl has the meaning generally understood by those skilled in the art and refers to linear, branched, or cyclic alkyl moieties. C 1-6 alkyl esters are particularly useful, where alkyl part of the ester has from 1 to 6 carbon atoms and includes, but is not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, t-butyl, pentyl isomers, hexyl isomers, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and combinations thereof having from 1-6 carbon atoms, etc. A “tetrazole” as disclosed herein is meant to be a compound wherein a carboxylic acid is substituted with a tetrazole functional group. Thus, a tetrazole of a compound of the structure would have the structure shown below. While not intending to limit the scope of the invention in any way, tetrazoles are known in the art to be interchangeable with carboxylic acids in biological systems. In other words, if a compound comprising a carboxylic acid is substituted with a tetrazole, it is expected that the compound would have similar biological activity. A pharmaceutically acceptable salt or a prodrug of a tetrazole is also considered to be a tetrazole for the purposes of this disclosure. The tetrazole group has two tautomeric forms, which can rapidly interconvert in aqueous or biological media, and are thus equivalent to one another. The tautomer of the tetrazole shown above is shown below. For the purposes disclosed herein, all tautomeric forms should be considered equivalent in every way. Compounds comprising or a pharmaceutically acceptable salt, a tetrazole, or a prodrug thereof, are specifically contemplated herein. Compounds comprising or a pharmaceutically acceptable salt, a tetrazole, or a prodrug thereof, are specifically contemplated herein. or a pharmaceutically acceptable salt, a tetrazole, or a prodrug thereof. Another embodiment comprises or a pharmaceutically acceptable salt, a tetrazole, or a prodrug thereof. In other embodiments, the compound is the acid or a pharmaceutically acceptable salt, and not a tetrazole or a prodrug. Another embodiment comprises or a pharmaceutically acceptable salt, a tetrazole, or a prodrug thereof. In other embodiments, the compound is the acid or a pharmaceutically acceptable salt, and not a tetrazole or a prodrug. One embodiment comprises derivatives of wherein said derivative has a structure as shown above except that 1 or 2 alterations are made to the α chain and/or the ω chain, wherein an alteration consists of 1) adding, removing, or substituting a non-hydrogen atom, or 2) changing the bond order of an existing covalent bond without adding or deleting said bond. The actual compounds depicted in the structure, where B has the meaning previously disclosed, are also contemplated in this embodiment. Salts, tetrazoles, and prodrugs of all of the above are also contemplated. Thus, a compound having the structure above is contemplated, as well as a pharmaceutically acceptable salt a prodrug, or a tetrazole thereof. In making reference to a derivative and alterations to the structure shown above, it should be emphasized that making alterations and forming derivatives is strictly a mental exercise used to define a set of chemical compounds, and has nothing to do with whether said alteration can actually be carried out in the laboratory, or whether a derivative can be prepared by an alteration described. However, whether the derivative can be prepared via any designated alteration or not, the differences between the derivatives and the aforementioned structure are such that a person of ordinary skill in the art could prepare the derivatives disclosed herein using routine methods known in the art without undue experimentation. The α chain is the group in the solid circle in the labeled structure above. The ω chain is the group in the dashed circle in the labeled structure above. Thus, in these embodiments said derivative may be different from the formula above at the α chain, while no alteration is made to the ω chain, as for example, in the structures shown below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. The derivatives may also be different from the formula above in the ω chain, while no alteration is made to the α chain, as shown in the examples below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. Alternatively, the derivatives may be different in both the α and ω chains, as shown in the examples below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. Changes to the structure can take several forms, if a non-hydrogen atom is added, the structure is changed by adding the atom, and any required hydrogen atoms, but leaving the remaining non-hydrogen atoms unchanged, such as in the two examples shown below, with the added atoms in bold type. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. If a non-hydrogen atom is removed, the structure is changed by removing the atom, and any required hydrogen atoms, but leaving the remaining non-hydrogen atoms unchanged, such as in the two examples shown below, with the previous location of the missing atoms indicated by arrows. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. If a non-hydrogen atom is substituted, the non-hydrogen atom is replaced by a different non-hydrogen atom, with any necessary adjustment made to the number of hydrogen atoms, such as in the two examples shown below, with the substituted atoms in bold type. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. Changing the bond order of an existing covalent bond without adding or deleting said bond refers to the changing of a single bond to a double or triple bond, changing a double bond to a single bond or a triple bond, or changing a triple bond to a double or a single bond. Adding or deleting a bond, such as occurs when an atom is added, deleted, or substituted, is not an additional alteration for the purposes disclosed herein, but the addition, deletion, or substitution of the non-hydrogen atom, and the accompanying changes in bonding are considered to be one alteration. Three examples of this type of alteration are shown below, with the top two examples showing alteration in the double bond of the α chain, and the bottom example showing alteration in the C—O single bond of the ω chain. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. If a derivative could reasonably be construed to consist of a different number of alterations, the derivative is considered to have the lowest reasonable number of alterations. For example, the compound shown below, having the modified portion of the molecule in bold, could be reasonably construed to have 1 or 2 alterations relative to the defined structure. By one line of reasoning, the first alteration would be to remove the hydroxyl group from the carboxylic acid functional group, yielding an aldehyde. The second alteration would be to change the C═O double bond to a single bond, yielding the alcohol derivative shown above. By a second line of reasoning, the derivative would be obtained by simply removing the carbonyl oxygen of the carboxylic acid to yield the alcohol. In accordance with the rule established above, the compound above is defined as having 1 alteration. Thus, an additional alteration could be made to the structure to obtain the compounds such as the examples shown below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. In one embodiment, O or S is substituted for CH 2 , as seen in several of the examples disclosed previously herein, as well as in the examples below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. Certain compounds comprise C═O, i.e. the bond order of the C—O bond is increased from a single to double bond as in the compounds shown below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. Other embodiments comprise no Br, i.e. it is removed or another atom is substituted for it, as in the examples shown below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. Other embodiments comprise no CH 3 , i.e. it is removed or another atom is substituted for it, as in the examples shown below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. In many embodiments, the compound comprises a thienyl or substituted thienyl moiety. A number of examples of these compounds are given above. However, certain embodiments may have a substituted furyl, phenyl, or other aromatic moiety, such as the examples shown below. Pharmaceutically acceptable salts, tetrazoles, and prodrugs of these compounds are also contemplated. Another embodiment comprises one the following compounds: (Z)-7-{(1R,2R)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-hydroxy-pent-1-enyl]-3-methyl-5-hydroxy-cyclopentyl}-hept-5-enoic acid acid; (Z)-7-{(1R,2R)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-hydroxy-pent-1-enyl]-3-ethyl-5-hydroxy-cyclopentyl}-hept-5-enoic acid acid; or (Z)-7-{(1R,2S)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-hydroxy-pent-1-enyl]-5-hydroxy-3-vinyl-cyclopentyl}-hept-5-enoic acid. The compounds of disclosed herein are useful for the prevention or treatment of glaucoma or ocular hypertension in mammals, or for the manufacture of a medicament for the treatment of glaucoma or ocular hypertension. Those skilled in the art will readily understand that for administration or the manufacture of medicaments the compounds disclosed herein can be admixed with pharmaceutically acceptable excipients which per se are well known in the art. Specifically, a drug to be administered systemically, it may be confected as a powder, pill, tablet or the like, or as a solution, emulsion, suspension, aerosol, syrup or elixir suitable for oral or parenteral administration or inhalation. For solid dosage forms or medicaments, non-toxic solid carriers include, but are not limited to, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, the polyalkylene glycols, talcum, cellulose, glucose, sucrose and magnesium carbonate. The solid dosage forms may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the technique described in the U.S. Pat. Nos. 4,256,108; 4,166,452; and 4,265,874 to form osmotic therapeutic tablets for control release. Liquid pharmaceutically administrable dosage forms can, for example, comprise a solution or suspension of one or more of the presently useful compounds and optional pharmaceutical adjutants in a carrier, such as for example, water, saline, aqueous dextrose, glycerol, ethanol and the like, to thereby form a solution or suspension. If desired, the pharmaceutical composition to be administered may also contain minor amounts of nontoxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like. Typical examples of such auxiliary agents are sodium acetate, sorbitan monolaurate, triethanolamine, sodium acetate, triethanolamine oleate, etc. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 16th Edition, 1980. The composition of the formulation to be administered, in any event, contains a quantity of one or more of the presently useful compounds in an amount effective to provide the desired therapeutic effect. Parenteral administration is generally characterized by injection, either subcutaneously, intramuscularly or intravenously. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol and the like. In addition, if desired, the injectable pharmaceutical compositions to be administered may also contain minor amounts of non-toxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like. The amount of the presently useful compound or compounds administered is, of course, dependent on the therapeutic effect or effects desired, on the specific mammal being treated, on the severity and nature of the mammal's condition, on the manner of administration, on the potency and pharmacodynamics of the particular compound or compounds employed, and on the judgment of the prescribing physician. The therapeutically effective dosage of the presently useful compound or compounds is preferably in the range of about 0.5 or about 1 to about 100 mg/kg/day. A liquid which is ophthalmically acceptable is formulated such that it can be administered topically to the eye. The comfort should be maximized as much as possible, although sometimes formulation considerations (e.g. drug stability) may necessitate less than optimal comfort. In the case that comfort cannot be maximized, the liquid should be formulated such that the liquid is tolerable to the patient for topical ophthalmic use. Additionally, an ophthalmically acceptable liquid should either be packaged for single use, or contain a preservative to prevent contamination over multiple uses. For ophthalmic application, solutions or medicaments are often prepared using a physiological saline solution as a major vehicle. Ophthalmic solutions should preferably be maintained at a comfortable pH with an appropriate buffer system. The formulations may also contain conventional, pharmaceutically acceptable preservatives, stabilizers and surfactants. Preservatives that may be used in the pharmaceutical compositions of the present invention include, but are not limited to, benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric, acetate and phenylmercuric nitrate. A useful surfactant is, for example, Tween 80. Likewise, various useful vehicles may be used in the ophthalmic preparations of the present invention. These vehicles include, but are not limited to, polyvinyl alcohol, povidone, hydroxypropyl methyl cellulose, poloxamers, carboxymethyl cellulose, hydroxyethyl cellulose and purified water. Tonicity adjustors may be added as needed or convenient. They include, but are not limited to, salts, particularly sodium chloride, potassium chloride, mannitol and glycerin, or any other suitable ophthalmically acceptable tonicity adjustor. Various buffers and means for adjusting pH may be used so long as the resulting preparation is ophthalmically acceptable. Accordingly, buffers include acetate buffers, citrate buffers, phosphate buffers and borate buffers. Acids or bases may be used to adjust the pH of these formulations as needed. In a similar vein, an ophthalmically acceptable antioxidant for use in the present invention includes, but is not limited to, sodium metabisulfite, sodium thiosulfate, acetylcysteine, butylated hydroxyanisole and butylated hydroxytoluene. Other excipient components which may be included in the ophthalmic preparations are chelating agents. A useful chelating agent is edetate disodium, although other chelating agents may also be used in place or in conjunction with it. The ingredients are usually used in the following amounts: Ingredient Amount (% w/v) active ingredient about 0.001-5 preservative   0-0.10 vehicle   0-40 tonicity adjuster   1-10 buffer 0.01-10 pH adjuster q.s. pH 4.5-7.5 antioxidant as needed surfactant as needed purified water as needed to make 100% For topical use, creams, ointments, gels, solutions or suspensions, etc., containing the compound disclosed herein are employed. Topical formulations may generally be comprised of a pharmaceutical carrier, cosolvent, emulsifier, penetration enhancer, preservative system, and emollient. The actual dose of the active compounds of the present invention depends on the specific compound, and on the condition to be treated; the selection of the appropriate dose is well within the knowledge of the skilled artisan. EXAMPLE 1 Compounds of Table 1 were prepared according to the following procedures. Compound 1 was prepared by methods disclosed in U.S. Pat. No. 6,124,344, incorporated by reference herein. (Z)-7-[(1R,2R,3R,5S)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tetrahydro-pyran-2-yloxy)-pent-1-enyl]-3,5-bis-(tetrahydro-pyran-2-yloxy)-cyclopentyl]-hept-5-enoic acid methyl ester (2). An acetone (24 mL) solution of acid 1 was treated with DBU (1.4 mL, 9.36 mmol) and methyl iodide (0.6 mL, 9.63 mmol). The reaction was stirred for 21 h and then 50 mL 1 M HCl was added and the mixture extracted with ethyl acetate (3×50 mL). The combined ethyl acetate solution was dried (Na 2 SO 4 ), filtered and evaporated to leave a brown oil that was used directly in the next step. (Z)-7-{(1R,2R,3R,5S)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-hydroxy-pent-1-enyl]-3,5-dihydroxy-cyclopentyl}-hept-5-enoic acid methyl ester (3). A mixture of the crude ester (2) in methanol (16 mL) was treated with pyridinium p-toluenesulfonate (2.625 g, 10.4 mmol). After 21 h, the solvent was evaporated in vacuo and the residue purified by flash chromatography on silica gel (90% ethyl acetate/hexanes→95%) to give 3 (3.453 g, 6.9 mmol, 86% for the two steps). (Z)-7-[(1R,2R,3R,5S)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-3-(tert-butyl-dimethyl-silanyloxy)-5-hydroxy-cyclopentyl]-hept-5-enoic acid methyl ester (4). A dichloromethane (14 mL) solution of 3 (3.452 g, 6.9 mmol) was treated with triethylamine (2.9 mL, 20.8 mmol), DMAP (211 mg, 1.73 mmol) and TBSCI (2.130 g, 14.1 mmol). The reaction was allowed to stir for 22 h and then was quenched by addition of 100 mL saturated NaHCO 3 solution. The mixture was extracted with CH 2 Cl 2 (3×75 mL) and the combined CH 2 Cl 2 solution was dried (Na 2 SO 4 ), filtered and evaporated. Purification by flash chromatography (10% ethyl acetate/hexane→20%) gave 4 (3.591 g, 4.9 mmol, 71%). (Z)-7-[(1R,2R,3R)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-3-(tert-butyl-dimethyl-silanyloxy)-5-oxo-cyclopentyl]-hept-5-enoic acid methyl ester (5). A mixture of alcohol 4 (3.591 g, 4.9 mmol), 4A molecular sieves (2.5 g), and NMO (867 mg, 7.4 mmol) in dichloromethane (10 mL) was treated with TPAP (117 mg, 0.33 mmol). After 1 h, the mixture was filtered through celite and the filtrate evaporated in vacuo. Purification by flash chromatography (5% ethyl acetate/hexanes→7.5%) gave 5 (2.984 g, 4.1 mmol, 84%). (Z)-7-{(1R,2S)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-hydroxy-pent-1-enyl]-5-oxo-cyclopent-3-enyl}-hept-5-enoic acid methyl ester (6). A mixture of 5 (1.486 g, 2.03 mmol), HOAc (20 mL), H 2 O (10 mL) and THF (10 mL) was stirred at 70° C. for 17 h. The reaction was then poured into 750 mL saturated NaHCO 3 solution and the resulting mixture was extracted with ethyl acetate (4×200 mL). The combined ethyl acetate solution was dried (Na 2 SO 4 ), filtered and evaporated. Flash chromatography (50% ethyl acetate/hexanes) gave 6 (497 mg, 1.03 mmol, 51%). (Z)-7-{(1R,2S)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-5-oxo-cyclopent-3-enyl}-hept-5-enoic acid methyl ester (7). A dichloromethane (6 mL) solution of 6 (497 mg, 1.03 mmol) was treated with 2,6-lutidine (143 μL, 1.22 mmol) and TBSOTf (0.26 mL, 1.13 mmol). After 1.5 h, 50 mL saturated NaHCO 3 was added and the resulting mixture was extracted with 25 mL CH 2 Cl 2 . The CH 2 Cl 2 layer was washed with 50 mL 1 M HCl and 50 mL brine. The CH 2 Cl 2 solution was then dried (Na 2 SO 4 ), filtered and evaporated. Purification by flash chromatography (8% ethyl acetate/hexanes→10%) gave 7 (553 mg, 0.93 mmol, 90%). (Z)-7-{(1R,2S)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-5-oxo-3-vinyl-cyclopentyl}-hept-5-enoic acid methyl ester (8, B is ═CH 2 ). Vinylmagnesium bromide (1.25 mL, 1.25 mmol, 1 M/THF) was added to a 0° C. mixture of CuI (158 mg, 0.83 mmol) in 2 mL THF. The dark mixture was stirred for 5 min. and then was cooled to −78° C. A solution of Enone 7 (169 mg, 0.28 mmol) in 1 mL THF was added by cannula, rinsing with 0.25 mL THF. The mixture was stirred for 1.5 h and then 20 mL saturated NH 4 Cl was added. The resulting mixture was stirred for 20 min. and then was extracted with ethyl acetate (3×20 mL). The combined ethyl acetate solution was dried (Na 2 SO 4 ), filtered and evaporated. Purification by flash chromatography on silica gel (7.5% ethyl acetate/hexanes) gave the title ketone (138 mg, 0.22 mmol, 79%). (Z)-7-{(1R,2R)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-3-methyl-5-oxo-cyclopentyl}-hept-5-enoic acid methyl ester (8, B is hydrogen). A −78° C. mixture of CuCN (121 mg, 1.35 mmol) in THF (1 mL) was treated with MeLi (1.4 mL, 1.96 mmol, 1.4 M/ether). The mixture was stirred for 5 min. at −78° C. and for 10 min. at room temperature. The resulting solution was recooled to −78° C. and a solution of enone 7 (211 mg, 0.35 mmol) in THF (1 mL) was added by cannula, rinsing with 0.5 mL THF. After 45 min., 25 mL saturated NH 4 Cl solution was added and the mixture stirred for 15 min. at room temperature. The mixture was extracted with dichloromethane (3×20 mL) and the combined dichloromethane solution was dried (Na 2 SO 4 ), filtered and evaporated to give 175 mg (0.29 mmol, 81%) of 8. (Z)-7-{(1R,2R)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-5-hydroxy-3-methyl-cyclopentyl}-hept-5-enoic acid methyl ester (9, B is hydrogen). A methanol (0.8 mL) solution of ketone 8 (B is hydrogen, 102 mg, 0.17 mmol) was treated with NaBH 4 (11 mg, 0.29 mmol). After 1.5 h, the reaction was quenched with 15 mL 1 M HCl and the resulting mixture extracted with dichloromethane (3×15 mL). The combined dichloromethane solution was washed with brine (25 mL) and then was dried (Na 2 SO 4 ), filtered and evaporated to give 98 mg of the alcohols 9. (Z)-7-{(1R,2R)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-hydroxy-pent-1-enyl]-5-hydroxy-3-methyl-cyclopentyl}-hept-5-enoic acid methyl ester (10, B is hydrogen). A solution of alcohols 9 (B is hydrogen, 117 mg, 0.19 mmol) in HOAc (1.6 mL)/H 2 O (0.8 mL)/THF (0.8 mL) was heated at 70° C. for 2 h and then stored in the freezer overnight. The reaction was incomplete and so was heated at 70° C. for a further 2 h. The reaction was quenched by addition of 100 mL saturated NaHCO 3 solution and the resulting mixture was extracted with ethyl acetate (4×100 mL). The combined ethyl acetate solution was dried (Na 2 SO 4 ), filtered and evaporated. Flash chromatography (30% ethyl acetate/hexanes→35%→40%→50%) gave two C9 diastereomers: high R f 35 mg (0.07 mmol, 32%) and low R f 46 mg (0.092 mmol, 42%). (Z)-7-{(1R,2R)-2-[(E)-(S)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-hydroxy-pent-1-enyl]-5-hydroxy-3-methyl-cyclopentyl}-hept-5-enoic acid (11, high R f diastereomer). A THF (1.6 mL) solution of 10 (B is hydrogen, 35 mg, 0.07 mmol) was treated with 0.5 M LiOH (0.42 mL, 0.21 mmol). The reaction was allowed to stir for 24 h and then 10 mL 1 M HCl was added. The resulting mixture was extracted with dichloromethane (3×15 mL) and the combined dichloromethane solution was dried (Na 2 SO 4 ), filtered and evaporated. Purification by flash chromatography (5% methanol/dichloromethane→7%) gave the title acid (30 mg, 0.06 mmol, 88%). 300 MHz NMR (CDCl 3 , ppm) δ 6.58 (s, 1 H), 5.6-5.3 (m, 4 H), 4.3-4.1 (m, 2 H), 2.9-2.7 (m, 2 H), 2.32 (s, 3 H), 2.4-1.2 (overlapping m, 15 H), 0.99 (d, J=6.6 Hz, 3 H). TABLE 1 FUNCTIONAL DATA EC5O (nm) Rf STRUCTURE HFP HEP1 HEP2 HEP3A HEP4 HTP HIP HDP Low >10 5 NA NA >10 5 NA NA NA High 43 >10 5 >10 5 >10 5 NA NA Low >10 5 NA NA NA NA NA NA NA High 61 >10 5 >10 5 304 >10 5  243 NA NA Low 1534 NA NA 554 >10 5 NA NA NA High 742 NA NA 6010 >10 5 1807 NA NA Low >10 5 NA NA NA >10 5 NA NA NA High >10K NA NA NA NA >10K NA NA EXAMPLE 2 The biological activity of the compounds of Table 1 was tested using the following procedures. Methods for FLIPR™ Studies (a) Cell Culture HEK-293(EBNA) cells, stably expressing one type or subtype of recombinant human prostaglandin receptors (prostaglandin receptors expressed: hDP/Gqs5; hEP 1 ; hEP 2 /Gqs5; hEP 3A /Gqi5; hEP 4 /Gqs5; hFP; hIP; hTP), were cultured in 100 mm culture dishes in high-glucose DMEM medium containing 10% fetal bovine serum, 2 mM 1-glutamine, 250 μg/ml geneticin (G418) and 200 μg/ml hygromycin B as selection markers, and 100 units/ml penicillin G, 100 μg/ml streptomycin and 0.25 μg/ml amphotericin B. (b) Calcium Signal Studies on the FLIPR™ Cells were seeded at a density of 5×10 4 cells per well in Biocoat® Poly-D-lysine-coated black-wall, clear-bottom 96-well plates (Becton-Dickinson) and allowed to attach overnight in an incubator at 37° C. Cells were then washed two times with HBSS-HEPES buffer (Hanks Balanced Salt Solution without bicarbonate and phenol red, 20 mM HEPES, pH 7.4) using a Denley Cellwash plate washer (Labsystems). After 45 minutes of dye-loading in the dark, using the calcium-sensitive dye Fluo-4 AM at a final concentration of 2 μM, plates were washed four times with HBSS-HEPES buffer to remove excess dye leaving 100 μl in each well. Plates were re-equilibrated to 37° C. for a few minutes. Cells were excited with an Argon laser at 488 nm, and emission was measured through a 510-570 nm bandwidth emission filter (FLIPR™, Molecular Devices, Sunnyvale, Calif.). Drug solution was added in a 50 μl volume to each well to give the desired final concentration. The peak increase in fluorescence intensity was recorded for each well. On each plate, four wells each served as negative (HBSS-HEPES buffer) and positive controls (standard agonists: BW245C (hDP); PGE 2 (hEP 1 ; hEP 2 /Gqs5; hEP 3A /Gqi5; hEP 4 /Gqs5); PGF 2α (hFP); carbacyclin (hIP); U-46619 (hTP), depending on receptor). The peak fluorescence change in each drug-containing well was then expressed relative to the controls. Compounds were tested in a high-throughput (HTS) or concentration-response (CoRe) format. In the HTS format, forty-four compounds per plate were examined in duplicates at a concentration of 10 −5 M. To generate concentration-response curves, four compounds per plate were tested in duplicates in a concentration range between 10 −5 and 10 −11 M. The duplicate values were averaged. In either, HTS or CoRe format each compound was tested on at least 3 separate plates using cells from different passages to give an n≧3. The results of the activity studies presented in the table demonstrate that the compounds disclosed herein are selective prostaglandin FP agonists, and are thus useful for the treatment of glaucoma, ocular hypertension, the other diseases or conditions related to the activity of the FP receptor. The foregoing description details specific methods and compositions that can be employed to practice the present invention, and represents the best mode contemplated. However, it is apparent for one of ordinary skill in the art that further compounds with the desired pharmacological properties can be prepared in an analogous manner, and that the disclosed compounds can also be obtained from different starting compounds via different chemical reactions. Similarly, different pharmaceutical compositions may be prepared and used with substantially the same result. Thus, however detailed the foregoing may appear in text, it should not be construed as limiting the overall scope hereof; rather, the ambit of the present invention is to be governed only by the lawful construction of the appended claims.

A compound comprising or a pharmaceutically acceptable salt or a prodrug thereof, having the groups described in detail herein is disclosed. Also disclosed herein are compounds comprising or derivatives thereof, or pharmaceutically acceptable salts, tetrazoles, or prodrugs of compounds of the structure or derivatives thereof, said derivatives being described in detail herein. Also disclosed herein are methods of treating diseases or conditions, including glaucoma and elevated intraocular pressure. Compositions and methods of manufacturing medicaments related thereto are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority under 35 U.S.C. §119(e) on U.S. Provisional Application No. 60/079,485 entitled “SYSTEM AND METHOD FOR INTELLIGENT DATA INPUT FROM A MACHINE READABLE MEDIUM,” filed on Mar. 26, 1998, by John T. Piatek, the entire disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION The present invention generally relates to a data input method which allows for two-dimensional bar codes, RFID tags and chips, and other high-capacity machine-readable media to populate any database and/or software “screens,” even though these databases and screens have dissimilar data field formats (dissimilar in both the type and order of information required). More particularly, the present invention relates to a method of intelligent data input using an interactive process between machine-readable media and translation software. Databases and/or computer screens are generally populated by manual keyboard entry whereby a data entry operator manually enters data into the appropriate data field of the database or screen by key strokes on a computer keyboard. Because such manual data entry is a very labor-intensive task, alternative methods for data entry have been developed in which the data is input from bar codes and/or other machine-readable media. The current state-of-the-art for data input from bar codes and other machine-readable media to databases/screens includes three methods: (1) keyboard wedge placement and input, (2) serial transmission, and (3) data identification. The first method uses what is known as keyboard wedge placement and input whereby the operator manually places the computer's cursor in the data field to be populated and then scans a bar code that fills in this field so as to emulate keystrokes. While this method eliminates the need for an operator to manually enter the data into selected data fields, it still requires the operator to manually select each data field and to populate each data field one at a time. The second method utilizes serial transmission to automatically populate multiple data fields without requiring human intervention or selection of the data fields once the serial transmission is initiated. This method, however, requires that the host software (i.e., the database program) be specially modified or programmed so that when it sees data coming in from a specific communication port (i.e., where a scanner is connected), the host software directs that information to the appropriate data field. The third method utilizes data identifiers. Using this method, the data, typically sent via file transfer, has special data identifiers (e.g., ASCII characters) that the host software recognizes and performs translation functions to reformat this data and/or to direct this data to the appropriate data field. However, like the second method, the host software must be specially constructed or modified to recognize data identifiers and perform the translation and/or placement functions. Such special modifications to the host software may render it unusable for maintaining other databases. SUMMARY OF THE INVENTION Accordingly, it is an aspect of the present invention to provide a method for populating a database or screen that overcomes the above problems by automating the “placement” and “translation” functions without requiring any modification to the host software (database or screen). Another aspect of the present invention is to provide a method whereby any existing or off-the-shelf database software can be “front-ended” with portable high-capacity machine-readable media, such as two-dimensional bar codes, without requiring custom modification of the database software. An additional aspect of the invention is to provide a method and system for populating a database and/or software screen in a computer, where the data read from a portable high-capacity machine-readable medium may be reformatted in one or more different ways in accordance with characters contained within the machine-readable medium. To achieve these and other aspects and advantages, a method (or system) of the present invention populates a database and/or software screen in a computer with data read from portable high-capacity machine-readable media by performing the steps of: loading and executing an interpretive software program in the computer, reading a portable high-capacity machine-readable medium with a reading device coupled to the computer, and using the interpretive software program to identify any instructor characters that are present in the data read from the machine-readable medium, and reformat the data in the machine-readable medium that follows the corresponding instructor character in a manner associated with the instructor character. An additional aspect of the present invention is to provide a method for populating a database and/or software screen in a computer with data read from a portable high-capacity machine-readable medium, such that the data may populate data fields within the database that are specified in characters contained in the machine-readable medium. To achieve this and other aspects and advantages, the method of the present invention comprises the steps of: loading and executing an interpretive software program in the computer; reading a portable high-capacity machine-readable medium with a reading device coupled to the computer; and using the interpretive software program to identify any instructor characters that are present in the data read from the machine-readable medium, identify a data field within the database and/or software screen that corresponds to each identified instructor character, and populate the identified data field with data in the machine-readable medium that follows the corresponding instructor character. Still another aspect of the present invention is to provide a method for populating a database and/or software screen in a computer with data read from a portable high-capacity machine-readable medium, where the data may be accepted or rejected based upon the presence of a special character contained in the machine-readable medium. To achieve this and other aspects and advantages, the method of the present invention comprises the steps of: loading and executing an interpretive software program in the computer; reading a portable high-capacity machine-readable medium with a reading device coupled to the computer; and using the interpretive software program to identify any qualifier character that is present in the data read from the machine-readable medium, ignore the data if no qualifier character is identified, and populate the database and/or software screen with the data read from the machine-readable medium if a qualifier character is identified. These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a system diagram in block form of a system constructed in accordance with the present invention; FIG. 2 is a flow chart illustrating the operations performed by the interpretive software program of the present invention; and FIGS. 3A through 3C are block diagrams illustrating examples of the operation of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention utilizes intelligence embedded in a portable high-capacity machine-readable medium and an intermediary software program called an INTERPRETIVE SOFTWARE PROGRAM (ISP). The ISP is loaded into the host system prior to any scanning function. The intelligence embedded in the bar code is the form of special ASCII characters called a QUALIFIER or an INSTRUCTOR CHARACTER as described further below. The machine-readable medium is preferably provided in the form of a two-dimensional symbology, particularly a PDF417 two-dimensional bar code. PDF417 bar codes are preferred due to the large amount of data that may be stored in a relatively small area, as well as the ability to build redundancy and error checking into the symbology and thereby provide consistent and accurate results. FIG. 1 shows an example of one computer hardware system 20 that may be used, in whole or in part, to implement various features of the method of the present invention. As shown in FIG. 1, computer hardware system 20 includes a central processing unit (CPU) 30 ; a random access memory (RAM) 31 ; a read only memory (ROM) 32 ; a display monitor 33 ; a display interface 34 connected to display monitor 33 ; a data storage device 35 ; a first input/output (I/O) interface 36 connected to data storage device 35 ; a keyboard 37 ; a second I/O interface 38 connected to keyboard 37 ; an information receiving device 39 connected to a third I/O interface 43 ; a printer 40 ; a printer interface 41 connected to printer 40 ; and a system bus 42 for interconnecting CPU 30 , RAM 31 , ROM 32 , display interface 34 , first I/O interface 36 , second I/O interface 38 , and printer interface 41 . As described below, information receiver 39 may take any appropriate form for receiving data from the particular form of machine-readable data used for the particular embodiment or for receiving machine-recognizable information that may be processed by a computer. Preferably, data storage device 35 is a computer hard disk drive. As will be apparent to those of ordinary skill in the art, the components of computer hardware system 20 may be incorporated into a personal computer or a portable laptop computer, with the possible exception of information receiver 39 and printer 40 . However, as will become apparent from the following description of the present invention, certain components of computer hardware system 20 may be eliminated depending upon the manner in which it is used within the confines of the present invention. For example, if computer hardware system 20 were used solely for receiving data and displaying the received data, keyboard 37 may be eliminated and printer 40 would become optional, unless one wished to print out information displayed on display monitor 33 . By eliminating keyboard 37 and/or printer 40 , computer hardware system 20 may be implemented in a very portable, small integral device. Clearly, the particular form taken by computer hardware system 20 will depend upon the manner and environment in which the system is used. Further, computer system 20 may also be configured with a cellular telephone/modem, a global positioning system (GPS), digital camera, facsimile machine, image scanner, DVD drive, CD-ROM drive, fax/modem, or other device commonly used in or with a computer system. In accordance with the present invention, the ISP component of the present invention is loaded into the host computer system. As described below, the loaded ISP has a defined file configuration. Subsequently, the application software to be populated is loaded into the subject host system. The application software may be any commercially-available application software of the type that is to be populated with data. Such application programs generally include database software (e.g., Microsoft Access® and FoxPro®, Borland Paradox®, etc.) or display screen configuration software. Once both the ISP and the application program are loaded and running, the host system is prepared to accept bar code scans. To illustrate the manner by which the inventive method operates, reference is made to the flow chart shown in FIG. 2, which shows the steps that the ISP is programmed to perform. As shown, the ISP first looks for data received from a communication port of the computer system that is connected to a data reading device, such as a the two-dimensional bar code scanner (step 102 ). When data is detected, the ISP determines that a bar code or the like has been scanned. When a bar code is scanned, the ISP will search the received data for a QUALIFIER character (e.g., “*”) (step 104 ). If a QUALIFIER character is present, the ISP approves that data as acceptable to the database to be populated. If it is not present, this data will be ignored and the program returns to step 102 where it looks for data from the bar code scanner. For “approved” data, the ISP next searches for and reads INSTRUCTOR CHARACTERs in the received data (step 106 ). Depending on the instructions resident in the ISP, the ISP will act on these INSTRUCTOR CHARACTERs to either reformat and/or translate data (e.g., the instructions for a “%” character might be that %=“name” and therefore “name” will flow into the database or screen) or place data in a particular field of the database or screen (e.g., the instruction for “˜” might be that ˜=“go home to top of screen” and “$” might be that $=“go down one line”) (step 108 ). Thus, as described above, a two-dimensional bar code (or other media), working in conjunction with the ISP will: (1) accept or refuse data; (2) translate or reformat data; and (3) place data in the appropriate data field. This is all accomplished without modifying the host system database or screens. The method of the present invention provides the user considerable flexibility. For instance, as described further below, the same bar code can be interpreted by two different ISPs to populate two dissimilar databases or screens. In addition, two dissimilar bar codes (but containing the appropriate QUALIFIER and INSTRUCTOR CHARACTERs) can be interpreted by the same ISP to populate the same database or screen. Once again, this is accomplished without modifying the existing database or screen in any manner whatsoever. As an example, consider a two-dimensional bar code that contains data on a person's name and address. For a first particular database to be populated, the “name” must populate a data field on the first line of the screen while the “address” populates the second line of the screen. As illustrated in block 200 of FIG. 3A, the data, which is encoded in a two-dimensional bar code or the like, may include a string of AS QUALIFIER CHARACTER (“*”) followed by one or more first INSTRUCTOR CHARACTERs (“˜”, “$”, and “%”), an associated first data string for a first data field identified by one of the first INSTRUCTOR CHARACTERs (“%”), one or more second INSTRUCTOR CHARACTERs, a second data string for a second data field identified by one of the second INSTRUCTOR CHARACTERs (“#”). Although not illustrated, the encoded data may include additional INSTRUCTOR CHARACTERs and associated data strings. As illustrated in block 202 , the ISP may be programmed to recognize the QUALIFIER CHARACTER (“*”) so as to accept or reject the data that follows, as well as the INSTRUCTOR CHARACTERs (“˜”, “$”, “%”, and “#”). As specifically shown in this example, ISP interprets the “˜” character as a command to move the computer's cursor to the “home” location (i.e., the top left corner of the display screen) and interprets the “$” character as a command to move the cursor down one line on the screen. The ISP further recognizes the “% ” character and uses a predefined association therein to determine that the data string following the “% ” character is a “name,” as identified in the application database program for a specific data field. Similarly, the ISP can be programmed to determine that the data string following the “#” character is an “address,” as identified in the database program for another specific data field. Block 204 of FIG. 3A illustrates how the display screen may be populated using the ISP of block 202 and the data of block 200 . Thus, instead of having to move a cursor or program the host software to recognize data identifiers and perform translation and placement functions, the ISP contains instructions to place this data in the appropriate data field. FIG. 3B shows a second example where the same data in the same bar code (block 210 ) may be used to populate a database that is different from that described above in the first example. For the second database to be populated, one might want to change “name” to mean “applicant” and change “address” to mean “location” and fill different data fields (e.g., second line for applicant and fourth line for location). An ISP (block 212 ) can be created to perform these functions without having to change the raw data in the bar code (block 210 ) or modify the receiving database software or screen. Thus, in the second example, the data of bar code 210 may be translated using the ISP parameters shown in block 212 to place the data in the appropriate data fields and locations as shown in block 214 . FIG. 3C shows a third example in which data in a different bar code (block 220 ) is interpreted using the same ISP (block 222 ) as in the second example to obtain the same results (block 224 ). As illustrated, the data in the different bar code has the “location” and “applicant” data presented in a reverse order, but the same ISP interprets the data and populates the screen and database in the same manner as in the second example. Although the present invention has been described as using two-dimensional bar codes, it will be appreciated by those skilled in the art that the inventive methods may be carried out using any other portable high-capacity machine-readable medium. Further, the present invention has been described as using ISPs that recognize specific characters and perform specific functions in response to those characters. However, the present invention may be practiced with the ISP(s) programmed to recognize any character and to perform the above-mentioned functions in response to such characters. The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents.

A system and method are provided for populating a database and/or software screen in a computer with data read from portable high-capacity machine-readable media. The method of the present invention includes the steps of: loading and executing an interpretive software program in the computer; reading a portable high-capacity machine-readable medium with a reading device coupled to the computer; and using the interpretive software program to identify any qualifier character that is present in the data read from the machine-readable medium, ignore the data if no qualifier character is identified, and populate the database and/or software screen with the data read from the machine-readable medium if a qualifier character is identified. The method may additionally, or alternatively, include the step of using the interpretive software program to identify any instructor characters that are present in the data read from the machine-readable medium, identify a data field within the database and/or software screen that corresponds to each identified instructor character, and populate the identified data field with data in the machine-readable medium that follows the corresponding instructor character.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a fan frame body structure, and more particularly to a series fan frame body structure made of different materials. The vibration frequencies of the fan frames of the series fan are different from each other so that the co-vibration of the fan is reduced to lower the noise. 2. Description of the Related Art The materials of the existent fan frames can be generally classified into two types, that is, metal frame body made by means of casting and plastic frame body made by means of injection molding. The cast metal frame body such as aluminum-made frame body has a higher price due to higher material cost. The plastic frame body made by means of injection molding, such as PBT, PA66 and PPE frame body has a much cheaper price than the metal frame body due to lower material cost so that the plastic frame body is popularly used in this field. The forms of the current fans include one-fan form and series fan form. The fan in the one-fan form has a frame body simply made of plastic material such as PBT, PA66 or PPE. The series fan has two frame bodies serially connected with each other. The frame bodies are made of the same material of the same composition. For example, both frame bodies are made of PBT, PA66 or PPE. No matter which form the fan has, the material and composition of the frame bodies are the same. Therefore, in the case that in operation of the fan, the excited frequency of the fan is close to the natural frequency of the fan frame, the fan will severely co-vibrate to make noise. This will ill affect the components of the fan to deteriorate the reading efficiency of hard disc of the system. Moreover, the lifetime of the system and the fan will be shortened. It is therefore tried by the applicant to provide a series fan frame body structure made of different materials to solve the problem of co-vibration of the fan. SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a series fan frame body structure made of different materials. Due to the different materials, the vibration frequencies of the fan frames of the series fan are different from each other so that the co-vibration of the fan is reduced to lower the noise. To achieve the above and other objects, the series fan frame body structure made of different materials of the present invention includes: a first fan including a first fan frame made of a first kind of plastic material; and a second fan including a second fan frame made of a second kind of plastic material. The second fan frame made of the second kind of plastic material is serially connected with the first fan frame made of the first kind of plastic material. The first kind of plastic material is different from the second kind of plastic material in composition. The first kind of plastic material is one of PBT, PA66, PPE, PA, PC, ABS and PPS, while the second kind of plastic material is another of PBT, PA66, PPE, PA, PC, ABS and PPS. The first fan frame vibrates at a first vibration frequency, while the second fan frame vibrates at a second vibration frequency. The first vibration frequency is different from the second vibration frequency. In the above series fan frame body structure, the first fan frame has a first opening and a second opening. The first and second openings are respectively formed on two opposite sides of the first fan frame. A first flow passage communicates the first opening and the second opening with each other. A first base seat is positioned in the first flow passage. A first fan impeller is disposed on the first base seat. In the above series fan frame body structure, the second fan frame has a third opening and a fourth opening. The third and fourth openings are respectively formed on two opposite sides of the second fan frame. A second flow passage communicates the third opening and the fourth opening with each other. A second base seat is positioned in the second flow passage. A second fan impeller is disposed on the second base seat. According to the above arrangement, the co-vibration of the series fan can be effectively reduced to remove the vibration frequency. BRIEF DESCRIPTION OF THE DRAWINGS The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein: FIG. 1A is a perspective exploded view of the series fan structure of the present invention; FIG. 1B is a perspective assembled view of the series fan structure of the present invention; FIG. 1C is a top view of the series fan structure of the present invention; FIG. 2 is a sectional view taken along line X-X of FIG. 1C ; FIG. 3 is a sectional view taken along line Y-Y of FIG. 1C ; FIG. 4A is a diagram showing the comparison between the operational vibration of the fan frame of the series fan of the present invention and the fan frame of the conventional fan; and FIG. 4B is an enlarged diagram of a range of FIG. 4A . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described hereinafter with reference to the drawings, wherein the same components are denoted with the same reference numerals. Please refer to FIGS. 1A, 1B, 1C, 2 and 3 . FIG. 1A is a perspective exploded view of the series fan structure of the present invention. FIG. 1B is a perspective assembled view of the series fan structure of the present invention. FIG. 1C is a top view of the series fan structure of the present invention. FIG. 2 is a sectional view taken along line X-X of FIG. 1C . FIG. 3 is a sectional view taken along line Y-Y of FIG. 1C . As shown in FIGS. 1A to 1C, 2 and 3 , the series fan frame body structure made of different materials of the present invention includes a first fan 10 and a second fan 20 , which are serially connected with each other. The first fan 10 includes a first fan frame 11 made of a first kind of plastic material. A first opening 12 and a second opening 13 are respectively formed on two opposite sides of the first fan frame 11 . A first flow passage 16 communicates the first opening 12 and the second opening 13 with each other. A first base seat 15 is positioned in the first flow passage 16 in adjacency to the second opening 13 . Multiple radial support ribs are disposed on an outer circumference of the first base seat 15 to connect with an inner wall of the first fan frame 11 . A first fan impeller 14 is rotatably disposed on the first base seat 15 . The second fan 20 includes a second fan frame 21 made of a second kind of plastic material. A third opening 22 and a fourth opening 23 are respectively formed on two opposite sides of the second fan frame 21 . A second flow passage 26 communicates the third opening 22 and the fourth opening 23 with each other. A second base seat 25 is positioned in the second flow passage 26 in adjacency to the third opening 22 . Multiple radial support ribs are disposed on an outer circumference of the second base seat 25 to connect with an inner wall of the second fan frame 21 . A second fan impeller 24 is rotatably disposed on the second base seat 25 . The second opening 13 of the first fan 10 is correspondingly adjacent to the third opening 22 of the second fan 20 . The first flow passage 16 communicates with the second flow passage 26 . When the first and second fan impellers 14 , 24 rotate, the fluid flows through the first, second, third and fourth openings 12 , 13 , 22 , 23 . The first and second fans 10 , 20 can be serially connected by any conventional measure. For example, the opposite sides of the first and second fans 10 , 20 can be provided with mating members. Alternatively, the four corners of the two fans 10 , 20 can be formed with perforations and four securing members can be correspondingly passed through the perforations to lock the two fans with each other. Still alternatively, the two fans can be connected with each other by means of adhesion. It should be noted that the first plastic material and the second plastic material are different from each other in composition. The first plastic material is one of PBT (Polybutylene Terephthalate), PA66 (Polyamide 66 Resin), PPE, PA, PC, ABS and PPS. The second plastic material is another of PBT, PA66, PPE, PA, PC, ABS and PPS. In order to specifically distinguish the different materials from each other, the different materials are shown by different sectional lines in the drawings. As shown in the drawings, the first fan frame is made of PA66, while the second fan frame is made of PBT in adaptation to the first fan frame. In another embodiment, the first fan frame is made of PBT, while the second fan frame is made of PA66 in adaptation to the first fan frame. The plastic material of the first fan frame 11 is different from the plastic material of the second fan frame 21 in composition. Therefore, when the first and second fan impellers 14 , 24 operate, the first fan frame 14 vibrates at a first vibration frequency, while the second fan frame 24 vibrates at a second vibration frequency. The first vibration frequency is different from the second vibration frequency. Moreover, the first and second base seats 15 , 25 not only serve to support the first and second fan impellers 14 , 24 , but also serve to dissipate the heat. Accordingly, the first base seat 15 can be made of the same plastic material as the first plastic material of the first fan frame 11 or made of a metal material such as aluminum or copper. Similarly, the second base seat 25 can be made of the same plastic material as the second plastic material of the second fan frame 21 or made of a metal material such as aluminum or copper. Please now refer to FIGS. 4A and 4B . FIG. 4A is a diagram showing the comparison between the operational vibration of the fan frame of the series fan of the present invention and the fan frame of the conventional fan. FIG. 4B is an enlarged diagram of a range of FIG. 4A . In the diagrams, the curve F 1 indicates the fan frame of the conventional series fan is made of single material of PBT. The curve F 2 indicates the fan frame of the conventional series fan is made of single material of PA66. The curve F 3 indicates the first fan frame 11 of the first fan 10 of the present invention is made of PA66, while the second fan frame 21 of the second fan 20 is made of PBT. The curve F 4 indicates the first fan frame 11 of the first fan 10 of the present invention is made of PBT, while the second fan frame 21 of the second fan 20 is made of PA66. In FIG. 4A , the horizontal data mean the frequency up to 5000 Hz, while the vertical data mean the vibration g value. FIG. 4B is an enlarged diagram of a range of FIG. 4A from 0 to 1600 Hz. It can be seen from FIGS. 4A and 4B that as a whole, the vibration g value presentation of curve F 3 of the present invention versus the respective frequencies is lower than the curves F 1 and F 2 of the conventional fans. However, as shown by the curve F 4 , it is also possible that the vibration of the conventional fan is not greatly improved as expected. In conclusion, the first and second fan frames of the series fan of the present invention are made of different materials. The different materials have different vibration frequencies so that the co-vibration is reduced to remove the vibration frequency. The present invention has been described with the above embodiments thereof and it is understood that many changes and modifications in the above embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.

A series fan frame body structure made of different materials includes at least two fans, which are serially connected with each other. The fan frames of the two fans are made of different plastic materials. Accordingly, the excited frequency of the fan is prevented from being close to the natural frequency of the fan frames. Therefore, the vibration frequencies of the fan frames are different from each other so that the co-vibration is reduced to lower the noise. By means of the series fan frame body structure made of different materials, the problem of vibration of the fan is effectively improved.

BACKGROUND [0001] 1. Technical Field [0002] The disclosed and claimed concept relates generally to handheld electronic devices and, more particularly, to a method of reflecting on another device a change to a browser cache on a handheld electronic device. [0003] 2. Description of the Related Art [0004] Numerous types of handheld electronic devices are known. Examples of handheld electronic devices include, for instance, personal data assistants (PDAs), handheld computers, two-way pagers, cellular telephones, and the like. Many handheld electronic devices also feature a wireless communication capability, although many such handheld electronic devices are stand-alone devices that are functional without communication with other devices. [0005] Some handheld electronic devices that are sold with certain software resident thereon and are configured to allow additional software developed by third parties to be installed and executed on the electronic handheld device. In order to facilitate the use of such third-party software, the manufacturer of the device may sell the device with original software that is sufficiently versatile to enable cooperation between the original software and third-party software. Such third-party software may be provided on the device when originally provided to a consumer, or may be added after purchase. While such handheld electronic devices and software have been generally effective for their intended purposes, such handheld electronic devices have not been without limitation. [0006] For instance, the original software provided by a manufacturer may be configured to be so versatile as to be somewhat burdensome to use. For example, the original software may provide a routine such as an Application Programming Interface (API) that third-party software can employ to receive notifications in response to certain events on the handheld electronic device. Due to the intended versatility of the original software, the original software may provide many more notifications than are needed or are usable by the third-party software. The processing of so many unnecessary notifications undesirably adds processing overhead and consumes both processing and power resources. Moreover, despite their versatility, such APIs may still provide fewer than all of the functions that might be desirable for use with certain third-party software. For instance, the API may provide certain notifications, but such notifications may provide less than all of the data that would be desirable for proper operation of the third-party software. BRIEF DESCRIPTION OF THE DRAWINGS [0007] A further understanding of the disclosed and claimed concept can be obtained from the following Description when read in conjunction with the accompanying drawings in which: [0008] FIG. 1 is a schematic depiction of an improved handheld electronic device in accordance with the disclosed and claimed concept in communication with a network; [0009] FIG. 2 is a schematic depiction of a portion of a memory on the handheld electronic device of FIG. 1 ; [0010] FIG. 3 is an exemplary flowchart of at least a portion of an improved method that can be performed on the improved handheld electronic device of FIG. 1 ; and [0011] FIG. 4 is an exemplary flowchart of at least a portion of another method that can be performed on the improved handheld electronic device of FIG. 1 . [0012] Similar numerals refer to similar parts throughout the specification. DESCRIPTION [0013] An improved handheld electronic device 4 is depicted schematically in FIG. 1 as being in communication with a network 8 . The exemplary network 8 enables communication between it and the handheld electronic device 4 via an antenna 10 that is connected through the network 8 with a server 12 . The exemplary network 8 communicates wirelessly with the handheld electronic device 4 , although it is understood that the network 8 could have a wired connection with the handheld electronic device 4 without departing from the present concept. [0014] The exemplary handheld electronic device 4 comprises an input apparatus 16 , a processor apparatus 20 , and an output apparatus 24 . The processor apparatus 20 is configured to process input received from the input apparatus 16 and to provide output to the output apparatus 24 . [0015] The processor apparatus 20 comprises a processor and a memory 28 . While not expressly depicted herein, it is understood that the processor could be any of a wide variety of processors, such as a microprocessor (NP) that is responsive to input from the input apparatus 16 , that provides output to the output apparatus 24 , and that interfaces with the memory 28 . [0016] The memory 28 is depicted schematically in FIG. 2 . The memory 28 can be any of a variety of types of internal and/or external storage media such as, without limitation, RAM, ROM, EPROM(s), EEPROM(s); and the like that provide a storage register for data such as in the fashion of an internal storage area of a computer, and can be volatile memory or nonvolatile memory. The memory 28 additionally includes a number of routines stored therein that are executable on the processor, as will be set forth below in greater detail. As employed herein the expression “a number of” and variations thereof shall refer broadly to any nonzero quantity, including a quantity of one. The routines can be in any of a variety of forms such as, without limitation, software, firmware, and the like. [0017] The memory 28 comprises a browser cache 32 having a number of files 36 stored therein within a directory structure. Each file 36 in the browser cache 32 has a file name 40 and has stored therein, for example, an object 44 , a location from where the object 44 was obtained, such as a Uniform Resource Locator (URL) 48 , and an expiry date 52 for the object 44 . Additional relevant information may be stored in each file without departing from the present concept. [0018] The memory 28 additionally has stored therein an operating system 56 , an API 60 , and a browser routine 64 , among other routines as mentioned above. As is understood in the relevant art, the browser routine 64 is operable to obtain and process various items such as HyperText Markup Language (HTML) documents. A given HTML document may comprise, for example, text, and may additionally comprise descriptions of locations where additional objects may be obtained and which are to be inserted into the text. Exemplary objects that are insertable into text would include images, executable code such as JavaScript, and other objects. If an HTML document that is being processed by the browser routine 64 comprises one or more locations, the objects stored at such locations must be obtained in one fashion or another for inclusion in the output that results from the such processing of the HTML document. The locations may, for example, be URLs on a network such as the Internet. [0019] In order to reduce communication bandwidth, such as a bandwidth of the wireless communication enabled between the handheld electronic device 4 and the network 8 , certain of the needed objects may be stored, i.e., saved, in the browser cache 32 as objects 44 stored within the files 36 . For example, if an HTML document being processed by the browser routine 64 comprises a location such as a URL 48 in one of the files 36 , and if the expiry date 52 of the object 44 in the file 36 has not been exceeded, the object 44 stored in the file 36 is retrieved from within the browser cache 32 and is provided to the browser routine 64 for inclusion in the HTML document. In such a fashion, the amount of communication traffic between handheld electronic device 4 and the network 8 can be reduced. [0020] One exemplary implementation of such a browser cache 32 on the handheld electronic device 4 would additionally include storing on the server 12 or otherwise making available to the server 12 a mirror of the browser cache 32 . For example, if the network 8 receives a request from the browser routine 64 for a particular HTML document that may be obtainable from the network 8 , the server 12 may analyze the obtained HTML document and determine whether or not it includes one or more URLs from which may be obtained objects that should be included in the HTML document. The server 12 may determine from its mirror of the browser cache 32 whether or not the object which is available at a given URL might already be stored in the browser cache 32 . If the object is not already stored in the browser cache 32 , the server 12 will request the object from the URL and will send the object to the handheld electronic device 4 , typically in conjunction with the sending of the HTML document from the server 12 to the handheld electronic device 4 . On the other hand, if the object from the indicated URL is already available in an unexpired condition in the browser cache 32 , the object is not at that time requested from the URL. In accordance with the disclosed and claimed concept, the mirror of the browser cache 32 is advantageously updated whenever the browser cache 32 changes. [0021] Whenever a browser session is initiated, a data table 68 , such as is depicted generally in FIG. 2 , is generated and is stored in the memory 28 . The data table 68 includes a number of first objects 72 and a number of second objects 76 stored therein. Each first object 72 comprises a file name 40 , which is the file name 40 of a file 36 in the browser cache 32 . Each first object 72 has associated therewith a second object 76 that comprises the location, i.e., the URL 48 in the present example, of the same file 36 . In the depicted exemplary implementation, the file names 40 are each stored in the first objects 72 as a hash of the file name 40 in order to reduce storage requirements and to facilitate processing. [0022] After the data table 68 has been created, a hash of each URL 48 in the second objects 76 is provided to the server 12 to create on the server 12 the mirror of the browser cache 32 . It may additionally be desirable to provide, in conjunction with each hash of a URL 48 , the expiry date 52 of the object 44 that was obtained from the same URL 48 , as is stored in one of the files 36 . [0023] Whenever the contents of the browser cache 32 undergo a change, the change is advantageously communicated to the server 12 so that the mirror on the server 12 of the browser cache 32 can be updated in order to enable the mirror of the browser cache 32 to accurately reflect the contents of the browser cache 32 on the handheld electronic device 4 . In response to a change in the browser cache 32 , the API 60 is configured to provide to the browser routine 64 the name of the file 36 in the browser cache 32 that has undergone the change. The API 60 also provides a notification of the type of change undergone by the file 36 of which the file name 40 has just been provided. The various notifications include a CREATE notification, an UPDATE notification, a DELETE notification, and a RENAME notification indicating that a particular file has been created, updated, deleted, or renamed, respectively. In the case of a RENAME notification, typically two file names 40 are provided, i.e., the initial file name 40 of the file 36 , as well as a new name for the same file 36 . [0024] It is noted, however, that merely providing the file name 40 of the file 36 that has undergone a change does not itself provide the URL 48 of the same file 36 , and such URL 48 cannot be obtained directly from the operating system 56 or the API 60 . The browser routine 64 is advantageously configured to obtain in other fashions the particular URL 48 of the file 36 in the browser cache 32 that has undergone the change. [0025] FIG. 3 generally depicts an exemplary flowchart depicting certain aspects of the way in which the server 12 is able to have a substantially continuously updated mirror of the browser cache 32 that is stored on the handheld electronic device 4 . As indicated above, upon initiation of a browser session by the browser routine 64 , the data table 68 is generated, as at 104 . At least a portion of the data table 68 is then supplied, as at 108 , to the server 12 . As indicated above, typically what is supplied to the server 12 is a hash of each URL 48 stored in the second objects 76 , along with the corresponding expiry date 52 . [0026] The browser routine 64 receives from the API 60 a notification, as at 112 , that a certain file 36 has undergone a change. Specifically, the file name 40 of the file 36 that has undergone the change, as well as a notification type are provided to the browser routine 64 . As indicated above, the four exemplary types of notifications are CREATE, UPDATE, DELETE, and RENAME. [0027] It is then determined, as at 116 , whether the notification was a CREATE notification. If not, it is then determined, as at 120 , whether the notification was a DELETE notification or an UPDATE notification. If not, the notification is ignored, as at 124 . However, if it was determined at 120 that the notification was either DELETE or UPDATE, the browser routine 64 obtains, as at 128 , from the data table 68 the URL 48 that is associated with the received file name 40 . More specifically, the data table 68 is consulted to identify the first object 72 which has stored therein a file name 40 that is the same as the received file name 40 . The second object 76 associated therewith is consulted to obtain the URL 48 stored therein. The URL 48 and other appropriate data are then supplied, as at 132 , to the server 12 . The data table 68 is then updated, as at 136 , to reflect the change that was notified at 112 , assuming that the notification was not ignored at 124 . [0028] With more particular regard to the additional data that can be supplied, as at 132 , to the server, it is noted that a notification which is a DELETE notification will generally result in supplying to the server 12 a hash of the URL 48 of the deleted file 36 , along with a notification that the change was a DELETE. The server 32 will previously have stored in its mirror of the browser cache 32 a hash of the URL 48 in the file 36 that is being deleted. Upon receiving the update transmission, as at 132 , the server will delete from its mirror of the browser cache 32 the hash of the URL 48 of the deleted file 36 . [0029] However, if the notification received at 112 was an UPDATE notification, updated data such as an updated expiry date 52 typically will be supplied, as at 132 , to the server 12 . Such updated data can be obtained in any of a variety of ways. Such updated data can even be obtained from the server 12 . [0030] For instance, the browser routine 64 may make a request of the server 12 for a specific HTML document. After receiving the request, the server will obtain, such as from the network 8 , the requested HTML document. The obtained HTML document may comprise one or more URLs, and the server 12 may determine from its mirror 12 of the browser cache 32 that the object available at a particular indicated URL is already stored on the handheld electronic device 4 as an object 44 in the browser cache 32 . However, the server 12 may also determine that the expiry date 52 of the object 44 has been exceeded, i.e., the object 44 has expired. In this regard, the browser cache 32 may be configured to delete files 36 when the expiry date 52 of the object 44 stored therein has been exceeded. On the other hand, however, the browser cache 32 may be configured such that the file 36 having stored therein an exceeded expiry date 52 is not necessarily deleted, but the object 44 stored therein is updated if requested after expiration of the expiry date 52 . [0031] The server 12 might make the determination that the expiry date 52 of the object 44 has been exceeded by first creating a hash of the URL contained within the obtained HTML document. The server 12 will then identifying in its mirror of the browser cache 32 the matching URL hash, and determining whether the expiry date 52 that is associated with the identified matching URL hash has been exceeded. [0032] If the server 12 determines that the expiry date 52 of an object 44 stored in the browser cache 32 has been exceeded, the server 12 may make a new request of the object from the URL. A header of the request may include an instruction to the URL that it provide the object stored at the URL only if the object has changed since being stored in the browser cache 32 . If it turns out that the object is not changed, the URL may simply return to the server 12 an updated expiry date. [0033] The updated expiry date will then be transmitted to the handheld electronic device 4 , and the operating system 56 will store the received expiry date as an updated expiry date 52 in the corresponding file 40 . Such an update will cause the API 60 to generate an UPDATE notification which will be received by the browser routine 64 , as at 112 . As such, when at 132 the browser routine 64 supplies to the server 12 the URL 48 and appropriate additional data, part of the additional data will be the updated expiry date 52 that has already been stored in the file 36 within the browser cache 32 . [0034] If the URL returns to the server 12 a different object than is stored in the browser cache 32 , the same URL will likely additionally provide an updated expiry date. The server then would transmit to the handheld electronic device the updated object and updated expiry date, and these would both be saved in the file 36 , with the API 60 generating an UPDATE notification at 112 , and with the updated expiry date 52 being supplied, as at 132 to the server 12 . [0035] If at 116 it is determined that the notification was a CREATE notification, processing continues to 144 where the browser routine 64 requests from the operating system 56 the name of a file 36 that comprises a URL 48 which was the subject of a recent request by the browser routine 64 . That is, during a browsing session the browser routine 64 makes a number of browser requests of the server 12 . The fact that a particular URL request was made by the browser routine 64 does not indicate whether or not a file 36 having the particular URL stored therein was recently added to the browser cache 32 since it is possible that the object 44 which would otherwise be available at the URL on the network was already stored in the browser cache 32 . However, the browser routine 64 maintains a list of recent URL requests. As such, at 144 the browser routine 64 requests of the operating system 56 the name of a file 36 having a particular URL 48 stored therein. The particular URL 48 typically will be the URL that was the subject of the most recent URL request by the browser routine 64 . [0036] In response to the request at 144 , the operating system 56 may return a file name 40 or may return nothing. It is then determined, as at 148 , whether the returned file name 40 , if any, and the file name 40 that was generated as part of a notification at 112 are the same. If they are not the same, or if no file name was returned in response to the request at 144 regarding a particular URL, processing returns to 144 where additional requests are made for additional URLs that were the subject of recent URL requests. In this regard, the URLs employed in the requests at 144 typically will be made in reverse chronological order, i.e., the most recent URL will be the subject of the first request at 144 , and if the result at 148 is “no”, a successive request at 144 will be made with respect to the URL that was next most recently requested by the browser routine 64 , and so forth. [0037] In response to one of the requests at 144 , the operating system 56 will return a file name 40 that matches the file name 40 that was generated as part of the notification at 112 . In such a circumstance, a hash of the URL that was the subject of the successful request is supplied, as at 132 , to the server 12 . The data table 68 is then updated, as at 136 . [0038] As a general matter, the API 60 is capable of generating numerous notifications that may be in excess of what is necessarily or desirably handled by the routines on the handheld electronic device 4 . For instance, the API 60 may generate numerous notifications in response to a single event. By way of example, it is noted that an updating operation on the handheld electronic device 4 may generate five separate notifications as follows: [0039] 1) the device may create a new file, thus resulting in a CREATE notification; [0040] 2) the device may update the new file by writing into the new file the contents of an old file, thus generating an UPDATE notification; [0041] 3) the device may append any changes, i.e., edit, the new file, thus resulting in an UPDATE notification; [0042] 4) the device may delete the old file, thus resulting in a DELETE notification; and [0043] 5) the device may rename the new file to have the name of the old file and to have the attributes of the old file, thus resulting in a RENAME notification. [0044] In essence, the only meaningful change to the browser cache 32 was the updating of the old file, but the way in which the updating occurred resulted in the generation of five notifications, only one of which is particularly meaningful, such as to the browser routine 64 . On the other hand, a routine other than the browser routine 64 might find more than one of the five notifications to be useful or relevant. [0045] In accordance with the disclosed and claimed concept, the notifications generated by the API 60 are advantageously subjected to one or more predetermined criteria or algorithms to determine whether or not one or more of the notifications can be ignored. It is noted that the various predetermined criteria, i.e., algorithms, likely will be specific to a given routine on the handheld electronic device 4 . That is, what may be an unnecessary or irrelevant notification to one routine might be relevant or desirably noted by another routine. [0046] The browser routine 64 is provided herein as an exemplary routine to which certain notifications generated by the API 60 may desirably be ignored. It is reiterated that certain of the algorithms may be usable in conjunction with other routines than the browser routine 64 , and that other algorithms may be unusable with routines other than the browser routine 64 . Also, other routines may have other predetermined criteria or algorithms for use in determining whether certain of the notifications can be ignored by the routines. [0047] One of the predetermined criteria, i.e., one algorithm, is to determine whether or not a notification relates to a particular type of file. For instance, a certain routine may find relevant only those notifications that relate to a file having a suffix “.txt”. As is mentioned above, the API 60 may generate a number of notifications that each comprise the type of notification, i.e., CREATE, UPDATE, DELETE, or RENAME, as well as the file name 40 of a file 36 that was the subject of the notification. If the particular routine finds relevant only those particular notifications that relate to a “.txt” file, any notification that relates to a file that is of a type other than a “.txt” file will be ignored. [0048] However, a RENAME notification from a file type that the particular routine does not consider relevant into a file name that the routine does consider to be relevant will be ignored and instead treated as a CREATE notification of the file name that the routine considers to be relevant. For instance, a RENAME notification of a file 36 from filename.tmp to filename.txt will be treated as a CREATE notification of filename.txt. Similarly, a RENAME notification from a file type that the particular routine considers to be relevant into a file name that the routine does not consider to be relevant will be ignored and instead treated as a DELETE notification of the file name that the routine considers to be relevant. [0049] It is noted that ignoring a notification can occur in two fashions. In the first fashion, ignoring a notification can simply mean paying no attention to the notification, with no subsequent action. The other fashion of ignoring a notification can occur by paying no attention to the notification that was received, and rather treating the notification as a different notification. The different notification can be of a different type and/or can be as to a different file. [0050] Notifications typically are received from the API 60 as a sequence, i.e., a plurality of notifications are sequentially received from the API 60 . The exemplary browser routine 64 may initiate analysis of the notifications, i.e., for the purpose of potentially ignoring certain of the notifications, in response to any of a variety of events. For instance, the browser routine 64 might employ a timer which is reset upon each receipt of a notification. The timer may be set to a particular period of time, i.e., a period of two seconds, or another appropriate time period. If the timer expires without detecting another notification from the API 60 , the analysis of the series of notifications may be initiated. On the other hand, notifications may be identified as being in discrete “bunches” which are analyzed together. Other triggering events can be envisioned. [0051] It is noted, however, that an analysis of a relatively greater number of notifications will have a more appropriate result than an analysis of a relatively lesser number of notifications. This is due, at least in part, to the nature of the analysis. As a general matter, each notification is analyzed as being a “current” notification and is analyzed in the context of a “following” notification in the sequence. That is, notifications are analyzed in pairs. In the examples set forth herein, the “following” notification is a sequentially next notification immediately following the “current” notification, but it is noted that the “following” notification could, in appropriate circumstances, be sequentially later than the immediately next notification after the “current” notification. [0052] An exemplary set of criteria, i.e., algorithms, are set forth in the accompanying Table 1 below: TABLE 1 “Following” Notification RENAME from CREATE file UPDATE file DELETE file “filename2.txt” to “filename1.txt” “filename1.txt” “filename1.txt” “filename1.txt” “Current” CREATE file Ignore the CREATE Ignore the Keep both Keep both CREATE Notification “filename1.txt” notification of UPDATE CREATE and and RENAME “filename1.txt” notification DELETE notifications notifications UPDATE file Ignore the CREATE Ignore the Keep both Keep both UPDATE “filename1.txt” notification of UPDATE UPDATE and and RENAME “filename1.txt” notification DELETE notifications notifications DELETE file If the notification before Keep both Ignore one Replace these 2 “filename1.txt” the DELETE was a DELETE and DELETE notifications with: CREATE or UPDATE, UPDATE notification DELETE filename2.txt then, ignore this notifications and UPDATE DELETE and CREATE filename1.txt of “filename1.txt”. Otherwise, replace these 2 notifications with an UPDATE notification for “filename1.txt”. RENAME from Keep both RENAME Keep both Keep both Ignore one RENAME “filename2.txt” and CREATE RENAME and RENAME and notification to notifications UPDATE DELETE “filename1.txt” notifications notifications [0053] As can be seen from Table 1, if either a CREATE notifications or an UPDATE notification (as a “current” notification) is followed by either a CREATE notification or an UPDATE notification (as a “following” notification) as to the same file, the “following” notification is ignored. For other routines, i.e., other embodiments, the algorithm might be to ignore either the “current” notification or the “following” notification, and to treat the non-ignored notification as an UPDATE notification. [0054] As can further be seen from Table 1, if either a CREATE notification or an UPDATE notification is followed by either a DELETE notification or a RENAME notification that indicates a deletion of the same file or a renaming of another file to the same file, both notifications may be kept, i.e., not ignored. This may be based, at least in part, upon the unlikelihood of detecting from the API 60 such a pair of notifications. Table 1 thus suggests that if such an unlikely pair of notifications is detected, the notifications are not ignored. As an alternative, another routine might choose to ignore both notifications in such a circumstance. [0055] If two sequentially consecutive notifications are precisely the same, i.e., of the same nature and as to the same file, another algorithm might be to ignore one of the two notifications. With other routines, however, possibly neither notification is ignored due to the unlikeliness of receiving such a pair of notifications. [0056] In the circumstance of a DELETE notification followed by a CREATE notification as to the same file, it is determined whether or not the notification that preceded the DELETE notification was either a CREATE notification or an UPDATE notification. If so, the current DELETE and the following CREATE notifications are ignored. However, if the notification preceding the DELETE notification was neither a CREATE nor an UPDATE notification, the current DELETE notification and the following CREATE notification are ignored and are treated as a single UPDATE notification as to the same file. For other routines, the same result can be obtained when the current DELETE notification is followed by an UPDATE notification rather than the aforementioned CREATE notification. [0057] As can further be seen from Table 1, if a DELETE notification as to a particular file is followed by a RENAME notification renaming another file to the name of the particular file, such notifications are replaced with a DELETE notification as to the another file and an UPDATE notification as to the particular file. In effect, the two original notifications are ignored, and are treated as two different notifications. Alternatively, the two notifications could be treated as a DELETE notification as to the another file and a CREATE notification as to the particular file. The two different notifications can then be analyzed in the context of the other notifications in the sequence of notifications being analyzed in order to possibly ignore one or more of these notifications or other notifications in the series. [0058] As can further be seen from Table 1, a RENAME of one file to the name of another file which is followed by a CREATE, an UPDATE, or a DELETE notification as to the another file will result in neither notification being ignored. In other embodiments, however, one or more of such notifications could potentially be ignored, depending upon the needs of the routine. [0059] As an example, a sequence of notifications to be analyzed may be as follows: CREATE filename.tmp UPDATE filename.tmp UPDATE filename.tmp UPDATE filename.tmp UPDATE filename.txt DELETE filename.txt RENAME filename.tmp to filename.txt UPDATE filename.txt. [0060] As a first step we may ignore the notifications for files of a type about which the browser routine 64 is not concerned. For example, all notifications relating to a file name other than a “.txt” file will be ignored. However, the RENAME notification from filename.tmp to filename.txt will be treated as a CREATE notification of filename.txt. This leaves the following: UPDATE filename.txt DELETE filename.txt CREATE filename.txt UPDATE filename.txt. [0061] When the first two notifications are considered as a “current” and a “following” notification, Table 1 indicates that an UPDATE notification followed by a DELETE notification as to the same file results in both notifications being kept. If the aforementioned DELETE notification is now considered a “current” notification and is analyzed in the context of the subsequent CREATE notification being a “following” notification, Table 1 indicates that a DELETE notification that is preceded by an UPDATE notification and followed by a CREATE notification as to the same file name, will result in the DELETE and the following CREATE notifications both being ignored. [0062] In the circumstance of a “following” notification being ignored, the next “current” notification to be analyzed will be the most immediately preceding notification that has not yet been ignored. Thus, the first UPDATE notification will again be considered as a “current” notification, and will be considered to be followed by the second UPDATE notification. Table 1 indicates that an UPDATE notification followed by another UPDATE notification as to the same file will result in the second UPDATE notification being ignored. [0063] In the context of the exemplary browser routine 64 , therefore, seven of the eight notifications in the exemplary notification sequence above were ignored. As a result, the method indicated for example by the flowchart in FIG. 3 would need to be executed only once, i.e., for the sole remaining UPDATE notification, rather than executing the same routine eight separate times. This advantageously saves executing and power resources. [0064] Such a method is depicted generally in the exemplary flowchart of FIG. 4 . For instance, the browser routine 64 listens, as at 204 , for notifications from the API 60 . It is determined, as at 208 , whether or not a notification was received. If a notification was received, the timer is reset, as at 212 , and processing returns to 204 where the browser routine 64 listens for further notifications. If at 208 it is determined that no notification was received in the preceding listening operation at 204 , it is then determined, as at 216 , whether or not the timer has expired. If not, processing returns to 204 where further listening occurs. [0065] In this regard, it can be understood that the exemplary steps 204 , 208 , 212 , and 216 form a loop that is repeated at certain intervals, perhaps as often as the processor can execute the loop. Once the timer has expired without having received an additional notification, processing continues to 220 whether it is determined whether or not any of the notifications meet any of the predetermined criteria, i.e., the criteria that are predetermined for the routine performing the listening at 204 or for which the notifications are being detected. If no notifications meet the predetermined criteria, the notifications are acted upon, as at 224 . Such notifications may be acted upon by being stored, by initiating other processing, or in other fashions. [0066] If, however, at 220 it is determined that some of the notifications meet one or more of the predetermined criteria, processing continues at 228 where certain of the notifications are ignored and, as appropriate, may be treated as being different notifications. Processing thereafter continues at 224 where the remaining notifications are acted upon. [0067] With further regard to the operations at 220 , it is understood that any of a variety of criteria, i.e., algorithms, can be employed depending upon the needs of the particular routine in question. As such, algorithms in addition to those set forth herein can be employed without departing from the present concept. [0068] While specific embodiments of the disclosed and claimed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed and claimed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.

An improved handheld electronic device includes an Application Programming Interface (API) that generates various notifications in certain circumstances. The handheld electronic device provides an improved method of employing the notifications to enable another device to reflect a change to a browser cache on the handheld electronic device.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the priority under 35 U.S.C. §119(a) of German Utility Model Application 20 2011 103 105.9 filed Jul. 12, 2011, the disclosure of which is expressly incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention Embodiments of the invention relates to a device for determining the wear of a carbon ceramic brake disk. The device includes at least one coil for generating a magnetic field in the brake disk and for detecting an eddy current in the brake disk. 2. Discussion of Background Information A “carbon ceramic brake disk” is a brake disk comprising a carbon ceramic, wherein the carbon ceramic comprises a ceramic matrix as well as carbon fibers embedded in the matrix. In such carbon ceramic brake disks an oxidation of the carbon fibers and therefore wear occurs due to high operating temperatures. This wear cannot be reliably recognized by mere optical inspection. An improved recognition of wear is achieved by inductive methods of measurement. The principle used in this type of measurements is based on eddy current damping; either using two coils (EP 1 387 166) operating continuously, or one or two coils in pulsed operation (DE 10 2008 051 802). The disclosures of EP 1 387 166 and DE 10 2008 051 802 are expressly incorporated by reference herein in their entireties. In these documents the excellent correlation between the inductive measurement and a gravimetric determination of the wear is disclosed. A conventionally traded profometer (www.proceq.com) is used as measuring device. Using these types of techniques, it is not necessary to disassemble the brake disk for measurement. It is also noted that the measuring values are independent on soiling and the presence of liquids. The by far largest problem of such procedures lies in the fact that, due to the unavoidable inhomogeneity of the material, the measured values can differ strongly as a function of location (variations up to 100% are observed). A further variation is caused by the venting ducts extending within the disk. A conventional device can, upon a dislocation of a few millimeters, display a value that deviates by more than 10%. Since the drop of the measured value between a new and a worn disk is at approximately 40 to 50%, such a location dependence is greatly disadvantageous for a measurement. DE 10 2008 051 802 describes a positioning technique by a gauge and mechanical positioning device, which, however, is found to non-viable. Further it must be noted that reliable measuring values can only be recorded when the measuring device lies exactly against the disk, which leads to additional requirements regarding the shape of the device if the same is to be operated by hand at a location of service. A further disturbing factor is due to the metallic elements, such as the caliper, axle shaft and fender, present around a built-in brake disk. SUMMARY OF THE EMBODIMENTS Therefore, embodiments of the invention are directed to a device of the type mentioned above that allows a more reliable measurement of the wear. According to embodiments, the device for determining wear in a carbon ceramic brake disk includes a coil arrangement having at least one coil adapted and structured to generate a magnetic field in the brake disk and for detecting an eddy current in the brake disk. The coil arrangement has an arcuate measuring area. In this context, the “measuring area” is the area in a measuring plane (i.e., in a plane parallel to the plane of the coils) that is reached by the field of the coil or coils during the measurement. In particular, the measuring area includes those locations in the measuring plane where the flux of the magnetic field generated by the coil(s) is at least 50% of a maximum value of the flux of the magnetic field in the measuring plane. By the measuring area in accordance with the embodiments, a non-local measurement can be carried out over an extended region of the brake disk, which makes the measurement less sensitive to local inhomogeneities of the carbon ceramic. Advantageously, the coil arrangement comprises at least three coils, in particular more than three coils, as well as a drive for generating, by means of the coils, a magnetic field in the measuring area. Embodiments of the invention are directed to a device for determining wear in a carbon ceramic brake disk. The device includes a coil arrangement having at least one coil structured and arranged to generate a magnetic field in the brake disk and to detect an eddy current in the brake disk, and an arcuate measuring area. According to embodiments, the arcuate measuring area may be positionable in a ring having a radial width smaller than 2 cm and an inner radius between 10 and 15 cm, and a length tangentially along the ring of at least 8 cm. In accordance with other embodiments of the invention, the at least one coil can include at least three coils structured and arranged to generate a magnetic field in the measuring area. Further, the at least one coil may include more than three coils structured and arranged to generate a magnetic field in the measuring area. The device can also include a common carrier plate on which the coils. The coils can be formed by conductive leads on the carrier plate. Moreover, each coil can extend around a center and the centers of the coils may be arranged on an arcuate curve. The centers of the coils can be arranged on a segment of a circle. Still further, each coil may extend around a center and the centers of the coils may be arranged on at least two arcuate, parallel curves. The centers of the coils can be arranged on at least two segments of concentric circles. The device may also include a common carrier plate on which the coils are arranged, and the common carrier plate one of forming a measuring surface or abutting on an inner side of a wall section forming the measuring surface. Further, each two neighboring coils on different curves can be poled anti-parallel to each other. According to still other embodiments of the instant invention, the device may further include a voltage supply and a driver. The driver can be structured and arranged to connect the coils, in parallel to each other, to the voltage supply. The driver can be structured and arranged to disconnect the coils from the voltage supply and to sum inductive voltages generated over the coils after disconnecting the coils from the voltage supply. In accordance with further embodiments of the invention, mutually neighboring coils can be poled anti-parallel to each other. According to still other embodiments, the device may also include a housing and stops arranged on the housing being structured and arranged to radially abut against the brake disk. The device can also include a measuring surface structured and arranged to abut against a front side of the brake disk. The stops can include projections extending transversally to the measuring surface. The projections may include rollers. The device can also include a light source for generating a light field as a positioning aid. The light source and the stops can be mutually arranged to generate a light strip on a front face of the brake disk upon abutting the device against the brake disk. According to still other embodiments, the device can also include a light source structured and arranged to generate a light field as a positioning aid. In accordance with still yet other embodiments of the present invention, a diameter of the at least one coil can be between 10 and 15 mm. Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein: FIG. 1 shows a first perspective view of the device; FIG. 2 shows a view of the device abutting against a brake disk; FIG. 3 shows a representation of the arrangement of the measuring coils; FIG. 4 is a schematic representation of the measuring area on the brake disk; FIG. 5 shows a measured value as a function of the angle; FIG. 6 is a partial block circuit diagram of the device; and FIG. 7 shows a device with two rows of measuring coils. DETAILED DESCRIPTION OF THE EMBODIMENTS The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice. The device illustrated in FIGS. 1 and 2 include a housing 1 with a measuring surface 2 intended to abut against a front face 3 of brake disk 4 during the measurement. Further, stops 5 , 6 are provided on housing 1 to extend transversally, in particular, perpendicularly, to measuring surface 2 . Stops 5 , 6 are arranged to radially abut housing 1 against an outer edge 7 of brake disk 4 , i.e., they are used to radially align housing 1 with respect to brake disk 4 . Stops 5 , 6 are designed as projections that extend over measuring surface 2 . Advantageously, exactly two such projections are employed in order to ensure a defined radial abutment on brake disk 4 . The device further includes a display 8 , advantageously arranged on a side of housing 1 that is opposite to measuring surface 2 so that it can be seen by the user. When the device is abutting correctly against brake disk 4 , a side 9 of housing 1 is arranged to face the axle of brake disk 4 . Further, side 9 includes a light source 11 , which can include, e.g., a semiconductor laser having a light beam is extended in a direction perpendicular to front face 3 to form a planar light field 12 . Planar light field 12 can serve as a positioning help because light source 11 and stops 5 , 6 should preferably be mutually aligned so that, when the device correctly abuts against brake disk 4 , a strip of light 13 is created on front face 3 . The user can use strip of light 13 for azimuthally aligning the device in a defined manner with respect to one or more marks 14 arranged on brake disk 4 . This solution requires no additional mechanical marker and is suited for all disk sizes. For better identification, light source 11 may be modulated in brightness. The user can place housing 1 against brake disk 4 in the manner shown in FIG. 2 , where the projections 5 , 6 align the device radially and measuring surface 2 provides an axial alignment. To move the device to the correct azimuthal angle position, the user moves it along the circumference of brake disk 4 . To simplify this motion, projections 5 , 6 can be formed by rollers, e.g., rotatable cylinders, which roll along outer edge 7 of brake disk 4 . As has been mentioned, the measurement is carried out by one or more coils. FIG. 3 shows an advantageous coil arrangement with several coils 15 . In this embodiment, coils 15 are arranged side by side in a row, such that their centers lie along an arcuate curve 16 , in particular a segment of a circle. The center of a circular coil is understood to be the axis that the coil is wound around. Coils 15 form an arcuate measuring area 18 , as it is shown in dashed lines in FIG. 4 . Measuring area 18 lies within a ring 19 between two concentric circle lines 20 , 21 . Radial width D of the ring (i.e., the distance between circle lines 20 , 21 ) is smaller than 2 cm. Length L of measuring area 18 measured tangentially along the ring is at least 8 cm. Inner radius R of ring 19 lies between 10 and 15 cm. With a measuring area 18 of this type, a substantial region of a conventional brake disk can be reached, without metallic parts of the attachment or edge regions of the brake disk falling within measuring area 18 . Instead of a single row of coils 15 , it is also possible to use at least two rows of coils 15 . This is illustrated in FIG. 7 , where the two rows of coils 15 are arranged on two parallel, arcuate curves 16 ′, 16 ″, in particular, on two segments of concentric circles. Advantageously, each two neighboring coils 15 arranged on different curves are poled anti-parallel, as it is shown by the signs + and − in FIG. 7 . In this manner, the field of one coil is deflected into the respective neighboring coil, so that it extends through a substantial volume of brake disk 4 without extending very deeply into brake disk 4 . This allows preventing the field from exiting through the opposite side of brake disk 4 , where it might be affected by metal parts. In principle, also in the embodiment of FIGS. 3 and 4 , each two neighboring coils can be poled anti-parallel. However, it has also been found that the use of anti-parallel poled coils in an arrangement with two rows of coils according to FIG. 7 is particularly advantageous. The term “poled anti-parallel” as used in the embodiments is to be understood to mean that the fields generated by the two coils are anti-parallel to each other. This can be achieved, e.g., by winding the two coils in opposite winding directions and by sending currents of equal phases through them, or by winding the two coils in the same winding direction and by sending oppositely phased currents through them. The coils 15 shown in FIG. 3 may be advantageously arranged on a common carrier plate 25 , which simplifies their mounting and mutual alignment. Advantageously, they are designed as concentric conducting leads on carrier 25 , implemented as a multi-layer printed circuit. In the embodiment shown in FIG. 3 , carrier plate 25 lies against a wall section 26 of housing 1 that forms measuring surface 2 . Advantageously, carrier plate 25 is laminated to wall section 26 . Alternatively, carrier plate 25 can form the outer wall of housing 1 and therefore measuring surface 2 itself. Both these embodiments allow positioning of coils 15 close to and in very well defined spatial relation relative to the surface of brake disk 4 . In particular, the distance between coils 15 and the sample does not vary when the force pressing the one against the other changes. This is important because a variation of the distance by only a few tenths of a millimeter can lead to very large signal variations. Coils 15 have a diameter that corresponds approximately to the half thickness of the sample such that their field extends sufficiently deep into the brake disk 4 without a substantial part of the field exiting from the opposite side of brake disk 4 . In order to fulfill these requirements for typical brake disks, an advantageous diameter of coils 15 is in a range between 10-15 mm. If the coils are non-rotationally symmetric, this is the diameter tangential to the brake disk if the measuring device is applied in its measuring position against brake disk 4 . A review of FIG. 5 shows that the selected geometry satisfies the requirements. The wiggly line shows the position dependence of the signal when measuring with a single coil whose diameter corresponds approximately to the disk thickness. A part of the modulation is caused by the venting channels—overlaid and non-periodic are variations due to the natural inhomogeneity of the composite. The smoothed curve is created when sampling with the device described here. The vertical axis shows the measuring value, in linear units, the horizontal axis the angle or azimuthal position of the device along the outer edge of the brake disk 4 . FIG. 6 shows a possible embodiment of the coil circuit. Accordingly, a driver 30 is provided, which controls the operation of coils 15 and generates a magnetic field in measuring area 18 via coils 15 . An electronic switch 31 is attributed to or associated with each coil, i.e., coils 15 can, by closing switches 31 , be connected, parallel to each other and to the supply voltage from a voltage source 32 . This parallel configuration allows using a voltage source 32 with low voltage and without voltage converter, such as a simple battery. When switches 31 are interrupted, coils 15 are disconnected from the voltage supply and an inductive voltage is generated over each coil due to the eddy currents in brake disk 4 . These inductive voltages are added computatively or electrically by driver 30 . In this manner, a comparatively strong signal is generated even if only a low supply voltage is used. Advantageously, as shown in FIG. 1 , the device has an interface 39 for exchanging data with external equipment, e.g., in order to generate a protocol of the measurements that have been carried out. Further, one or more buttons 40 can be arranged on the device for storing and/or marking a current measuring value. In principle, it is also possible to equip the device with a single coil only, which has an arcuate cross section. However, as such a coil has a high inductance, it needs more power and is slower in operation. In addition, its field reaches deeply, which gives rise to a risk that components arranged behind the brake disk may be included in the measurement. For these reason, it is advantageous to use several coils, and in particular more than three coils. It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.

Device for determining wear in a carbon ceramic brake disk. The device includes a coil arrangement having at least one coil structured and arranged to generate a magnetic field in the brake disk and to detect an eddy current in the brake disk, and an arcuate measuring area.

BACKGROUND OF THE INVENTION The present invention relates to the combination of an automatic spinning machine of the type having a plurality of spinning positions each adapted for receiving a supply of sliver delivered from a respective sliver cam with an apparatus for replacing empty sliver cans at the spinning positions of the spinning machine with full replacement sliver cans. It is known to transport cans filled with sliver on a traveling conveyor belt from which the cans may be manually transferred to a sliver processing machine, such as an open end spinning machine or another automatic spinning machine. It is accordingly an object of the present invention to provide an apparatus by which empty sliver cans at the spinning positions of a spinning machine may be automatically replaced with full sliver cans in order to improve the efficiency of the spinning operation. SUMMARY OF THE INVENTION Briefly summarized, the present invention provides a sliver can replacement apparatus arranged in combination with an automatic spinning machine and having an arrangement for transporting sliver cans alongside the spinning positions of the spinning machine with certain locations on the transporting arrangement being provided for supporting full sliver cans and other locations on the transporting arrangement being provided for supporting empty sliver cans at the same time. An automatic can replacement arrangement is also provided for traveling movement alongside the spinning positions of the spinning machine in association with the can transporting arrangement, the can replacement arrangement including a sensing arrangement for recognizing and distinguishing full sliver cans and empty sliver cans on the transporting arrangement and an associated can transferring arrangement for transferring empty sliver cans from the spinning positions of the spinning machine to the empty can locations of the transporting arrangement and for transferring full sliver cans from the full can locations of the transporting arrangement to the spinning positions of the spinning machine. The traveling can replacement arrangement is operative, either during its traveling movement or when it is parked at a spinning position of the spinning machine, to recognize whether the sliver can in feeding operation at the spinning position has become completely depleted of its sliver supply or is imminently nearing complete sliver depletion. If the sliver can is already emptied so that the spinning position has ceased operation for such reason, the can replacement arrangement is operated immediately to perform a can replacement operation. On the other hand, if the sliver can is not yet completely emptied so that the spinning position is still operating, the can replacement arrangement may be adapted to cause the spinning operation to be interrupted and then to immediately initiate a can replacement operation even though a small amount of unused sliver will remain in the nearly emptied can. As will be understood, it is generally more advantageous in such instances to sacrifice a small quantity of sliver in order to minimize the period of time during which the spinning operation is interrupted at the spinning position than to postpone the can replacement operation until the sliver can has fully emptied and the spinning position has ceased operation for some period of time. In the preferred embodiment of the present invention, the can transporting arrangement includes a conveyor arranged for traveling movement along the spinning positions of the spinning machine, the conveyor having the full and empty can locations arranged thereon in a predetermined sequence at substantially equal spacings along the length of the conveyor. Importantly, the sensing arrangement is capable of recognizing unoccupied empty can locations on the conveyor whereat empty cans removed from the spinning positions of the spinning machine may be placed and also is capable of recognizing and distinguishing occupied full can locations on the conveyor from which full cans of sliver may be transferred to the spinning positions of the spinning machine from which empty cans have been removed. The transporting arrangement may include a guide track extending alongside the spinning positions of the spinning machine and a plurality of can supporting carriages coupled to one another and movably supported on the track for guided movement therealong. A traction arrangement is coupled to at least one of the carriages for advancing the carriages along the track. Depending upon the particular operating environment, each carriage may be relatively small having only a single location for supporting a sliver can or, alternatively, may be relatively large having two or more locations capable of supporting a sliver can. The traction arrangement may be of any suitable type, such as an endless cable, chain or similar means of applying a traction force to the carriages. Alternatively, a locomotive-type drive vehicle may be supported on the track in coupled engagement with the carriages for applying a traction force for traveling movement of the carriages along the track. According to a further aspect of the present invention, each full can location of the transporting arrangement includes a detectable indicator to reflect that the location is a full can location and each empty can location of the transporting arrangement similarly includes a detectable indicator to reflect that the location is an empty can location. Various types of such indicators may be utilized. For example, the can supporting carriages may be provided with optically recognizable features, such as differently colored indicator signs or the like. Alternatively, the carriages may be provided with studs, pins, recesses or the like which may be mechanically sensed by a feeler or a like sensory mechanism or implement. It is also contemplated that electronic or magnetic markings may be provided on the carriages. For example, the carriages or the cans carried thereon may be provided with magnets exhibiting different magnetic strengths or attached at different positions to the carriages or the cans for sensory identification in order to distinguish between different carriages and different cans. Thus, a magnetic strip may be applied at a certain height on full sliver cans and at a differing height or other position on empty sliver cans. In any embodiment, when an empty sliver can is refilled with sliver, the indicator means is appropriately changed, which may be accomplished automatically. According to another feature of the present invention, certain can supporting locations on the transporting arrangement may be designated for use only for supporting full sliver cans with the remaining locations on the transporting arrangement designated only for supporting empty sliver cans. Before initiating each can replacement operation, the sensing arrangement determines whether an empty can location is occupied. By way of example, alternating can supporting locations on the transporting arrangement may be designated for supporting empty sliver cans with the intervening locations designated for supporting full sliver cans. In such case, the sensing arrangement must determine for each alternate location whether the location is occupied. The can replacement arrangement is preferably guided at each opposite side of the transporting arrangement for traveling movement along the spinning machine and includes a gantry portion which extends over the transporting arrangement and the sliver cans supported thereon. A can manipulating arrangement is supported on the gantry portion for movement along a track or rail toward and away from the spinning positions of the spinning machine, the can manipulating arrangement including a selectively operable mechanism for grasping sliver cans on the transporting arrangement and at the spinning positions of the spinning machine for carrying out a can transferring operation therebetween. A can replacement arrangement of this type requires only a sufficiently small amount of space so that such an arrangement may be retrofitted to existing automatic spinning machines which are not equipped with an automatic can replacement apparatus. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partially schematic end elevational view of an automatic spinning machine in combination with an automatic sliver can replacing apparatus according to the preferred embodiment of the present invention. FIG. 2 is a top plan view of the sliver can transporting arrangement of the apparatus of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the accompanying drawing, one spinning position of an automatic open end spinning machine is indicated broadly at 1, it being understood that the spinning machine has a plurality of like spinning positions arranged side-by-side along the length of the machine. The spinning machine is of a conventional construction and operation and therefore need not be described and illustrated in detail herein. At each spinning position 1, a sliver 2 is delivered through a sliver guide fitting 50 into a spinning box 3 wherein the sliver is spun into a yarn 4 which is progressively withdrawn from the spinning box 3 and wound onto a cross-wound bobbin 5. The sliver 2 is supplied from a sliver storage can 6 supported on a foot portion 7 of the spinning machine frame 8 immediately below the spinning box 3. A sensor 9 is positioned to monitor the presence of the sliver 2 shortly in advance of the sliver guide fitting 50, the sensor 9 being operatively connected through electrical lines 10, 11 with a transmitter 12 to produce a can replacement signal whenever the sensor 9 recognizes the absence of the sliver 2, thereby indicating that the sliver can 6 has become empty. A sliver can conveyor formed by a plurality of wheeled carriages 17 coupled in series to one another is guided along the forward side of the spinning machine alongside the spinning positions 1 on a pair of guide rails 13, 14 which extend in parallel spaced relation along the spinning machine. A chain 18, preferably in endless form, is connected to the carriages 17 and to a suitable drive (not shown) to apply a traction force to the carriages 17 for actuating traveling movement of the carriages 17 along the rails 13, 14. Each carriage 17 provides a single can supporting location 19 at which one sliver can 20 may be transported by the carriage 17. The rails 13, 14 extend from a can loading station located at one end of the spinning machine to a can unloading station located at the opposite end of the spinning machine. The carriages 17 are coupled to one another at substantially equidistant spacings with the can supporting location 19 of every alternate carriage 17 being designated for supporting a full can of sliver, e.g. the can 20, and the can supporting location 19' of every intermediate carriage 17' being designated for supporting an empty sliver can. (See FIG. 2) Thus, at the can loading station, a full can of sliver 20 is placed on every alternate carriage 17 while every intermediate carriage 17' therebetween is left unoccupied so as to be available for receiving emptied cans to be removed from the spinning positions of the spinning machine. Each carriage 17 is provided with a coded indicator 21, preferably in the form of colored pins, the carriages 17 carrying full sliver cans 20 being provided with differently colored pins, e.g. black pins 21, from the carriages 17' designated for carrying empty sliver cans, which for example are provided with white pins 21' (FIG. 2). Each carriage has a substantially flat main body of a generally square or rectangular configuration rollably supported on the guide rails 13, 14 by four rollers disposed at the corners of the carriage body, only rollers 22, 23 being shown in the drawings. An automatic can replacement carriage assembly 24 is similarly supported for traveling movement alongside the spinning positions 1 of the spinning machine on another pair of guide rails 15, 16 extending in parallel spaced relation along the spinning machine at opposite sides of the rails 13, 14. The can replacement carriage assembly 24 includes a gantry portion 30 supported on a pair of spaced upright frame members 25, 25' to extend transversely over the guided path of travel of the carriages 17 at an elevation slightly above the cans 20 supported thereon. The frame member 25 is rollably supported on the guide rail 15 by a pair of flanged rollers 26, only one of which is shown in the drawing, and similarly the frame member 25' is rollably supported on the guide rail 16 by a pair of rollers 27, only one of which is shown in the drawing. A drive motor 28 is operatively connected to one of the rollers 27 for driving the can replacement carriage assembly 24 along the guide rails 15, 16. The drive motor 28 is operatively connected to a signal receiver 29 which is adapted to receive can replacement signals generated by the transmitters 12 associated with the spinning positions 1 of the spinning machine, whereby the motor 28 is operative to drive the can replacement carriage assembly 24 to a parked position at the spinning position 1 generating a can replacement signal in order to execute a can replacement operation at the spinning position. The can replacement carriage assembly 24 includes a can manipulating mechanism 32 supported for movement along the gantry portion 30 toward and away from the spinning machine along a horizontal guide rail 31 mounted to the gantry portion 30. The guide rail has a generally T-shaped cross-sectional configuration, the manipulating mechanism 32 having four guide rollers 40, 41, only two of which are shown in the drawing, positioned for rolling engagement with the guide rail 31 to support the manipulating mechanism 32 for movement therealong. The manipulating mechanism 32 is connected to an endless transmission chain or belt 34 which is trained about a pair of rollers 42, 43 to extend horizontally across the gantry portion 30 beneath the guide rail 31. The roller 43 is connected to a geared drive motor 44 to be driven selectively clockwise or counterclockwise for actuating reciprocal movement of the manipulating mechanism 32 back-and-forth along the guide rail 31 toward and away from the spinning machine as indicated by the directional arrow 45. The can manipulating mechanism 32 includes a pair of grasping arms 35 pivotable toward and away from one another as well as vertically movable, the grasping arms 35 being cooperatively configured for grasping the upper beaded edge of a sliver can. A program controller 33 controls actuation of the grasping arms 35 and the motor 44 to control the operational motions of the can replacement carriage assembly 24. The controller 33 is operatively connected with a pair of sensors 36, 37 through respective control lines 38, 39. The sensor 36 is mounted on the frame member 25' of the can replacement carriage assembly 24 in a disposition for recognizing the presence and absence of sliver cans at the can support locations 19 on the carriages 17. The sensor 37 is similarly mounted on the frame member 25' in a disposition directed toward the location of coded indicators 21 at the can support locations 19 on the carriages 17 for recognizing and distinguishing the indicators 21. The controller 33 is programmed for operation in response to the sensors 36, 37. The operation of the apparatus of the present invention may thus be understood. The drive motor 29 of the can replacement carriage assembly 24 is normally operated to drive the carriage assembly 24 back-and-forth along the guide rails 15, 16 until a sliver can in feeding operation at one of the spinning positions 1 of the spinning machine is emptied. The sensors 9 at the respective spinning positions 1 of the spinning machine continuously monitor the presence of the slivers 2 supplied to the respective spinning boxes 3 from the sliver cans 6 thereat. As soon as the sliver 2 at any given spinning position 1 is emptied from the supply can 6, the terminal end of the sliver 2 passes the sensor 9 at the spinning position whereupon the sensor 9 immediately recognizes the absence of the sliver 2 and instantaneously delivers a signal through the operating lines 10, 11 to the respective transmitter 12 associated with the particular spinning station 1. The transmitter 12, in turn, emits a can replacement signal to be received by the receiver 29 on the can replacement carriage assembly 24. For example, the transmitter 12 may be adapted to emit a light beam in a horizontal direction so as to be intercepted by the receiver 29 when the can replacement carriage assembly 24 passes adjacent the transmitter 12 during the normal traveling movement of the can replacement carriage assembly 24. The receiver 29 then operatively controls the drive motor 28 of the can replacement carriage assembly 24 to position it in a stationary parked disposition at the associated spinning position 1 wherein the receiver 29 continuously receives the light beam emitted by the transmitter 12. The traction chain 18 associated with the can supporting carriages 17 is driven intermittently by its associated drive to travel in a forward direction, i.e. from the can loading to the can unloading stations at the opposite ends of the spinning machine, by a distance equivalent to the spacing between successive can supporting locations on the carriages 17 and to remain at a standstill for a predetermined period of time between the intermittent actuations of the chain 18. Once the can replacement carriage assembly 24 is parked at a spinning position 1 requiring replacement of an empty can 6 with a full can 20, the controller 33 actuates the manipulating mechanism 32 to advance toward the spinning position 1 at a point in time at which the sensor 37 detects the presence of a coded indicator 21 designating the can supporting location 19 of the carriage 17 then immediately adjacent the can replacement carriage assembly 24 to be an empty can location and simultaneously the sensor 36 detects the absence of any can supported by such carriage 17. At such point in time, the chain 18 will have just moved the carriages 17 forwardly by one can supporting location to locate an empty can location immediately beneath the line of reciprocal movement by the grasping arms 35. Once the grasping arms 35 are fully advanced to the spinning position 1 into disposition immediately above the empty can 6, the controller 33 actuates the grasping arms 35 to pivot toward one another to engage the empty can 6 beneath its beaded upper edge 46 and to raise the can slightly from the supporting foot portion 7 of the spinning machine frame 8. The controller 33 maintains the manipulating device 32 in such disposition until the advancing chain 18 associated with the carriages 17 completes two more incremental carriage advancing cycles. Specifically, as aforementioned, alternate can supporting locations 19 on the carriages 17 are initially supplied with full cans of sliver 20 at the can loading station. Accordingly, when the chain 18 is actuated to advance the carriages 17 by another can supporting location 19, a full can 20 is positioned immediately adjacent the can replacement carriage assembly 24, whereupon the sensor 36 detects the presence of the full can 20 and the sensor 37 simultaneously detects a coded indicator 21 designating a full can of sliver. Upon the next succeeding advancement of the carriages 17 by the chain 18, another empty can supporting location 19 is brought into position immediately adjacent the can replacement carriage assembly 24 and, once again, the sensor 36 will detect the absence of a can while the sensor 37 detects the presence of a coded indicator 21 designating an empty can replacement location 19. Immediately thereupon, the controller 33 actuates return movement of the manipulating mechanism 32 away from the spinning station 1, the empty can 6 being carried by the gripping arms 35. Once the gripping arms 35 are disposed above the empty can supporting location 19, the controller 33 actuates the gripping arms to move away from one another releasing the empty can downwardly onto the empty can supporting location. Thereafter, the manipulating mechanism 32 moves further away from the spinning position 1 into a resting disposition, as shown in the drawing, to await the next advancing cycle of the carriages 17. Once the chain 18 advances the carriages 17 by another can supporting location 19, it will be understood that another full sliver can, e.g. the can 20, is brought into position immediately adjacent the can replacement carriage assembly 24. As soon as the sensor 36 recognizes the presence of the sliver can 20 and the sensor 37 simultaneously recognizes the presence of a coded indicator 21 designating that the can is a full sliver can, the controller 33 again actuates the manipulating mechanism 32 to travel toward the spinning position 1 until the gripping arms 35 are positioned immediately above the full sliver can 20, as indicated at position A in the drawing, whereupon the gripping arms 35 are moved toward one another to engage the upper beaded edge 47 of the full sliver can 20 and the gripping arms 35 are then raised slightly to lift the can 20 from the supporting carriage 17. Immediately thereafter, the controller 33 advances the manipulating mechanism 32 further toward the spinning position 1 until the gripping arms 35 are located immediately above the foot portion 7 of the spinning machine frame 8, as indicated at the position B in the drawing. The gripping arms 35 are then lowered slightly and moved away from one another to release the full can of sliver 20 onto the foot portion 7 of the spinning machine frame 8. In the interim, the next advancing cycle of the drive chain 8 for the carriages 17 is carried out, bringing the next succeeding empty can supporting location 19 into adjacent disposition to the can replacement carriage assembly 24. Once this incremental advancement of the carriages 17 is completed and the carriages 17 are at a standstill, which is determined by the sensor 37, the controller 33 again actuates movement of the manipulating mechanism 32 to return it to its initial resting position shown in the drawings. Thereupon, the controller 33 reactuates the drive motor 28 via the operating line 48 to cause the can replacement carriage assembly 24 to resume its traveling movement along the spinning machine or, as applicable, to direct the carriage assembly 24 to another spinning position 1 whose sliver supply can 6 has emptied in the meantime and therefore requires can replacement. At the spinning position 1 whereat a can replacement operation was just completed, the leading end 49 of the sliver in the full can is manually introduced into the sliver guide fitting 50 of the spinning box 3 by a machine operator, after which the spinning position 1 is restarted by the operator. It is also contemplated that the introduction of the leading end of sliver 49 may be performed by an automatic mechanism. While the can replacement carriage assembly 24 in the embodiment of the present invention herein described and illustrated is operable to actuate traveling movements of its manipulating mechanism 32 toward and away from the spinning machine during standstill phases of the intermittent advancement of the carriages 17, it is alternatively contemplated that the can gripping arms 35 may be arranged to pivot sufficiently upwardly when not grasping a sliver can so as to enable the manipulating mechanism 32 to travel back and forth across the carriages 17 and the cans supported thereon without any need to coordinate the traveling movements of the manipulating mechanism 32 with the standstill phases of the transport carriages 17. It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiment, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.

An automatic sliver can replacement apparatus is combined with an automatic spinning machine for replacing empty sliver cans with full sliver cans. Sliver supporting carriages are guided to travel along the spinning machine with full sliver cans being supported at alternating can locations on the carriages and intermediate can supporting locations being unoccupied for supporting empty sliver cans. Another carriage movable along the spinning machine supports a can manipulating mechanism equipped with sensors to recognize and distinguish empty and full cans on the transport carriages, the manipulating mechanism being operable in association with the sensors to transfer empty cans from the spinning positions to the empty can locations on the carriages and to transfer full sliver cans from the carriages to the spinning positions of the spinning machine.

RELATED APPLICATIONS This application is a divisional of co-pending U.S. patent application Ser. No. 13/443,180 (now U.S. Pat. No. 8,760,286), filed Apr. 10, 2012 by at least one common inventor, which is a continuation of U.S. patent application Ser. No. 12/322,941 (now U.S. Pat. No. 8,154,401), filed Feb. 9, 2009 by at least one common inventor, which claims the benefit of U.S. Provisional Patent Application No. 61/065,116 filed Feb. 8, 2008 by at least one common inventor, all of which are incorporated herein by reference in their respective entireties. BACKGROUND 1. Technical Field This invention relates generally to a system and method for monitoring location, and more specifically to a system and method for enabling communication with a tracking device. 2. Background Art Currently, systems exist for tracking the location of persons and/or property. Generally, such systems include a tracking device that transmits the location of the tracking device to a central station, which may then take some action based on the location data. Known systems have generally been very limited with respect to the communication capabilities between the tracking device and the central station. For example, communications from a tracking device to a central station have typically been limited to the transmission of a device identifier in combination with location data and, in some cases, a distress signal. Perhaps, the limited communication between tracking devices and central stations has evolved due to the disadvantages of prior art tracking systems. For example, in personal tracking devices power consumption is a serious concern, because the devices power storage capacity is a limiting factor with respect to the amount of communication that can take place. Another concern is the cost of network access (e.g., mobile phone air time). What is needed is a system and method for providing enhanced communication with tracking devices. What is also needed is a system and method for providing enhanced communication with tracking devices, while minimizing power consumption. What is also needed is a system and method for providing enhanced communication with tracking devices, while minimizing network air time. SUMMARY A system and method for providing communication with a tracking device is disclosed. The inventor has discovered that several advantages are provided by the communication system and methods disclosed herein. These advantages include the efficient use of network access time and the conservation of tracking device power. Additional advantages include enhanced efficiency and flexibility in the communication of location data from tracking devices. Yet another advantage is that functional access (e.g., setting and/or resetting of functions, parameters, etc.) to the tracking device is provided to the central station. These and other advantages will be apparent to those skilled in the art in view of the following disclosure. In a disclosed example, a tracking device includes a location detector, a communication device, memory, a processor, and a configuration routine. The location detector (e.g., a Global Positioning Satellite receiver) is operative to determine locations of the tracking device. The communication device (e.g., a cell phone modem) is operative to communicate with a remote system (e.g., a central station, subscriber server, etc.). The memory stores data and code, the data including location data determined by the location detector and configuration data. The processor is operative to execute the code to impart functionality to the tracking device. The functionality of the tracking device depends at least in part on the configuration data. The configuration routine is operative to modify the configuration data responsive to a communication from the remote system. Thus, functional access to the tracking device is provided to the remote system. The tracking device can be configured and reconfigured in many ways. In one example, the configuration data modifiable responsive to the communication from the remote system at least partially determines an interval for communicating the location data to the remote system. In another example, the configuration data modifiable responsive to the communication from the remote system at least partially determines an interval for buffering the location data when the communication device is unable to communicate the location data to the remote system (e.g., out of communication range). The interval for buffering the location data can be, for example and without limitation, a time interval (e.g., every 30 minutes) or a distance interval (e.g., whenever the tracking device moves 50 yards). In yet another example, the configuration data modifiable responsive to the communication from the remote system at least partially determines a power state of the location detector. In yet another example, the configuration data modifiable responsive to the communication from the remote system at least partially determines a monitored condition with respect to the location of the tracking device (e.g., a “geofence”). For example and without limitation, the monitored condition can be a geographical area (e.g., circular or polygonal, etc.), a velocity, a distance, a time/distance relationship (e.g., a time the tracking device remains stationary), or any combination of these. In yet another example, the configuration data modifiable responsive to the communication from the remote system at least partially determines a threshold distance between one of the locations and subsequent ones of the locations for storing the subsequent ones of the locations (e.g., only buffer location data if the tracking device has moved at least the threshold distance). As even yet another example, the configuration data modifiable responsive to the communication from the remote system at least partially determines an interval for communicating diagnostic information from the tracking device to the remote system. The example tracking device also includes a data transfer routine operative to communicate operational data between the tracking device and the remote system. In one example, the tracking device includes a battery and the data transfer routine responsive to a request from the server is operative to communicate data indicative of the status of the battery to the remote system. In another example, the data transfer routine responsive to a request from the server is operative to communicate data indicative of a radio signal strength to the remote system. In yet another example, the data transfer routine responsive to a request from the server is operative to communicate data indicative of a status of the location detector to the remote system. In yet another example, the data transfer routine responsive to a status of a monitored location condition (e.g., a geofence definition) is operative to communicate data indicative of a violation or satisfaction of the location condition to the remote system. As yet another example, the data transfer routine responsive to a request from the server is operative to communicate diagnostic data to the remote system. Another feature of the example tracking device is that when the communication device is unable to establish a connection with the remote system, the location data is accumulated in the memory. Then, when the communication device is able to establish a connection with the remote server, the data transfer routine communicates the accumulated data to the remote system. An example method for communicating with a tracking device is also disclosed. The method includes communicating with the tracking device via a wireless network and providing configuration data to the tracking device via the wireless network. The configuration data causes the tracking device to operate according to a first configuration. The method further includes receiving processed data from the tracking device. The processed data is generated by the tracking device in the first configuration. The method further includes providing new configuration data to the tracking device via the wireless network. The new configuration data changes the first configuration of the tracking device to a different configuration. The method further includes receiving additional processed data from the tracking device. The additional processed data is generated by the tracking device in the different configuration. In the example method, the configuration data at least partially determines a location data reporting interval. In another example method, the configuration data at least partially determines a location data buffering interval. In yet another example method, the configuration data at least partially determines a power state of the tracking device. In yet another example method, the configuration data at least partially determines a location based condition that if violated or satisfied causes an indication of the violation or satisfaction of the location based condition to be communicated from the tracking device to the remote system. In yet another example method, the configuration data at least partially determines a diagnostic reporting interval. In yet another example method, the configuration data at least partially determines a distance threshold for buffering location data. In yet another example method, the processed data includes data indicative of a battery status of the tracking device. In yet another example method, the processed data includes data indicative of a radio signal strength determined by the tracking device. In yet another example method, the processed data includes data generated by a diagnostic routine of the tracking device. Many other detailed examples are disclosed in the communication protocol specification set forth below. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is described with reference to the following drawings, wherein like reference numbers denote substantially similar elements: FIG. 1 is a block diagram of a tracking system; FIG. 2 is a block diagram of a server of the tracking system of FIG. 1 ; FIG. 3 is a block diagram of a subscriber system of the tracking system of FIG. 1 ; FIG. 4 is a block diagram of a tracking device of the tracking system of FIG. 1 ; and FIG. 5 is a flow chart summarizing an example method of communicating with the tracking device of FIG. 1 and FIG. 4 . DETAILED DESCRIPTION FIG. 1 is a block diagram of a system 100 for tracking and/or monitoring one or more tracking devices 102 ( 1 - m ). System 100 includes one or more servers 104 ( 1 - m ), a subscriber profile database 106 , a vendor information database 108 , a public database cache 110 , and tracking interface 112 , all intercommunicating via an internal network 114 . System 100 communicates with remote components including one or more vendors 116 ( 1 - n ), one or more subscribers 118 ( 1 - p ), and one or more public databases 120 ( 1 - q ), all via an internetwork 122 (e.g., the Internet). A firewall 124 provides a measure of security for internal network 114 against threats via internetwork 122 . Servers 104 host services for subscribers 118 and/or other authorized users that facilitate the tracking and/or monitoring of the location of tracking devices 102 . Subscriber profile database 106 stores information associated with particular subscribers 118 and/or other users of system 100 . Vendor information database 108 stores information associated with vendors 116 that provide goods and or services that can be made available to subscribers 118 and/or other users of system 100 based on information from subscriber profile database 106 and/or location data received from tracking devices 102 . Public database cache 110 provides temporary storage for data retrieved from public databases 120 . Tracking interface 112 transmits (via wireless communication) data and commands to tracking devices 102 and receives data (e.g., location data, sensor readings, distress signal, etc.) from tracking devices 102 . Vendors 116 offer goods and services that may be offered to subscribers and other users of system 100 as described above. In addition, information associated with vendors (e.g., type of business) can be used to help define boundaries used to monitor tracking devices 102 . Similarly, public databases 120 provide information (e.g., sex offender registries, etc.) that can be used as criteria for defining boundaries. Subscribers 118 are the primary users of system 100 and interact with servers 104 to define tracking criteria and to obtain information and alerts regarding the tracking of associated tracking devices 102 . In this example, the primary users are referred to as subscribers, because it is expected that users will be willing to pay for the right to use system 100 . However, it should be understood that system 100 is not limited to a subscription type business model. For example, access to system 100 could be provided to users on a free basis, relying on some other business model to raise revenue. In addition communication between tracking devices 102 and servers 104 , the communication methods described herein can be used to provide direct communication between tracking devices 102 and subscribers 118 via a communication link (e.g., mobile phone network), which is not shown in FIG. 1 . Similarly, the communication methods described herein can be used to provide direct communication between tracking devices 102 (e.g., GPS enabled cell phone to GPS enabled cell phone). In that case tracking devices 102 can function as both a tracking device and a subscriber system. FIG. 2 is a block diagram of a server 102 of tracking system 100 . Server 102 includes non-volatile data storage 202 , one or more processing units 204 , memory 206 , user I/O devices 208 , and a network interface 210 . Nonvolatile data storage 202 stores data and code that is retained even when server 104 is powered down. Memory 206 stores data and code that when processed by processing unit(s) 204 imparts functionality to server 104 . User input/output devices 208 (e.g., keyboard, mouse, monitor, etc.) provide a means of interaction between server 104 and a local human user. Network interface 210 provides a communication link to other components on internal network 114 and internetwork 122 . For the sake of clear explanation data and code are shown in memory 206 as functional blocks. It should be understood, however, that the various functions of server 104 need not be run in any particular location of memory 206 and may grouped in any useful manner. For example, the several application program interfaces (APIs) shown could be grouped into a single API. Memory 206 includes an operating system 214 , public database API 216 , subscriber API 218 , processing queues 220 , vendor API 222 , control and coordination routines 224 , application programs 226 , and a tracking device communication protocol 228 . Operating system 214 provides low level control of server 104 and provides a platform on top of which the other modules can operate. Application programs 226 are tracking service programs that receive and process location and/or sensor data from tracking devices 102 , process the received data, communicate with subscribers 118 , read and/or update subscriber profile database 106 , search remote data sources, and so on. Public database API 216 , vendor API 222 , and subscriber API 218 provide a means of communication between application programs 226 and public databases 120 , vendors 116 , and subscribers 118 , respectively. Control and coordination module 224 provides overall control and coordination of the tracking services provided by server 104 . Processing queues 220 provide temporary storage for tracking data that is being processed. Tracking device communication protocol 228 defines a protocol for communicating with tracking device 102 . In this particular embodiment, this communication occurs via network 114 , tracking interface 112 , and the wireless connection with tracking devices 102 . It is sometimes, therefore, referred to as the over-the-air protocol. The definitions and functionality of an example tracking device communication protocol 228 is fully described below. FIG. 3 is a block diagram of a subscriber system 118 of tracking system 100 . Subscriber system 118 includes non-volatile data storage 302 , one or more processing units 304 , memory 306 , user I/O devices 308 , and a network interface 310 , all intercommunicating via a bus 312 . Memory 306 includes operating system 314 , application programs 316 , subscriber API 318 , and tracking device communication protocol 320 . Application programs 316 provide various tracking based services (e.g., set up tracking account, associate particular tracking devices 102 with user account, receive and/or display real time and/or historical location information associated with particular tracking devices 102 , and so on). Subscriber API 318 (in conjunction with subscriber API 218 of server 104 shown in FIG. 2 ) facilitates communication between application programs 316 of subscriber system 118 and application programs 226 of server 104 ( FIG. 2 ). Tracking device communication protocol 320 is similar to tracking device communication protocol 228 of server 104 , except that tracking device communication protocol 320 resides on a subscriber system 118 . Therefore, tracking device communication protocol 320 facilitates direct communication between subscriber system 118 and tracking device 102 via a separate communication link (not shown), such as a mobile telephone network. FIG. 4 is a block diagram of a tracking device 102 of tracking system 100 . Tracking device server 102 includes non-volatile data storage 402 , one or more processing unit(s) 404 , memory 406 , location detector (e.g., GPS receiver) 408 with optional sensors (e.g., temperature sensor, motion sensor, etc.), and a wireless communication device 410 , all intercommunicating via a bus 412 . Memory 406 includes an operating system 414 , application programs 416 , a tracking API 418 , location data 420 , tracking device communication protocol 422 , and sensor data 424 . Application programs 416 facilitate the processing of location data 420 and/or sensor data 424 , provide alerts and/or updates to server 104 ( FIG. 1 ), facilitate updates to existing routines or the addition of new routines, and provide any other specified functionality for tracking device 102 . For example, application programs 416 can be updated or replaced by server 104 via tracking interface 112 . Tracking API facilitates communication between application programs 416 and application programs 226 of server 104 , for example, to communicate location data from tracking device 102 to server 104 . Sensor data 424 and location data 420 can be accessed by application programs 416 as needed. Data indicative of the velocity of tracking device 102 can be characterized as either sensor data or location data. Tracking device communication protocol 422 is similar to tracking device communication protocol 228 , except that tracking device protocol 422 operates on the device side of the communication link. The following is a detailed description of a particular example of a tracking device communication protocol. 1. Gradient Fields 1.1 Overview Many of the fields within the structures in this document use index values to pass a value measured by or stored at the device. When a data field is defined as a gradient, the firmware will calculate an index value as the number of increments from a defined base value. This value, an integer, will be placed within the structure for transmission. index=(measurement−base)/increment When the server receives the index value, that actual measured value is calculated by first retrieving the pre-defined values for base, increment, and unit of measure from a table lookup. These values are stored based on Device Type and Firmware Version, and are applied uniformly for all devices sharing these characteristics. Once the server has retrieved the conversion values, the actual measurement value is calculated as measurement=base+(index*increment) The server will can then store the calculated result as a high-precision value in the database. System presentation layers can convert these values to the localized measurement system for display, using the unit of measure field as a helper. 1.2 Field List with Suggested Metrics The following table lists the structure fields defined as gradient fields. All gradient fields are defined as integer values. The suggested base and increment are suggested values only. The developer must decide the actual base and increment to meet the requirements for range and granularity imposed by the specific implementation. Field Type Incre- Unit of Range Definition Data Type Base ment Measure (Rounded) RSSI Byte −113 2 dBm −113 to 397 dBm BATTERY Unsigned 0 1 mV 0 to 65.5 volts Short ALTITUDE Unsigned −4000 1 Decimeter −400 to 6,153 Short meters/−1312 to 20,188 feet SPEED Unsigned 0 1 Dekameters 0 to 6,553 Short meters per hour/0 to 407 miles per hour BEARING Unsigned 0 1 1/100 ths of a 360 degrees Short degree DISTANCE Unsigned 0 1 Hectometers 0 to 6,553 Short kilometers/0 to 4,072 miles DOP Byte 0 0.2 Absolute 0 to 50.8 VDOP Byte 0 0.2 Absolute 0 to 50.8 HDOP Byte 0 0.2 Absolute 0 to 50.8 GPSSNR Byte 0 1 dB 0 to 255 dB 2. Data Types The following data types are referenced in this document. 2.1 Primitives Name Byte Length Comment Byte 1 No type checking Short Integer 2 Integer values from −32,768 to 32,767. Little endian. Unsigned Short 2 Integer values from 0 to 65,535. Little endian. Integer 4 Integer values from −2147483648 to 2147483647. Little endian. Unsigned Integer 4 Integer values from 0 to 4,294,967,296. Little endian. Float 4 A single-precision 32-bit IEEE 754 floating point value. 2.2 Defined Types Name Data Type Length Comment DATETIME Byte Array 6 YMDHMS CRC32 Integer 4 Result of CRC-32 hash LATITUDE Float 4 LONGITUDE Float 4 DATETIME Unsigned Integer 4 RSSI Byte 1 Gradient field containing the data transceiver Received Signal Strength Indication BATLEVEL Unsigned Short 2 Gradient field containing battery condition. ALTITUDE Unsigned Short 2 Gradient field containing an altitude value. SPEED Unsigned Short 2 Gradient field containing a speed or velocity value. BEARING Unsigned Short 2 Gradient field containing a compass bearing or course direction value. DISTANCE Unsigned Short 2 Gradient field containing a linear distance value. 3. Constants The following constant values are referenced in this document. 3.1 Transport Structure IDs See section 5 Structure Summary. 3.2 Device Types Name Value Comment DT_HERMES 0x01 Use for Hermes hardware specification devices. DT_PPC 0x02 Use for Windows Pocket PC devices. 3.3 GPS Fix States Name Value Comment GPS_NOFIX 0x01 GPS is powered on but could not establish a fix. GPS_SEARCHING 0x02 GPS is establishing a fix. GPS_LOCONLY 0x03 GPS fix two dimensional without altitude. GPS_LOCALT 0x04 GPS has a full three dimension fix with altitude. GPS_POWEROFF 0x05 GPS is powered off. 3.4 GPS Power States Name Value Comment GPS_POWERDOWN 0x01 Power down the GPS. GPS_POWERUP 0x02 Power up the GPS and attempt to obtain a fix. GPS_POWERDOWNUNTIL 0x03 Power down until the wake up time. 3.5 Interactivity Modes Name Value Comment IMODE_HIGN 0x01 High Interactivity mode. IMODE_LOW 0x02 Low Interactivity mode. 3.6 Geofence Types Name Value Comment GFT_INCLUSION 0x01 GFT_EXCLUSION 0x02 GFT_BOTH 0x03 GFT_POLYGON 0x04 GPT_CIRCULAR 0x05 GFT_VELOCITY 0x06 GFT_STATIONARY 0x07 GFT_MOVEMENT 0x08 3.7 NACK Types Name Value Comment NACK_UNKNOWN 0x01 NACK_NOT_SUPPORTED 0x02 NACK_FAIILED_CRC 0x03 NACK_INVALID_LENGTH 0x04 4. Structure Summary Utility structures are not included in the summary. Orientation Manifest Mobile Host to Protocol Usage Structure Name Type Value to host Mobile UDP RHTTP DHTTP TCP SMS UDP_ENVELOPE Transport n.a. ✓ ✓ ✓ RHTTP_ENVELOPE Transport n.a. ✓ ✓ ✓ DHTTP_ENVELOPE Transport n.a. ✓ ✓ ✓ TCP_ENVELOPE Transport n.a. ✓ ✓ ✓ SMS_ENVELOPE Transport n.a. ✓ ✓ ✓ GET_DEVICE_ID Request 0x0101 ✓ ✓ ✓ ✓ ✓ ✓ GET_CURRENT_LOCATION Request 0x0102 ✓ ✓ ✓ ✓ ✓ ✓ GET_BATTERY_STATUS Request 0x0103 ✓ ✓ ✓ ✓ ✓ ✓ GET_RSSI Request 0x0104 ✓ ✓ ✓ ✓ ✓ ✓ GET_GPS_STATUS Request 0x0105 ✓ ✓ ✓ ✓ ✓ ✓ GET_GEOFENCE_HANDLE Request 0x0106 ✓ ✓ ✓ ✓ ✓ ✓ GET_GEOFENCES Request 0x0107 ✓ ✓ ✓ ✓ ✓ ✓ ✓ GET_CUSTOM_PARAM Request 0x0108 ✓ ✓ ✓ ✓ ✓ ✓ GET_DIAGNOSTIC Request 0x0109 ✓ ✓ ✓ ✓ ✓ ✓ GET_SYSTEMTIME Request 0x010A ✓ ✓ ✓ ✓ ✓ ✓ SET_REPORTING_INTERVAL Request 0x0201 ✓ ✓ ✓ ✓ ✓ ✓ SET_GPS_POWERSTATE Request 0x0202 ✓ ✓ ✓ ✓ ✓ ✓ SET_BUFFERING_INTERVAL Request 0x0203 ✓ ✓ ✓ ✓ ✓ ✓ SET_START_BUFFER Request 0x0204 ✓ ✓ ✓ ✓ ✓ ✓ SET_END_BUFFER Request 0x0205 ✓ ✓ ✓ ✓ ✓ ✓ SET_HEARTBEAT_PARAMETERS Request 0x0206 ✓ ✓ SET_INTERACTIVITY_MODE Request 0x0207 ✓ ✓ ✓ SET_CIRCULAR_GEOFENCE Request 0x0208 ✓ ✓ ✓ ✓ ✓ ✓ SET_POLYGON_GEOFENCE Request 0x0209 ✓ ✓ ✓ ✓ ✓ ✓ SET_VELOCITY_GEOFENCE Request 0x020A ✓ ✓ ✓ ✓ ✓ ✓ SET_STATIONARY_GEOFENCE Request 0x020B ✓ ✓ ✓ ✓ ✓ ✓ SET_DELETE_GEOFENCE Request 0x020C ✓ ✓ ✓ ✓ ✓ ✓ SET_CUSTOM_PARAM Request 0x020D ✓ ✓ ✓ ✓ ✓ ✓ SET_REPORTING_GRANULARITY Request 0x020E ✓ ✓ ✓ ✓ ✓ ✓ SET_MOVEMENT_GEOFENCE Request 0x020F ✓ ✓ ✓ ✓ ✓ ✓ SET_DIAGNOSTIC_INTERVAL Request 0x0210 ✓ ✓ ✓ ✓ ✓ ✓ SET_DEBUG_LEVEL Request 0x0211 ✓ ✓ ✓ ✓ ✓ ✓ PUT_CURRENT_LOCATION Response 0x0301 ✓ ✓ ✓ ✓ ✓ ✓ PUT_BATTERY_STATUS Response 0x0302 ✓ ✓ ✓ ✓ ✓ ✓ PUT_RSSI Response 0x0303 ✓ ✓ ✓ ✓ ✓ ✓ PUT_GPS_STATUS Response 0x0304 ✓ ✓ ✓ ✓ ✓ ✓ PUT_GEOFENCE_HANDLE Response 0x0305 ✓ ✓ ✓ ✓ ✓ ✓ PUT_GEOFENCE Response 0x0306 ✓ ✓ ✓ ✓ ✓ ✓ PUT_CUSTOM_PARAM Response 0x0307 ✓ ✓ ✓ ✓ ✓ ✓ PUT_LOCATION Response 0x0308 ✓ ✓ ✓ ✓ ✓ ✓ PUT_GEOFENCE_VIOLATION Response 0x0309 ✓ ✓ ✓ ✓ ✓ ✓ PUT_DEVICE_ID Response 0x030A ✓ ✓ ✓ ✓ ✓ ✓ PUT_LOCATION_ARRAY Response 0x030B ✓ ✓ ✓ ✓ ✓ ✓ PUT_DIAGNOSTIC Response 0x030C ✓ ✓ ✓ ✓ ✓ ✓ PUT_SYSTEMTIME Response 0x030D ✓ ✓ ✓ ✓ ✓ ✓ PUT_DEBUG_MESSAGE Response 0x030E ✓ ✓ ✓ ✓ ✓ ✓ ACK_MOBILE Acknow. 0x0401 ✓ ✓ ✓ ✓ ✓ ✓ ACK_HOST Acknow. 0x0402 ✓ ✓ ✓ ✓ ✓ ✓ NACK_MOBILE Acknow. 0x0403 ✓ ✓ ✓ ✓ ✓ ✓ NACK_HOST Acknow. 0x0404 ✓ ✓ ✓ ✓ ✓ ✓ 5. Utility Structures 5.1 Structure POSITION POSITION defines a geographic position. Member Name Data Type Bytes Comments Latitude LATITUDE 4 Longitude LONGITUDE 4 TOTAL 8 5.2 Structure CORNER CORNER defines a corner of a polygon geofence. Member Name Data Type Bytes Comments Sequence Number Byte 1 The number of the corner in clockwise sequence. Position POSITION 8 The geographic position of the corner. TOTAL 9 5.3 Structure LOCATE LOCATE defines complete information about the device location in a moment in time. Member Name Data Type Bytes Comments Position POSITION 8 Geographic position of the device. Fix Time DATETIME 6 Byte array [YMDHMS] Fix Type Byte 1 GPS Fix Type Speed SPEED 2 Speed gradient value Bearing BEARING 2 Bearing gradient value Linear Motion DISTANCE 2 Linear distance gradient value Altitude ALTITUDE 2 Altitude gradient value TOTAL 22 6. Transport Envelope Structures Transport Envelopes contain transport-specific information necessary to ensure reliable deliver of information between host and mobile applications. Each transport has a specific transport envelope that all request and response transaction structures are encapsulated within. 6.1 Structure UDP_ENVELOPE The UDP Transport Envelope is use to encase all UDP transport request and response structures. Member Name Data Type Bytes Comments Checksum CRC32 4 Checksum of the request/response structure using the CRC- 32 algorithm. SeqNo Byte 1 Sequence Number. Increment with each NEW transmission. No carry. Use same SeqNo for retransmissions. Payload Size Unsigned Short 2 SizeOf(Payload) Payload Array of Byte N Contains the request or response structure being transported. TOTAL N + 8 6.2 Structure RHTTP_ENVELOPE The Reverse HTTP Transport Envelope is use to encase all Reverse HTTP transport request and response structures. 6.2.1 Structure RHTTP_ENVELOPE Member Name Data Type Bytes Comments Timeout Unsigned Short 2 The number of seconds the client will maintain the open HTTP request waiting for a response from the host. Checksum CRC32 4 Checksum of the request/response structure using the CRC- 32 algorithm. Payload Size Unsigned Short 2 SizeOf(Payload) Payload Array of Byte N Contains the request or response structure being transported. TOTAL N + 8 6.3 Structure DHTTP_ENVELOPE The Direct HTTP Transport Envelope is use to encase all Direct HTTP transport request and response structures. Member Name Data Type Bytes Comments Checksum CRC32 4 Checksum of the request/response structure using the CRC- 32 algorithm. Payload Size Unsigned Short 2 SizeOf(Payload) Payload Array of Byte N Contains the request or response structure being transported. TOTAL N + 6 6.4 Structure TCP_ENVELOPE The TCP Transport Envelope is use to encase all TCP transport request and response structures. Member Name Data Type Bytes Comments Checksum CRC32 4 Checksum of the request/response structure using the CRC- 32 algorithm. Payload Size Unsigned Short 2 SizeOf(Payload) Payload Array of byte N Contains the request or response structure being transported. TOTAL N + 6 6.5 Structure SMS_ENVELOPE The SMS Transport Envelope is use to encase all SMS transport request and response structures. Member Name Data Type Bytes Comments Checksum CRC32 4 Checksum of the request/response structure using the CRC- 32 algorithm. Payload Size Unsigned Short 2 SizeOf(Payload) Payload Array of Byte N Contains the request or response structure being transported. TOTAL N + 8 7. GET Request Structures GET request structures can be used to initiate both host-to-mobile and mobile-to-host application-layer transactions. These requests contain a request for data, which is typically acknowledged by a corresponding PUT response structure containing the requested data. 7.1 Structure GET_DEVICE_ID GET_DEVICE_ID is used by the device during first time initialization to obtain a unique device identifier from the GTX host platform. This unique device identifier is the primary method by which the device data is organized within the GTX platform. Most subsequent requests require a valid device identified as a structure member. 7.1.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.1.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.1.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device SN Array[1 . . . 15] of byte 15 Contains a string representation of device IMEI (GSM) or MEID (CDMA). If the IMEI or ESN can not be obtained from the device, it is acceptable to submit the telephone number. This field is padded with nulls. (0x00). Firmware Float 4 Contains the firmware Version revision of the device expressed as a major version integer minor version fraction. Device Type Byte 1 Contains the device type constant. TOTAL 22 7.1.4 Expected Response A properly formatted GET_DEVICE_ID request structure will be responded to from the host with a PUT_DEVICE_ID response structure. 7.2 Structure GET_CURRENT_LOCATION GET_CURRENT_LOCATION is used by the host to request the most recent location coordinates from the mobile. 7.2.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.2.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.2.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 7.2.4 Expected Response A properly formatted GET_CURRENT_LOCATION request structure will be responded to from the mobile with a PUT_CURRENT_LOCATION response structure. 7.3 Structure GET_BATTERY_STATUS GET_BATTERY_STATUS is used by the host to request the current battery condition from the mobile. 7.3.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.3.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.3.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 7.3.4 Expected Response A properly formatted GET_BATTERY_STATUS request structure will be responded to from the mobile with a PUT_BATTERY_STATUS response structure. 7.4 Structure GET_RSSI GET_RSSI is used by the host to request the current radio signal strength condition from the mobile. The mobile actually replies with and index value from 0 to 255 that hashes the actual measured signal quality. The host calculates the actual signal quality value by referencing in a table containing domain parameters for this device type. The server stores the BASE value, the INCREMENT, an override value for transmitting the signal quality is UNKNOWN, and UNIT of measure field used for formatting the value for display. If the server received value is equal to UNKNOWN, an undefined or unknown signal quality is calculated, otherwise the server calculates the signal quality value for by multiplying the received index by INCREMENT and adding the product to BASE. 7.4.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.4.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.4.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 7.4.4 Expected Response A properly formatted GET_RSSI request structure will be responded to from the mobile with a PUT_RSSI response structure. 7.5 Structure GET_GPS_STATUS GET_GPS_STATUS is used by the host to request the current condition of the GPS receiver from the mobile. 7.5.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.5.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.5.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 7.5.4 Expected Response A properly formatted GET_GPS_STATUS request structure will be responded to from the mobile with a PUT_GPS_STATUS response structure. 7.6 Structure GET_GEOFENCE_HANDLE GET_GEOFENCE_HANDLE is used by the host to request the handle for the next available geofence parameters storage area. 7.6.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.6.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.6.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Type Byte 1 Geofence type TOTAL 3 7.6.4 Expected Response The device must respond with a PUT_GEOFENCE_HANDLE transaction containing the handle to the available storage location, or a NACK if storage is full or the geofence type is unsupported. 7.7 Structure GET_GEOFENCES GET_GEOFENCES is used by the host to request an iteration of the geofence parameter data currently stored on the device. 7.7.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.7.2 Request Orientation Mobile-to-host Host-to-mobile ✓ ✓ 7.7.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 7.7.4 Expected Response The device must respond iteratively with one PUT_GEOFENCE message for each set of geofence data currently stored. The device should NACK if not geofences are stored. 7.8 Structure GET_CUSTOM_PARAM GET_CUSTOM_PARAM is used to query a custom parameter value, such as a carrier-specific connection parameter. The parameter name to query is specified in a variable length field. Up to 255 characters may be sent using this structure, however the response will be formatted as a string in NAME=VALUE format up to 255 bytes in length. 7.8.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.8.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.8.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 BufferLen Byte 1 SizeOf(Buffer) Buffer Array[1..BufferLen] of N NAME part of Byte NAME=VALUE parameter format. TOTAL N + 3 7.8.4 Expected Response A properly formatted GET_CUSTOM_PARAM should be acknowledged with a PUT_CUSTOM_PARAM structure containing the response in NAME=VALUE format. 7.9 Structure GET_DIAGNOSTIC GET_DIAGNOSTIC is used to make a one-time request for a complete diagnostic payload. Use SET_DIAGNOSTIC_INTERVAL to establish periodic reporting of the diagnostics by the device. 7.9.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.9.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.9.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 7.9.4 Expected Response A properly formatted GET_DIAGNOSTIC should be acknowledged with a PUT_DIAGNOSTIC structure. 7.10 Structure GET_SYSTEMTIME GET_SYSTEMTIME is used to request the current UTC date and time at the host. 7.10.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 7.10.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 7.10.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 7.10.4 Expected Response A properly formatted GET_SYSTEMTIME should be acknowledged with a PUT_SYSTEMTIME structure. 8. SET Request Structures SET request structures are used to initiate both host-to-mobile and mobile-to-host application-layer transactions. These structures contain a command to alter the system running state or modify an internal parameters or values. SET requests are typically confirmed with a generic acknowledgement. 8.1 Structure SET_REPORTING_INTERVAL SET_REPORTING_INTERVAL is used by the host to set the autonomous location report interval. When the reporting interval is set to a non-zero value, the mobile report automatically transmits asynchronous PUT_LOCATION structures according to the set interval. 8.1.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.1.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.1.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Min Interval Unsigned Short 2 Minimum reporting interval in seconds. Set to Zero to turn off autonomous reporting. Reports will be sent NOT MORE often then this, regardless of the distance trigger. Max Interval Unsigned Short 2 Maximum reporting interval in seconds. Set to Zero to turn off autonomous reporting. Reports will be sent AT LEAST this often, if the distance trigger is not met. Linear Distance DISTANCE 2 Distance reporting Trigger trigger gradient. Reports will be sent when this accumulated distance is traveled. TOTAL 8 8.1.4 Expected Response A properly formatted SET_REPORTING_INTERVAL should be acknowledged with a ACK_MOBILE structure with the Acknowledgement field set to SET_REPORTING_INTERVAL. 8.2 Structure SET_GPS_POWERSTATE SET_GPS_POWERSTATE is used by the host to set the power state of the GPS receiver. 8.2.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.2.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.2.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned 2 Short New Power Byte 1 One of the GPS Power State State Constants. Wakeup DATETIME 6 If the power state is being set to GPS_POWERDOWNUNTIL, this field specifies that date and time to power back up. TOTAL 9 8.2.4 Expected Response A properly formatted SET_GPS_POWERSTATE should be acknowledged with a ACK_MOBILE structure with the Acknowledgement field set to SET_GPS_POWERSTATE. 8.3 Structure SET_BUFFERING_INTERVAL SET_BUFFERING_INTERVAL is used by the host to set the local location buffering interval. The buffering interval controls how frequently location records will be stored in the device memory in the event of a temporary out-of-coverage condition. The buffer is implemented as a circular queue. When the allocated storage for the buffer is used, new entries overwrite the oldest entry in the buffer. 8.3.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.3.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.3.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Min Interval Unsigned Short 2 Minimum reporting interval in seconds. Set to Zero to turn off autonomous reporting. Locates will be buffered NOT MORE often then this, regardless of the distance trigger. Max Interval Unsigned Short 2 Maximum reporting interval in seconds. Set to Zero to turn off autonomous reporting. Locates will be buffered AT LEAST this often, if the distance trigger is not met. Linear Distance DISTANCE 2 Distance reporting Trigger trigger gradient. Locates will be buffered when this accumulated distance is traveled. TOTAL 8 8.3.4 Expected Response A properly formatted SET_BUFFERING_INTERVAL should be acknowledged with an ACK_MOBILE structure with the Acknowledgement field set to SET_BUFFERING_INTERVAL. 8.4 Structure SET_START_BUFFER SET_START_BUFFER starts a dump of the current location buffer from the mobile to the host. When the mobile receives a request to start sending buffered data, it will begin traversing the circular queue starting with the oldest record, sending each record to the host using a PUT_LOCATION structure. Reporting stops when a SET_END_BUFFER request is received, or when the newest buffered data has been transmitted. 8.4.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.4.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.4.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 3 8.4.4 Expected Response A properly formatted SET_START_BUFFER structure should be acknowledged with a PUT_LOCATION structure containing the oldest record in the buffer. 8.5 Structure SET_END_BUFFER SET_END_BUFFER stops a dump of the location buffer from the mobile. 8.5.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.5.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.5.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 TOTAL 2 8.5.4 Expected Response A properly formatted SET_END_BUFFER should be acknowledged with a ACK_MOBILE structure with the Acknowledgement field set to SET_END_BUFFER. 8.6 Structure SET_HEARTBEAT_PARAMETERS SET_HEARTBEAT_PARAMETERS is used to set the starting parameters for the HTTP session timeout for the Reverse HTTP Transport. 8.6.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ 8.6.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.6.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Starting Interval Unsigned Short 2 Starting interval in seconds. Step Interval Unsigned Short 2 The amount to add or subtract from the timeout after a successful session or a timeout. Interval Limit Unsigned Short 2 The longest timeout interval the system will seek to, in seconds. TOTAL 8 8.6.4 Expected Response A properly formatted SET_HEARTBEAT_INTERVAL should be acknowledged with an ACK_MOBILE structure with the Acknowledgement field set to SET_HEARTBEAT_INTERVAL. 8.7 Structure SET_INTERACTIVITY_MODE SET_INTERACTIVITY_MODE is used to set the toggle between High Interactivity and Low Interactive Mode for Reverse HTTP Transport devices. When this command is sent via SMS, it still applies to the devices Reverse HTTP Transport mode. In this case, it is used as an out-of-band signal to switch to High Interactivity mode and force immediate Reverse HTTP session establishment. 8.7.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ 8.7.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.7.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Interactivity Mode Byte 1 One of the Interactivity Mode constants. Polling Rate Unsigned Short 2 For Low Interactivity mode, this sets the polling rate in seconds. TOTAL 8 8.7.4 Expected Response A properly formatted SET_INTERACTIVITY_MODE should be acknowledged with an ACK_MOBILE structure with the Acknowledgement field set to SET_INTERACTIVITY_MODE. 8.8 Structure SET_CIRCULAR_GEOFENCE SET_CIRCULAR_GEOFENCE is used to create a circular area which the device to generate alerts if the area in entered or exited. 8.8.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.8.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.8.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Handle Byte 1 Center POSITION 8 Radius DISTANCE 2 Distance gradient value Type Byte 1 GFT_INCLUSION GFT_EXCLUSION GFT_BOTH TOTAL 16 8.8.4 Expected Response ACK is the device accepts the geofence, NACK if the handle is invalid or the geofence type is unsupported. 8.9 Structure SET_POLYGON_GEOFENCE SET_CIRCULAR_GEOFENCE is used to create a rectangular area which the device will generate alerts if the area in entered or exited. 8.9.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.9.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.9.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Handle Byte 1 Corner Count Byte 1 Corners Array[1 . . . Corner N * 8 Count] of CORNER Type Byte 1 GFT_INCLUSION GFT_EXCLUSION GFT_BOTH TOTAL N * 8 + 5 8.9.4 Expected Response ACK is the device accepts the geofence, NACK if the handle is invalid or the geofence type is unsupported. 8.10 Structure SET_VELOCITY_GEOFENCE SET_CIRCULAR_GEOFENCE is used to create a threshold speed which the device will generate alerts if the threshold is exceeded. 8.10.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.10.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.10.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Handle Byte 1 Speed SPEED 2 Speed gradient value TOTAL 11 8.10.4 Expected Response ACK is the device accepts the geofence, NACK if the handle is invalid or the geofence type is unsupported. 8.11 Structure SET_STATIONARY_GEOFENCE SET_STATIONARY_GEOFENCE is used to create a threshold period of time which the device will generate alerts if it is stationary for a period of time greater than the threshold. 8.11.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.11.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.11.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Handle Byte 1 Trigger Speed SPEED 2 Speed gradient value Time at Rest DATETIME 6 TOTAL 13 8.11.4 Expected Response ACK is the device accepts the geofence, NACK if the handle is invalid or the geofence type is unsupported. 8.12 Structure SET_DELETE_GEOFENCE SET_DELETE_GEOFENCE is used to delete the parameters associated with a particular geofence and suppress alerting based on those parameters. 8.12.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.12.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.12.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Handle Byte 1 TOTAL 3 8.12.4 Expected Response ACK is the geofence could be deleted, NACK if the handle is invalid. 8.13 Structure SET_CUSTOM_PARAM SET_CUSTOM_PARAM is used to set a custom parameter, such as a carrier-specific connection parameter. The parameter is specified in a variable length field in NAME=VALUE format. Up to 255 characters may be sent using this structure. 8.13.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.13.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.13.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 BufferLen Byte 1 SizeOf(Buffer) Buffer Array[1 . . . BufferLen] of N Parameter in Byte NAME = VALUE format. TOTAL N + 3 8.13.4 Expected Response A properly formatted SET_CUSTOM_PARAM should be acknowledged with an ACK_MOBILE structure with the Acknowledgement field set to SET_CUSTOM_PARAM. 8.14 Structure SET_REPORTING_GRANULARITY SET_REPORTING_GRANULARITY is used to set the threshold distance between internal location samples. When a reporting granularity value is set, the device will not accumulate inter-sample distances below the set distance. This is designed to dampen phantom location “drift” generated by a stationary device. 8.14.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.14.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.14.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Distance DISTANCE 2 Distance gradient value TOTAL 4 8.14.4 Expected Response A properly formatted SET_REPORTING_GRANULARITY should be acknowledged with a ACK_MOBILE structure with the Acknowledgement field set to SET_REPORTING_GRANULARITY. 8.15 Structure SET_MOVEMENT_GEOFENCE SET_MOVEMENT_GEOFENCE is used to create a threshold distance which the device to generate alerts if that distance is traveled. This is different than setting reporting based on distance because when a movement geofence is set, the device will report PUT_GEOFENCE_VIOLATION when the distance has been traveled. 8.15.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.15.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.15.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Handle Byte 1 Trigger Distance DISTANCE 2 Distance gradient value TOTAL 11 8.15.4 Expected Response ACK is the device accepts the geofence, NACK if the handle is invalid or the geofence type is unsupported. 8.16 Structure SET_DIAGNOSTIC_INTERVAL SET_DIAGNOSTIC_INTERVAL is used by the host to set the request periodic diagnostic payload reporting. When the reporting interval is set to a non-zero value, the mobile automatically transmits asynchronous PUT_DIAGNOSTIC structures according to the set interval. 8.16.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.16.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.16.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Min Interval Unsigned Short 2 Minimum reporting interval in seconds. Set to Zero to turn off autonomous reporting. Reports will be sent NOT MORE often then this, regardless of the distance trigger. Max Interval Unsigned Short 2 Maximum reporting interval in seconds. Set to Zero to turn off autonomous reporting. Reports will be sent AT LEAST this often, if the distance trigger is not met. Linear Distance DISTANCE 2 Distance reporting Trigger trigger gradient. Reports will be sent when this accumulated distance is traveled. TOTAL 8 8.16.4 Expected Response A properly formatted SET_DIAGNOSTIC_INTERVAL should be acknowledged with a ACK_MOBILE structure with the Acknowledgement field set to SET_DIAGNOSTIC_INTERVAL. 8.17 Structure SET_DEBUG_LEVEL SET_DEBUG_LEVEL is used by the host to set the debug reporting level for the device. Debug level 0 turns off reporting. Other levels are firmware defined. Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 8.17.1 Request Orientation Mobile-to-host Host-to-mobile ✓ 8.17.2 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Debug Level Byte 1 TOTAL 3 8.17.3 Expected Response A properly formatted SET_DEBUG_LEVEL should be acknowledged with a ACK_MOBILE structure with the Acknowledgement field set to SET_DEBUG_LEVEL. 9. PUT Response Structures PUT Request structures are used to acknowledge host-to-mobile and mobile-to-host application-layer transactions. These structures typically contain a response to a GET request. PUT requests may also be used to asynchronously deliver event notifications. When delivering an asynchronous notification, they may be confirmed with a generic acknowledgement. 9.1 Structure PUT_CURRENT_LOCATION PUT_CURRENT_LOCATION is used to respond to and acknowledge a GET_CURRENT_LOCATION request. 9.1.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.1.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.1.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Location LOCATE 22 TOTAL 28 9.2 Structure PUT_BATTERY_STATUS PUT_BATTERY_STATUS is used to respond to and acknowledge a GET_BATTERY_STATUS request. 9.2.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.2.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.2.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Battery Level BATLEVEL 4 TOTAL 10 9.3 Structure PUT_RSSI PUT_RSSI is used to respond to and acknowledge a GET_RSSI request. The mobile actually replies with and index value from 0 to 255 that hashes the actual measured signal quality. The host calculates the actual signal quality value by referencing in a table containing domain parameters for this device type. The server stores the BASE value, the INCREMENT, an override value for transmitting the signal quality is UNKNOWN, and UNIT of measure field used for formatting the value for display. If the server receives value is equal to UNKNOWN, an undefined or unknown signal quality is calculated, otherwise the server calculates the signal quality value for by multiplying the received index by INCREMENT and adding the product to BASE. 9.3.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.3.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.3.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Radio Signal RSSI 1 Strength TOTAL 7 9.4 Structure PUT_GPS_STATUS PUT_GPS_STATUS is used to respond to and acknowledge a GET_GPS_STATUS request. 9.4.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.4.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.4.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Fix Type Byte 1 One of the GPS Fix State constants. Satellites Byte 1 Number of satellites in view of the receiver. DOP Byte 1 Gradient; Dilution of Precision from the GPS, if available. VDOP Byte 1 Gradient; Vertical Dilution of Precision from the GPS, if available. HDOP Byte 1 Gradient; Horizontal Dilution of Precision from the GPS, if available. Accuracy Byte 1 Accuracy in meters. 255 is used for anything greater than 254. TOTAL 11 9.5 Structure PUT_GEOFENCE_HANDLE The device responds to a GET_GEOFENCE_HANDLE message with PUT_GEOFENCE_HANDLE. After retrieving the handle, the host can set a geofence using the supplied handle. 9.5.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.5.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 9.5.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Handle Byte 1 TOTAL 7 9.5.4 Expected Response The host should transmit a desired geofence message type using the supplied handle. 9.6 Structure PUT_GEOFENCE PUT_GEOFENSE is used by the device to transmit the parameters of a particular geofence. PUT_GEFENCE could used in response to a require for a specific geofence's parameters, or PUT_GEOFENCE could be transmitted iteratively for each stored geofence in response to GET_GEOFENSES. 9.6.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.6.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 9.6.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Handle Byte 1 Type Byte 1 Geofence type Radius Unsigned Integer 4 Corner Byte 1 Count Corners Array[1 . . . Corner Count] N * 9 of CORNER TOTAL N * 9 + 13 9.7 Structure PUT_CUSTOM_PARAM PUT_CUSTOM_PARAM is used to respond to a GET_CUSTOM_PARAM structure with the value of a custom parameter, such as a carrier-specific connection parameter. The response is formatted in a variable length field in NAME=VALUE format. Up to 255 characters may be sent using this structure. 9.7.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.7.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 9.7.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. DBufferLen Byte 1 SizeOf(Buffer) Buffer Array[1 . . . BufferLen] of N Parameter in Byte NAME = VALUE format. TOTAL N + 7 9.8 Structure PUT_LOCATION PUT_LOCATION is used to send an unacknowledged coordinate fix from the mobile to the host. This coordinate fix may be initiated by a request from the host to begin autonomous interval reporting, or to stream buffered location data in response to a request from the host to dump the buffer, or may be initiated by the device after a back-in-cellular-coverage condition. 9.8.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.8.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.8.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response Location LOCATE 22 TOTAL 28 9.9 Structure PUT_GEOFENCE_VIOLATION PUT_GEOFENCE_VIOLATION is used to signal that a geofence boundary has been crossed or a threshold has been exceeded. 9.9.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.9.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.9.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Handle Byte 1 Geofence Handle Location LOCATE 22 TOTAL 29 9.10 Structure PUT_DEVICE_ID PUT_DEVICE_ID is send by the host in response to a GET_DEVICE_ID request structure. 9.10.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.10.2 Request Orientation Mobile-to-host Host-to-mobile ✓ 9.10.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 TOTAL 6 9.11 Structure PUT_LOCATION_ARRAY PUT_LOCATION_ARRAY is used to send multiple coordinate fixes from the mobile to the host. This may be initiated by a request from the host to begin to stream buffered location data in response to a request from the host to dump the buffer, or may be initiated by the device after a back-in-cellular-coverage condition. PUT_LOCATION_ARRAY should be used whenever more than one buffered locate record is being set to the host. The maximum number of locates that can be passed in the array is 255, but implementation limitations such as maximum transport payload may significantly limit this number. It is the developer's responsibility to insure that a structure small enough to be supported by the transport layer is created. 9.11.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.11.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.11.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response Array Size Byte 1 Number of LOCATE elements in the array Locations Array[1 . . . Array N * 22 Size] of LOCATE TOTAL 7 + (N * 22) 9.11.4 Expected Response Because of the relatively large amount of data carried in a PUT_LOCATION_ARRAY structure, it should be acknowledged with an ACK_HOST structure with the Acknowledgement field set to PUT_LOCATION_ARRAY. 9.12 Structure PUT_DIAGNOSTIC PUT_DIAGNOSTIC is used to respond to and acknowledge a GET_DIAGNOSTIC request and to send periodic diagnostic payloads if requested by SET_DIAGNOSTIC_INTERVAL. 9.12.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.12.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.12.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Location LOCATION 20 GPSSNR Byte 1 GPS Signal to noise ratio in dB Battery Level BATLEVEL 2 Satellites Byte 1 Number of satellites in view of the receiver. Accuracy Byte 1 Accuracy in meters. 255 is used for anything greater than 254. DOP Byte 1 Gradient; Dilution of Precision from the GPS, if available. VDOP Byte 1 Gradient; Vertical Dilution of Precision from the GPS, if available. HDOP Byte 1 Gradient; Horizontal Dilution of Precision from the GPS, if available. Network Status Byte 1 TOTAL 28 9.13 Structure PUT_SYSTEMTIME PUT_SYSTEMTIME is used to respond to and acknowledge a GET_SYSTEMTIME request and to send the current UTC date and time at the host. 9.13.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.13.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.13.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 System Time DATETIME 6 UTC time at the host. TOTAL 8 9.14 Structure PUT_DEBUG_MESSAGE PUT_DEBUG_MESSAGE is used to send debugging messages from the device to the server. This is a firmware defined implementation. 9.14.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 9.14.2 Orientation Mobile-to-host Host-to-mobile ✓ 9.14.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Debug Message Binary Var Variable length field. TOTAL Var 10. Acknowledgements Acknowledgements are generic positive and negative confirmations of requests and notifications. They are also used to carry “no operation” signaling for some transport models. 10.1 Structure ACK_MOBILE ACK_MOBILE is a generic acknowledgement for requests from the host that do not have a specific response structure. ACK_MOBILE is also used as a special purpose structure to open an HTTP transmission channel from the mobile to the host. The mobile will keep the HTTP session open for the period of time defined in the Timeout value in the Reverse HTTP Transport Envelope. If the host desired to send an application-layer request to the mobile, it creates a properly formatted request structure within a Reverse HTTP Transport Envelope, BINHEX encodes the entire payload, transmits the payload through the open socket, and closes the socket. 10.1.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 10.1.2 Orientation Mobile-to-host Host-to-mobile ✓ 10.1.3 Structure Definition Member Name Data Type Byte Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response Acknowledgement Unsigned Short 2 The Structure ID of the last transmission to acknowledge. Baggage Unsigned Short 2 Additional acknowledgement information. TOTAL 10 10.2 Structure ACK_HOST ACK_HOST is a generic acknowledgement for requests from the mobile that do not have a specific response structure. ACK_HOST is also a special purpose structure used to close an HTTP transmission channel from the when the timeout period is about to expire and the host does not need to submit a command to the mobile. ACK_HOST simple tells the mobile that the data session is still active. Typically, the mobile will reestablish a new HTTP session with the host, submitting an ACK_MOBILE structure. In Reverse HTTP High Interactivity mode, this reestablishment will occur immediately, and in Reverse HTTP Low Interactivity mode, the client will wait a defined amount of time before re-polling the host for a command. 10.2.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ 10.2.2 Orientation Mobile-to-host Host-to-mobile ✓ 10.2.3 Structure Definition Member Name Data Type Byte Comments Structure ID Unsigned Short 2 Acknowledgement Unsigned Short 2 The Structure ID of the last transmission to acknowledge. Baggage Unsigned Short 2 Additional acknowledgement information. TOTAL 6 10.3 Structure NACK_MOBILE NACK_MOBILE is used to negatively acknowledge a request structure received by the mobile device. NACK should only be used if the envelope fails checksum verification or if an unsupported request is made by the host. 10.3.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 10.3.2 Orientation Mobile-to-host Host-to-mobile ✓ 10.3.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Short 2 Device ID Unsigned Integer 4 Device ID returned in the PUT_DEVICE_ID response. Do not NACK an invalid response to GET_DEVICE_ID. Resend the GET_DEVICE_ID request. Acknowledgement Unsigned Short 2 The Structure ID of the transmission to that generated the error. Baggage Unsigned Short 2 Additional acknowledgement information. Type Byte 1 NACK Type constant TOTAL 11 10.4 Structure NACK_HOST NACK_HOST is used to negatively acknowledge a request structure received by the host. NACK_HOST should only be used if the envelope fails checksum verification or if an unsupported request is made by the mobile. 10.4.1 Protocol Usage UDP Reverse HTTP Direct HTTP TCP SMS ✓ ✓ ✓ ✓ ✓ 10.4.2 Orientation Mobile-to-host Host-to-mobile ✓ 10.4.3 Structure Definition Member Name Data Type Bytes Comments Structure ID Unsigned Integer 2 Acknowledgement Unsigned Short 2 The Structure ID of the transmission to that generated the error. Baggage Unsigned Short 2 Additional acknowledgement information. Type Byte 1 NACK Type constant TOTAL 7 11. UDP Transport Use Cases UDP Transactions consist of a properly formatted request structure placed inside a properly formatted UDP transport envelope structure and sent to the GTX platform host address. 11.1 Mobile Client First-Time Initialization or Cold-Start Mobile-to-host Host-to-mobile GET_DEVICE_ID PUT_DEVICE_ID 11.2 Host Request Location Host-to-mobile Mobile-to-host GET_CURRENT_LOCATION PUT_CURRENT_LOCATION 11.3 Start or Stop Interval Location Reporting Host-to-mobile Mobile-to-host SET_REPORTING_INTERVAL ACK_MOBILE After defined non-zero interval: PUT_LOCATION 11.4 Host Request Battery Level Host-to-mobile Mobile-to-host GET_BATTERY_LEVEL PUT_BATTERY_LEVEL 11.5 Host Request Radio Status Host-to-mobile Mobile-to-host GET_RSSI PUT_RSSI 11.6 Host Request GPS Status Host-to-mobile Mobile-to-host GET_GPS_STATUS PUT_GPS_STATUS 11.7 Host Set GPS Power State Host-to-mobile Mobile-to-host SET_GPS_POWERSTATE ACK_MOBILE 11.8 Host Set Buffering Interval Host-to-mobile Mobile-to-host SET_BUFFERING_INTERVAL ACK_MOBILE 11.9 Start Buffered Data Transmission Host-to-mobile Mobile-to-host SET_START_BUFFER PUT_LOCATION Repeats until a stop buffer transmission request is received or the newest record has been transmitted: PUT_LOCATION 11.10 Stop Buffered Data Transmission Host-to-mobile Mobile-to-host END_BUFFERED_DATA ACK_MOBILE 11.11 Establish Circular Geofence Host-to-mobile Mobile-to-host GET_GEOFENCE_HANDLE PUT_GEOFENCE_HANDLE SET_CIRCULAR_GEOFENCE ACK_MOBILE 11.12 Establish Polygon Geofence Host-to-mobile Mobile-to-host GET_GEOFENCE_HANDLE PUT_GEOFENCE_HANDLE SET_POLYGON_GEOFENCE ACK_MOBILE 11.13 Establish Velocity Geofence Host-to-mobile Mobile-to-host GET_GEOFENCE_HANDLE PUT_GEOFENCE_HANDLE SET_VELOCITY_GEOFENCE ACK_MOBILE 11.14 Establish Stationary Geofence Host-to-mobile Mobile-to-host GET_GEOFENCE_HANDLE PUT_GEOFENCE_HANDLE SET_STATIONARY_GEOFENCE ACK_MOBILE 12. Reverse HTTP Transport Use Cases Reverse HTTP Application-layer transactions are coupled with the HTTP transport-layer transaction for mobile-initiated requests and decoupled from the HTTP transport-layer transaction for host-initiated requests. 12.1 Mobile Client First-Time Initialization or Cold-Start Mobile-to-host Host-to-mobile GET_DEVICE_ID PUT_DEVICE_ID 12.2 Idle State: Mobile Waiting for Command from Host Mobile-to-host Host-to-mobile ACK_MOBILE ACK_HOST In Reverse HTTP High Interactivity mode, a new HTTP session is established immediately. In Reverse HTTP Low Interactivity Mode, a defined interval elapses before the mobile re-polls the host for a command. If any mobile-initiated events occur during this period, the mobile established an HTTP session immediately and sends the host a structure. ACK_MOBILE ACK_HOST or <any valid request> 12.3 Host Request Location Mobile-to-host Host-to-mobile ACK_MOBILE GET_CURRENT_LOCATION PUT_CURRENT_LOCATION <any valid request> 12.4 Start or Stop Interval Location Reporting Mobile-to-host Host-to-mobile ACK_MOBILE SET_REPORTING_INTERVAL ACK_MOBILE <any valid request> After defined non-zero interval: PUT_LOCATION <any valid request> 12.5 Host Request Battery Level Mobile-to-host Host-to-mobile ACK_MOBILE GET_BATTERY_LEVEL PUT_BATTERY_LEVEL <any valid request> 12.6 Host Request Radio Status Mobile-to-host Host-to-mobile ACK_MOBILE GET_RSSI PUT_RSSI <any valid request> 12.7 Host Request GPS Status Mobile-to-host Host-to-mobile ACK_MOBILE GET_GPS_STATUS PUT_GPS_STATUS <any valid request> 12.8 Host Set GPS Power State Mobile-to-host Host-to-mobile ACK_MOBILE SET_GPS_POWERSTATE ACK_MOBILE <any valid request> 12.9 Host Set Buffering Interval Mobile-to-host Host-to-mobile ACK_MOBILE SET_BUFFERING_INTERVAL ACK_MOBILE <any valid request> 12.10 Start Buffered Data Transmission Mobile-to-host Host-to-mobile ACK_MOBILE GET_BUFFER PUT_LOCATION <any valid request> After defined non-zero interval: PUT_LOCATION <any valid request> 12.11 End Buffered Data Transmission Mobile-to-host Host-to-mobile ACK_MOBILE END_BUFFERED_DATA ACK_MOBILE <any valid request> 12.12 Set Heartbeat Interval Mobile-to-host Host-to-mobile ACK_MOBILE SET_HEARTBEAT_INTERVAL ACK_MOBILE <any valid request> 12.13 Set Interactivity Mode Mobile-to-host Host-to-mobile ACK_MOBILE SET_INTERACTIVITY_MODE ACK_MOBILE <any valid request> FIG. 5 is a flow chart summarizing a method 500 for communicating with a tracking device using, for example, the above-described communication protocol. In a first step 502 , communication is established between the tracking device (e.g., tracking device 102 ) and a remote system (e.g., system 104 ) via a wireless network (e.g., a mobile phone network). Then, in a second step 504 configuration data is provided to the tracking device from the remote server. Next, in a third step 506 , the remote server receives processed data from the tracking device. Then, in a fourth step 508 a determination is made whether the configuration of the tracking device should be changed. If so, then in a fifth step 510 , different configuration data is provided to the tracking device to reconfigure the tracking device. Then, in a sixth step 512 , the remote system receives additional processed data from the tracking device, which has been processed and/or provided by the tracking device in the tracking device's new configuration. If in fourth step 508 it is determined that no configuration change is necessary, then method 500 proceeds to sixth step 512 where the remote system receives addition processed data from the tracking device, but the additional processed data will have been processed and/or provided by the tracking device in the tracking device's first configuration. The description of particular example embodiments of the present invention is now complete. Many of the described features may be substituted, altered or omitted without departing from the scope of the invention. For example, the tracking devices of the present invention can be embodied in an article of clothing worn by a tracked subject. As another example, tracking devices 102 and/or subscriber systems 118 can be embodied in GPS enabled mobile telephones or other hand-held position determining devices. These and other deviations from the particular embodiments shown will be apparent to those skilled in the art, particularly in view of the foregoing disclosure.

A system and method for providing communication with a tracking device are disclosed. An example tracking device includes a location detector, a communication device, memory, a processor, and a configuration routine. The location detector is operative to determine locations of the tracking device. The communication device is operative to communicate with a remote system. The memory stores data and code, the data including location data determined by the location detector and configuration data. The processor is operative to execute the code to impart functionality to the tracking device. The functionality of the tracking device depends at least in part on the configuration data. The configuration routine is operative to modify the configuration data responsive to communications from the remote system. Thus, functional access to the tracking device is provided to the remote system.

FIELD OF THE INVENTION This invention relates generally to stabilized earthen structures, and specifically relates to an adjustable turnbuckle style assembly for connecting precast concrete panels to a previously constructed wire face wall, which has been or may be subjected to foundation settlement. BACKGROUND OF THE INVENTION Retaining wall structures may be comprised of backfill or earth material with a facing of precast panels. Mechanically stabilized earth structures are generally described in a series of Vidal patents including U.S. Pat. Nos. 3,421,326, 3,686,873, 4,045,965, and 4,116,010. Vidal disclosed that longitudinal, tensile members positioned within a granular, compacted mass of earth to thereby enhance the coherency of the particles that form the mass. The stabilized soil mass can then serve as a wall or embankment. This phenomenon of enhanced coherency is accomplished, at least in part, by frictional engagement of particles in the mass with the tensile members or tie strips extending through the mass. Often such stabilized earthen mass includes a facing made from precast concrete panels. A variety of methods and apparatus are known for attaching the tensile members projecting from the stabilized earthen mass to the precast concrete panels. For example, U.S. Pat. No. 4,961,673, issued to Pagano, discloses a connector that attaches a mounting plate, extending from the back face of a panel to a tie strip extending from within the stabilized soil mass. The attachment is achieved by threading a bolt through the opening in both the tie strip and the mounting plate and securing the bolt with a nut. The Pagano arrangement permits little adjustability with regard to horizontal and vertical offsets of the panel connectors vis-à-vis the tiestrips when installed. U.S. Pat. No. 5,971,669, issued to Crigler, discloses a connector that permits some horizontal and vertical adjustments at the attachment points of the precast concrete panels and the tensile strips of the mechanically stabilized earth structure. The Crigler connection has a two-part housing, i.e., there are two, separate female connectors that threadably receive the male turnbuckle through the open end of the housing. The connection attaches the wire mesh panels that define a face for the stabilized soil mass, to precast concrete facing panels. The attachment at the panel facing is made by means of an elongate member oriented substantially parallel to the ground level that passes through the aperture at the end of the first housing as well as apertures that extend from the face of the precast concrete panels. The apertures are lined up, and the elongate member is passed through the series of apertures to secure the connector. The connection at the precast concrete panel wall, however, allows movement in the longitudinal direction of the member between the apertures. When constructing an earth retaining wall of the type described, the granular material, which is compacted for cooperation with the tensile members, may not fully consolidate to its final volume during the period of wall construction. For example, compacted earth may only consolidate approximately 90% of its expected bulk consolidation during the construction phase of such a retaining wall. Over time, the bulk form may therefore continue to consolidate and, as a result, differential settlement may occur between the soil mass and the precast panel facing. Due not only to the difficulties inherent in predicting differential settlement, but also to general variations in construction tolerances, the connecting points between the precast concrete panels and a previously constructed wire face wall may not line up in directly opposing positions. In this event, some vertical and horizontal offset between the connecting points may necessarily result. SUMMARY OF THE INVENTION The present invention is a low-cost connector assembly that efficiently allows for significant differential settlement between precast concrete facing panels and the mechanically stabilized earth mass without transferring undue stress to the wall panels. The invention is an adjustable assembly that connects fixed points on the face of the precast concrete panels to the wire mesh wall that can accommodate significant offsets between connection points. The universal joint connections allow the connector assemblies to be rotated such that the connection points in the closest proximity can be linked. The invention provides a plurality of connectors where the ends are pivotally connected at fixed spaced pivot points to accommodate misalignment by forming angled rather than straight connections, which in combination defines a three-dimensional truss. The ends of each connector define a first array at the facing panels and a second array at the connection of the connector to the stabilized earth structure such as to a wire mesh facing. These and other objectives, advantages, and features of the invention will be set forth in the detailed description which follows. BRIEF DESCRIPTION OF THE DRAWING In the detailed description which follows, reference will be made to the drawing comprised of the following figures: FIG. 1 is an elevation view of a mechanically stabilized earth mass connected to a panel wall by multiple connection assemblies. FIG. 2 is a plan view of FIG. 1 . FIG. 3 is a perspective view of the completed connector assembly incorporating the present invention with ladder-type tensile members used in the mechanically stabilized earth mass. FIG. 4 is a perspective view of the completed alternative connector assembly incorporating the present invention with the connection at the panel face in a generally horizontal orientation. FIG. 5 is a perspective view of the completed connector assembly incorporating the present invention with strip-type tensile members in the mechanically stabilized earth mass, and a connection at the panel face in the vertical orientation. FIG. 6 is a perspective view of the completed connector assembly incorporating the present invention with the connection at the panel face in the horizontal orientation. FIG. 7 is an elevation view of the connection to the mechanically stabilized earth mass. FIG. 8 is a plan view of FIG. 7 . FIG. 9 is a plan view of the slotted clip used in the connection to the mechanically stabilized earth mass. FIG. 10 is an elevation view of the connector assembly. DETAILED DESCRIPTION OF THE INVENTION The connector assembly of the present invention can be illustrated by describing the method of installation of the connector with reference to the drawing FIGS. 1, 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , and 10 . Like numbers thus designate like parts in the respective drawings. FIGS. 1 and 2 illustrate a completed mechanically stabilized earth mass 400 . The wire facing units 200 form the face of the mechanically stabilized earth mass 400 . Tensile reinforcement 300 , 301 is connected to the wire facing units 200 and passes through the earth mass. A panel wall 125 is connected to the wire facing units 200 by a plurality of connector assemblies 150 . An array of connector assemblies 150 at various angled directions define in combination a three dimensional space truss 500 that resists wall movement horizontally, vertically, as well as inward or outward from the face of the mechanically stabilized earth mass. FIG. 3 illustrates the configuration and appearance of a connector assembly 150 in relation to a panel wall 125 and the wire facing units 200 of a mechanically stabilized earth mass 400 . The panel wall 125 is preferably comprised of multiple precast concrete forms or panels 126 . The connector assembly, also referred to as a turnbuckle assembly, 150 is comprised of a threaded rod 100 that is threadably received by coil nuts 111 A, 111 B at each end which are connected respectively to coil loops 110 A, 110 B. The coil nuts 111 A, 111 B are typically connected to the coil loops 110 A, 110 B offsite and prior to construction by welding. The connector assembly 150 is also shown in FIG. 10 . The coil loops, or longitudinal loops, 111 A, 111 B and coil nuts, or threaded sockets, 110 A, 110 B form connection adjustment mechanisms, also referred to as turnbuckle brackets, 112 A, 112 B that permit the connector assembly 150 to be lengthwise adjustable by turning the threaded rod 100 (or loops 110 A, 110 B) in a turnbuckle fashion thus simultaneously retracting or extending coil loops 110 A, 110 B from the midpoint between the loops 110 A, 110 B. The first coil loop 110 A is attached to the precast concrete panel 125 at a generally fixed connection point. The precast concrete panel 125 has a slotted clip, or linkage, 105 protruding from the back face 120 of the wall 125 . The slotted clip 105 is also referred to as a linkage. The slotted clip 105 is a curved member with the crown 105 A protruding from the back face 120 of the wall panel 125 , and the legs 127 A, 127 B extending into the wall panel 125 . The slotted clip 105 has apertures 107 A, 107 B in the legs 127 A, 127 B of the slotted clip 105 that receive an anchor rod 106 . The anchor rod 106 distributes the tensile stress exerted by the connector assembly and prevents a pull-out type failure. The anchor rod 106 is inserted into the apertures 107 A, 107 B of the slotted clip 105 and cast-in-place within the precast concrete panel 125 such that it is an integral part of the panel 125 . The crown 105 A of the slotted clip 105 has a notch 108 cut out at the midpoint to receive the coil loop 110 A of the connector assembly 150 at this connection point. The notch 108 is of sufficient size to allow the connector assembly 150 to be pivotally rotated from side to side about the longitudinal axis of a bolt 102 . As the slotted clip 105 is cast in concrete, the pivot points are generally fixed at spaced intervals. Thus, after inserting the coil loop 110 A into the notch 108 cut out of the slotted clip 105 , and aligning the aperture of the coil loop 110 A with the apertures created by the crown 105 A of the slotted clip 105 that extend beyond the back face of the panel 125 , a pin, typically a bolt, 102 is inserted vertically through the aperture 110 A and the apertures created by the crown 105 A to affix the connection. The bolt 102 is secured with a nut 104 and washers 103 A, 103 B on each end to prevent the bolt 102 from passing through the apertures created by the crown 105 A of the slotted clip 105 . When the pin 102 is secured, a univeral joint mechanism 140 is formed that allows the connector assembly 150 to pivotally move with respect to the panel wall 125 . The second coil loop 110 B is attached to the wire facing or mesh 200 of the mechanically stabilized earth mass 400 , also called the retained backfill. A second slotted clip, or linkage, 201 is connected to the wire facing 200 where a ladder-type tensile member 300 extends rearward into retained backfill. The slotted clip 201 is curved with apertures 205 A, 205 B in the legs 227 A, 227 B of slotted clip 201 . FIG. 9 shows the aperture 205 A in greater detail. The slotted clip 201 is connected to the ladder member 300 by means of a bolt connection. The end of the ladder member 300 has a connector section or plate 301 , a flat tab section with an aperture in the center. The connector section or plate 301 is typically connected to the ladder member 300 offsite and prior to construction by means of welding. The slotted clip 201 is placed over a rod member 202 A of the wire facing unit 200 such that the rod member is within the throat of the slotted clip 201 . The apertures 205 A, 205 B of the slotted clip 201 are aligned with the aperture 301 A of the connector section 301 such that a pin, typically a bolt, 212 can be passed through the apertures 205 A, 205 B, 301 A to affix clip 201 to plate 301 . The bolt 212 is secured with nut 211 and washers 210 A, 210 B positioned on the outside of the slotted clip 201 . When the pin 212 is secured, a universal joint mechanism 240 is formed that allows the connector assembly to pivotally move with respect to the wire mesh facing 200 . FIGS. 7, 8 , and 9 show the universal joint mechanism in detail. The crown 201 A of the slotted clip 201 has a notch 206 cut out at the midpoint to receive the coil loop 110 B of the connector assembly 150 . The notch 206 is of sufficient size to allow the connector assembly 150 to be pivotally rotated. After inserting the coil loop 110 B into the notch 206 cut out of the slotted clip 201 , and aligning the aperture of the coil loop 110 B with the apertures created by the crown 201 A of the slotted clip 201 , a connector rod 202 is inserted horizontally through the apertures created by the crown of the slotted clip 201 to affix the connection. The connection of the connector assembly 150 to the connection adjustment mechanisms 112 A, 112 B forms an adjustable connector construction. A slotted clip 201 and coil loop 110 B assembly is typically provided at the end of each ladder member 300 prior to construction of the precast panel wall 125 so that the threaded rod 100 of the connector assembly 150 can be rotated to locate the nearest coil loop 110 B after the connector assembly 150 has been attached to the back face 120 of the panel 125 . Either end of the connector assembly 150 can be connected first, and then rotated freely to find the nearest connection point for the opposite end of the assembly 150 . For example, the connector assembly 150 can be initially attached to the wire facing unit 200 and then freely rotated to locate the nearest slotted clip 105 embedded in a precast concrete panel 125 . Alternatively, the connector assembly 150 can be initially attached to a slotted clip 105 embedded in the concrete panel 125 and then rotated to locate the nearest coil loop 110 B for making the connection. Threading the rod 100 into the coil nut 111 B completes the connection and fixes the panel 125 from inward or outward movement. FIG. 4 illustrates the configuration and appearance of the connector assembly in relation to the panel wall 125 and the wire facing units 200 of the mechanically stabilized earth mass. The configuration and appearance of the connector assembly in FIG. 4 differs from that presented in FIG. 3 only in that the orientation of the slotted clip 105 and anchor rod 106 in the precast concrete panel are rotated such that the bolt 102 is inserted horizontally through the apertures to affix the connection. FIG. 5 illustrates the configuration and appearance of the connector assembly in relation to the panel wall 125 and the wire facing units 200 of the mechanically stabilized earth mass. The configuration and appearance of the connector assembly in FIG. 5 differs from that presented in FIG. 3 in that the slotted clip 201 is connected to a tensile strip 310 by means of the bolted connection. As mentioned previously, various forms of tensile reinforcement are disclosed in the prior art, which are typically selected based on the backfill material. Note, however, that the tensile reinforcement may simply be selected based upon the availability of construction materials. FIG. 6 illustrates the configuration and appearance of the connector assembly in relation to the panel wall 125 and the wire facing units 200 of the mechanically stabilized earth mass. The configuration and appearance of the connector assembly in FIG. 6 differs from that presented in FIG. 5 only in that the orientation of the slotted clip 105 and anchor rod 106 in the precast concrete panel are rotated such that the bolt 102 is inserted horizontally through the apertures to affix the connection. FIG. 7 illustrates the universal joint mechanism 240 at the face of the wire mesh wall 200 . Thus, having described the foregoing invention, one skilled in the art would be enabled to practice the invention and know of the best mode for such practice contemplated by the inventor herein. Also one having such skill would readily understand many variations and changes that could be made in the above system without departing from the scope and content thereof.

Mechanically stabilized retaining wall structures are comprised of a stabilized earth mass connected to a precast concrete panel facing wall. A lengthwise adjustable turnbuckle style connector assembly accommodates horizontal and vertical offsets in the connection points. An array of the connection assemblies comprise a three-dimensional space truss that accomodates wall movement horizontally and vertically with respect to the wall face as well as perpendicular to the wall.

REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. provisional application No. 61/990,583 filed May 8, 2014, and 62/029,260 filed Jul. 25, 2014, the content of each of which is incorporated herein by reference. FIELD [0002] This technology relates to treating, inhibiting, or preventing the progression of amyotrophic lateral sclerosis, primary lateral sclerosis, or familial amyotrophic lateral sclerosis, or a symptom of each thereof, conditions leading to or arising from them, and/or negative effects of each thereof by administering phenoxyalkylcarboxylic acids. BACKGROUND [0003] Amyotrophic lateral sclerosis (ALS) also referred to as Lou Gehrig's disease, is a rapidly progressive, fatal neurological disease that attacks the neurons responsible for controlling voluntary muscles. Subjects with ALS frequently die from respiratory failure, usually within 3 to 5 years from the onset of symptoms. As many as 20,000-30,000 people in the U.S. alone have ALS, and an estimated 5,000 people in the U.S. are diagnosed with the disease each year. ALS is one of the most common neuromuscular diseases worldwide, and people of all races and ethnic backgrounds are affected. ALS most commonly affects people between 40 and 60 years of age, but younger and older people also can develop the disease. Men are affected more often than women. SUMMARY [0004] In one aspect, a method is provided for treating, inhibiting, or preventing the progression of a disorder selected from amyotrophic lateral sclerosis (ALS), primary lateral sclerosis (PLS), and familial ALS, or a symptom thereof in a patient suffering therefrom, the method comprising administering to the patient an effective amount of a compound of Formula (I): [0000] [0000] or a metabolite thereof, or an ester of the compound of Formula (I) or the metabolite thereof, or a pharmaceutically acceptable salt of each thereof, wherein m is an integer from 2 to 5 inclusive, and n is an integer from 3 to 8 inclusive, X 1 and X 2 each independently represent sulfur, oxygen, a sulfinyl group or a sulfonyl group, provided that X 1 and X 2 are not simultaneously oxygen. [0005] In one embodiment, the disorder treated is ALS or a symptom thereof. In another embodiment, the disorder treated is PLS or a symptom thereof. In another embodiment, the disorder treated is familial ALS or a symptom thereof. [0006] In another embodiment, the disorder inhibited is ALS or a symptom thereof. In another embodiment, the disorder inhibited is PLS or a symptom thereof. In another embodiment, the disorder inhibited is familial ALS or a symptom thereof. [0007] In another embodiment, the disorder whose progression is prevented is ALS or a symptom thereof. In another embodiment, the disorder whose progression is prevented is PLS or a symptom thereof. In another embodiment, the disorder whose progression is prevented is familial ALS or a symptom thereof. [0008] In one embodiment, the compound of Formula (I) is a compound of Formula (IA) (or MN-001): [0000] [0009] In another embodiment, the metabolite of the compound of Formula (I) and (IA) is a compound of Formula (IB) (or MN-002): [0000] BRIEF DESCRIPTION OF THE FIGURES [0010] FIG. 1 graphically illustrates comparative life span in Sod1 mutants (Sod1 − ) and wt (Sod1+). Maximum life span of mutants is 25-30 days compared to 70-80 days for controls; recovering on life span curve can indicate positive compound activity. [0011] FIG. 2 graphically illustrates high (% viability) sensitivity of SOD1-null adults compared to a wild stock after exposition of adult flies to 2 mmol of paraquat. Resistance to paraquat treatment can indicate positive activity of the compound tested. [0012] FIG. 3 graphically illustrates that flies with interfered SOD gene (DMSO), show lower survival percentages after paraquat exposure (See SOD-DMSO and SOD-No Paraquat) and that treatment with either of the two positive control compounds (the anti-SMA compound riluzole or the antioxidant vitamin E) increased this percentage, as did. MN-001 in a dose dependent manner. [0013] FIG. 4 graphically illustrates percent viability at 29° C. of at least 150 flies of each genotype analyzed: F1 of wild-type cross, F1 of VAPB mutant cross; and VAPB mutant in stock. ***p-value<0.0001 were calculated with a t-student test using the Graph pad program. DETAILED DESCRIPTION [0014] As used herein, and in the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. [0015] “Administering” or “administration of” a drug to a patient (and grammatical equivalents of this phrase) includes both direct administration, including self-administration, and indirect administration, including the act of prescribing a drug. For example, as used herein, a physician who instructs a patient to self-administer a drug and/or provides a patient with a prescription for a drug is administering the drug to the patient. [0016] “C X ” when placed before a group refers to the number of carbon atoms in that group to be X. [0017] “Alkyl” refers to a monovalent acyclic hydrocarbyl radical having 1 to 12 carbon atoms. Non-limiting examples of alkyl include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl and the like. [0018] “Aryl” refers to a monovalent aromatic hydrocarbyl radical having up to 10 carbon atoms. Non-limiting examples of aryl include phenyl and naphthyl. [0019] “Heteroaryl” refers to an aromatic group of from 1 to 10 carbon atoms and 1 to 4 heteroatoms selected from the group consisting of oxygen, nitrogen, sulfur within the aromatic ring, wherein the nitrogen and/or sulfur atom(s) of the heteroaryl are optionally oxidized (e.g., N-oxide, —S(O)— or —S(O) 2 —). Such heteroaryl groups can have a single ring (e.g., pyridyl or furyl) or multiple condensed rings (e.g., indolizinyl or benzothienyl) wherein the condensed rings may or may not be aromatic and/or contain a heteroatom provided that the point of attachment is through an atom of the aromatic heteroaryl group. Non limiting examples of heteroaryl include pyridyl, pyrrolyl, indolyl, thiophenyl, and furyl. [0020] “Cycloalkyl” refers to a monovalent non-aromatic cyclic hydrocarbyl radical having 3-12 carbon atoms. Non-limiting examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. [0021] “Heterocyclyl” refers to a monovalent non-aromatic cyclic group of 1 to 10 carbon atoms and 1 to 4 heteroatoms selected from the group consisting of oxygen, nitrogen, sulfur within the cycle, wherein the nitrogen and/or sulfur atom(s) of the heteroaryl are optionally oxidized (e.g., N-oxide, —S(O)— or —S(O) 2 —). Such heteroaryl groups can have a single ring (e.g., piperidinyl or tetrahydrofuranyl) or multiple condensed rings wherein the condensed rings may or may not be aromatic and/or contain a heteroatom provided that the point of attachment is through an atom of the non-aromatic heterocyclyl group. Non limiting examples of heterocyclyl include pyrrolidinyl, piperidinyl, piperazinyl, and the like. [0022] “Amino” refers to —NH 2 . [0023] “Alkylamino” refers to —NHR B , wherein R B is C 1 -C 6 alkyl optionally substituted with 1-3 aryl, heteroaryl, cycloalkyl, or heterocyclyl group. [0024] “Dialkylamino” refers to —N(R B ) 2 , wherein R B is defined as above. [0025] “Comprising” shall mean that the methods and compositions include the recited elements, but not exclude others. “Consisting essentially of” when used to define methods and compositions, shall mean excluding other elements of any essential significance to the combination for the stated purpose. Thus, a composition consisting essentially of the elements as defined herein would not exclude trace contaminants from the isolation and purification method and pharmaceutically acceptable carriers, such as phosphate buffered saline, preservatives and the like. “Consisting of” shall mean excluding more than trace elements of other ingredients and substantial method steps for administering the compositions of this invention or process steps to produce a composition or achieve an intended result. Embodiments defined by each of these transitional terms and phrases are within the scope of this invention. [0026] “Effective amount” of a compound utilized herein is an amount that, when administered to a patient treated as herein, will have the intended therapeutic effect, e.g., alleviation, amelioration, palliation or elimination of one or more manifestations of the medical condition in the patient. The full therapeutic effect does not necessarily occur by administration of one dose (or dosage), and may occur only after administration of a series of doses. Thus, an effective amount may be administered in one or more administrations. [0027] “Amyotrophic lateral sclerosis (ALS)” also referred to as Lou Gehrig's disease, is a rapidly progressive, fatal neurological disease that attacks the nerve neurons responsible for controlling voluntary muscles (muscle action we are able to control, such as those in the arms, legs, and face). The disease belongs to a group of disorders known as motor neuron diseases, which are characterized by the gradual degeneration and death of motor neurons. [0028] ALS causes weakness with a wide range of disabilities. Eventually, all muscles under voluntary control are affected, and individuals lose their strength and the ability to move their arms, legs, and body. When muscles in the diaphragm and chest wall fail, people lose the ability to breathe without ventilatory support. Most people with ALS die from respiratory failure, usually within 3 to 5 years from the onset of symptoms. [0029] The earliest symptoms may include fasciculations, cramps, tight and stiff muscles (spasticity), muscle weakness affecting an arm or a leg, slurred and nasal speech, or difficulty chewing or swallowing. These general complaints then develop into more apparent weakness or atrophy. [0030] Muscle weakness and atrophy spread to other parts of the body as the disease progresses. Individuals may develop problems with moving, swallowing (dysphagia), and speaking or forming words (dysarthria). Symptoms of upper motor neuron involvement include spasticity and exaggerated reflexes (hyperreflexia) including an overactive gag reflex. An abnormal reflex commonly called Babinski's sign (the large toe extends upward as the sole of the foot is stimulated in a certain way) also indicates upper motor neuron damage. Symptoms of lower motor neuron degeneration include muscle weakness and atrophy, muscle cramps, and fasciculations. To be diagnosed with ALS, people have signs and symptoms of both upper and lower motor neuron damage that is not attributed to other causes. [0031] “Familial ALS” accounts for approximately 5 to 10 percent of all ALS cases, with the rest being sporadic (idiopathic) in origin. The presence of atypical features such as young age of onset, sensory loss, and a positive family history of ALS, other neurodegenerative disorders, and dementia indicates a possibility of familial ALS. [0032] “Primary lateral sclerosis or (PLS)” is a neuromuscular disease with slowly progressive weakness in voluntary muscle movement. PLS is a motor neuron disease. PLS affects the upper motor neurons (also called corticospinal neurons) in the arms, legs, and face. PLS often affects the legs first, followed by the body, trunk, arms and hands, and, finally the bulbar muscles (muscles that control speech, swallowing, and chewing). Symptoms include weakness, muscle stiffness and spasticity, clumsiness, slowing of movement, and problems with balance and speech. PLS is more common in men than in women, with a varied gradual onset that generally occurs between ages 40 and 60. PLS progresses gradually over a number of years, or even decades. PLS is not considered to have a hereditary cause. [0033] “Pharmaceutically acceptable” refers to non-toxic and suitable for administration to a patient, including a human patient. [0034] “Pharmaceutically acceptable salts” refer to salts that are non-toxic and are suitable for administration to patients. Non-limiting examples include alkali metal, alkaline earth metal, and various primary, secondary, and tertiary ammonium salts. When the ester of the compound of Formula (I) includes a cationic portion, for example, when the ester includes an amino acid ester, the salts thereof can include various carboxylic acid, sulfonic acid, and miner acid salts. Certain non-limiting examples of salts include sodium, potassium, and calcium salts. [0035] “Protecting groups” refer to well-known functional groups which, when bound to a functional group, render the resulting protected functional group inert to the reaction to be conducted on other portions of a compound and the corresponding reaction condition, and which can be reacted to regenerate the original functionality under de-protection conditions. The protecting group is selected to be compatible with the remainder of the molecule. A “carboxylic acid protecting group” protects the carboxylic functionality of the phenoxyalkylcarboxylic acids during their synthesis. Non limiting examples of carboxylic acid protecting groups include benzyl, p-methoxybenzyl, p-nitrobenzyl, allyl, benzhydryl, and trityl. Additional examples of carboxylic acid protecting groups are found in standard reference works such as Greene and Wuts, Protective Groups in Organic Synthesis., 2d Ed., 1991, John Wiley & Sons, and McOmie Protective Groups in Organic Chemistry, 1975, Plenum Press. Methods for protecting and de-protecting the carboxylic acids disclosed herein can be found in the art, and specifically in Greene and Wuts, supra, and the references cited therein. [0036] “Treating” a medical condition or a patient refers to taking steps to obtain beneficial or desired results, including clinical results. For purposes of the various aspects and embodiments of the present invention, beneficial or desired clinical results include, but are not limited to, reduction, alleviation, or amelioration of one or more manifestations of or negative effects of ALS, PLS or familial ALS, improvement in one or more clinical outcomes, diminishment of extent of sclerosis, delay or slowing of sclerosis progression, amelioration, palliation, or stabilization of the scleroses state, and other beneficial results described herein. [0037] Provided herein are methods administering an effective amount of a compound of Formula (I): [0000] [0000] or a metabolite thereof, or an ester of the compound of Formula (I) or the metabolite thereof, or a pharmaceutically acceptable salt of each thereof, wherein the variables are defined as herein. [0038] As used herein, “a metabolite thereof” refers to a metabolite that shows substantially similar therapeutic activity as a compound of Formula (I). Non-limiting examples of such metabolites include compounds where the —COCH 3 group, of a compound of Formula (I), that is attached to the phenyl containing the —O—(CH 2 ) n CO 2 H moiety is metabolized to a 1-hydroxyethyl (—CH(OH)Me) group. [0039] Metabolites containing such a 1-hydroxyethyl group contain an asymmetric center on the 1-position of the 1-hydroxyethyl group. The corresponding enantiomers and mixtures thereof, including racemic mixtures, are included within the metabolites of the compound of Formula (I) as utilized herein. [0040] As used herein, “an ester thereof” refers to an ester of the phenolic hydroxy group and/or an ester of the carboxylic acid shown in the compound of Formula (I), and an ester of the 1-hydroxyethyl (an aliphatic hydroxy group) group of a metabolite of the compound Formula (I). An ester of the phenolic and/or the aliphatic hydroxy groups can include, without limitation, as the corresponding acid, a carboxylic acid R A —CO 2 H, wherein R A is C 1 -C 6 alkyl, aryl, heteroaryl, C 3 -C 12 cycloalkyl, or C 2 -C 8 heterocyclyl, wherein the alkyl, aryl, heteroaryl, cycloalkyl, or heterocyclyl are optionally substituted with from 1 to 4 C 1 -C 3 alkyl, aryl, CO 2 H, amino, alkylamino, or dialkylamino groups. Other acids such as mono-, di-, or tri phosphoric acids are also contemplated. An ester of the carboxylic acid can include, without limitation, as the corresponding alcohol, a compound of formula R A —OH, wherein R A is defined as above. In one embodiment, only the carboxylic acid in Formula (I) is esterified. In another embodiment, only the phenolic hydroxy group in Formula (I) is esterified. In another embodiment, R A is C 1 -C 4 alkyl. As will be apparent to the skilled artisan, such esters act as prodrugs that are hydrolyzed in vivo to release the compound of Formula (I) or a salt thereof. [0041] In another embodiment, the compound of Formula (I) is a compound of Formula (IA): [0000] [0042] In another embodiment, the metabolite of the compound of Formula (I) and (IA) is a compound of Formula (IB): [0000] [0043] The compound may be administered orally. For example, the compound may be administered as a tablet or a capsule. In another embodiment, the compound of Formula (IA) is present in polymorphic form A that is substantially free of other polymorphic forms. In another embodiment, the compound is administered as a liquid dosage form. In another embodiment, the compound is administered in an amount from about 100 to about 4,000 mg/day, divided into one, two, or three portions. [0044] The efficacy of a compound or composition utilized herein can be demonstrated by methods well-known to the skilled artisan. For example, the methods provided can be tested in animal models of amyotrophic lateral sclerosis (ALS) well known to the skilled artisan. Mouse models such as motor neuron degeneration (Mnd), progressive motor neuronopathy (pmn), wobbler, and a canine model, such as, hereditary canine spinal muscular atrophy (HCSMA) can be employed for these purposes. Drosophila fruit fly or transgenic mouse overexpressing the mutated SOD1 gene of familial ALS patients, can be used to demonstrate the usefulness of the methods provided herein. A study of selected features from various models can demonstrate further usefulness of the methods provided herein. [0045] The synthesis and certain biological activity of the compounds of Formula (I) are described in U.S. Pat. No. 4,985,585 which is incorporated herein in its entirety by reference. For example, the compound of Formula (IA) is prepared by reacting a phenol of Formula (II): [0000] [0000] wherein, R is a carboxylic acid protecting group, with a compound of Formula (III): [0000] [0000] to provide a compound of Formula (IC): [0000] [0000] Non-limiting examples of acid protecting groups, or R groups, include C 1 -C 6 alkyl, benzyl, benzhydryl, and trityl, wherein the benzyl, benzhydryl, or trityl group is optionally substituted with from 1 to 6 C 1 -C 6 alkyl, halo, and/or C 1 -C 6 alkoxy groups. The leaving group, other than the bromo group of Formula (III), may be used. Non-limiting examples of such other leaving groups include, but are not limited to, chloro and tosylate. [0046] De-protection of the protected carboxylic acid of Formula (IC) provides the compound of Formula (IA). Compounds of Formula (IC) may be useful in accordance with any of the described methods and compounds. Non-limiting examples of de-protection methods include, but are not limited to, alkaline hydrolysis and hydrogenolysis under H 2 and a catalyst such as Pd/C or Pt/C. [0047] The reactions may be carried out in an inert organic solvent. Such solvents include, but are not limited to, methylethylketone, diethylketone, or dimethylformamide. The nucleophilic displacement reaction may be conducted at a temperature below room temperature up to the reflux temperature of the solvent, in the presence of an inorganic base, such as potassium carbonate or sodium carbonate, and optionally in the presence of potassium iodide. The reactions are carried out for a period of time sufficient to provide substantial product as determined by well-known methods such as thin layer chromatography and 1 H-NMR. Other compounds utilized herein are made by following the procedures described herein and upon appropriate substitution of starting materials, and/or following methods well known to the skilled artisan. See also, U.S. Pat. No. 5,290,812 (incorporated herein in its entirety by reference). [0048] The compound of Formula (IA) is recrystallized under controlled conditions to provide an essentially pure orthorhombic polymorph, referred to as Form A crystals (e.g., 90% or more, preferably at least 95% Form A). Polymorphic Form A and processes for producing it are described in U.S. Pat. Nos. 7,060,854 and 7,064,146; which are incorporated herein in their entirety by reference. All polymorphic forms of the compound of Formula (I) are active, but polymorphic Form A is preferred. Under certain conditions, the solubility and the bioavailability of this polymorph are superior to the other polymorphs and thus Form A may offer improved solid formulations. [0049] Form A crystals can be obtained, for example, by dissolving the compound of Formula (IA) in 5 to 10 parts by weight of ethanol at 25° C. to 40° C., to give a yellow to orange solution. The ethanol solution is charged with 1 to 10 parts of water and agitated at 20° C. to 25° C. for about 15 to 60 minutes and then at 5° C. to 10° C. for an additional period of from 1 to 4 hours, preferably 2.0 to 3.0 hours, resulting in an off-white suspension. To this suspension is added 5 to 15 parts of water and the mixture is agitated at 5° C. to 10° C. for an additional from 1 to 4 hours, preferably 1.5 to 2.0 hours. A solid, white to off-white product is isolated by vacuum filtration and the filter cake is washed with water and dried in a vacuum at 25° C. to 40° C. for 12 to 24 hours. [0050] For compounds utilized herein that exist in enantiomeric forms, such as certain metabolites of the compound of Formula (I) (for example, the compound of formula IB), the two enantiomers can be optically resolved. Such a resolution may be performed, for example, and without limitation, by forming diastereomeric salt of a base such as (S)-(−)-1-(1-naphthyl) ethylamine with the corresponding carboxylic acid compound, or by separating the enantiomers using chiral column chromatography. Intermediates to such compounds, which intermediates also exist in enantiomeric forms can be similarly resolved. [0051] Any of the compounds may be administered orally; or intravenously, intramuscularly, or subcutaneously by injection; or transdermally. Effective dosage levels can vary widely from about 100 to about 4000 mg per day. In one embodiment, the daily dosage range is 250 to 2,000 mg, given in one, two, or three portions. In one embodiment, the daily dosage range is 100 to 500 mg, such as 100, 200, 300, 400, or 500 mg given in one, two, or three portions. In one embodiment, the daily dosage range is 250 to 2,000 mg, such as 250, 500, 750, 1,000, 1,250, 1,500, 1,750, or 2,000 mg given in one, two, or three portions. In one embodiment, the daily dosage range is 1,000 to 4,000 mg, such as 1,000, 2,000, 3,000, or 4,000 mg, given in one, two, or three portions. In another embodiment, the dosage is 1000 mg twice a day. In other embodiments, suitable dosages include 1,000 mg qd, 1,000 mg bid, and 750 mg tid. [0052] Actual amounts will depend on the circumstances of the patient being treated. As those skilled in the art recognize, many factors that modify the action of the active substance will be taken into account by the treating physician such as the age, body weight, sex, diet and condition of the patient, the time of administration, the rate and route of administration. Optimal dosages for a given set of conditions can be ascertained by those skilled in the art using conventional dosage determination tests. [0053] The compounds utilized herein can be formulated in any pharmaceutically acceptable form, including liquids, powders, creams, emulsions, pills, troches, suppositories, suspensions, solutions, and the like. Therapeutic compositions containing the compounds utilized herein will ordinarily be formulated with one or more pharmaceutically acceptable ingredients in accordance with known and established practice. In general, tablets are formed utilizing a carrier such as modified starch, alone or in combination with carboxymethyl cellulose (Avicel), for example at about 10% by weight. The formulations are compressed at from 1,000 to 3,000 pounds pressure in the tablet forming process. The tablets preferably exhibit an average hardness of about 1.5 to 8.0 kp/cm 2 , preferably 5.0 to 7.5 kp/cm 2 . Disintegration time varies from about 30 seconds to about 15 or 20 minutes. [0054] Formulations for oral use can be provided as hard gelatin capsules wherein the therapeutically active compounds utilized herein are mixed with an inert solid diluent such as calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules in which the compounds are mixed with an oleaginous medium, e.g., liquid paraffin or olive oil. Suitable carriers include magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethyl cellulose, a low melting wax, cocoa butter, and the like. [0055] The compounds utilized herein can be formulated as aqueous suspensions in admixture with pharmaceutically acceptable excipients such as suspending agents including, but not limited to, sodium carboxymethyl cellulose, methylcellulose, hydroxypropylmethyl cellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents such as naturally occurring phosphatide, e.g., lecithin, or condensation products of an alkaline oxide with fatty acids, e.g., polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, e.g, heptadecaethylene-oxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol, e.g., polyoxyethylene sorbitol monoleate or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, e.g., polyoxyethylene sorbitan monoleate. Such aqueous suspensions can also contain one or more preservatives, e.g., ethyl- or n-propyl-p-hydroxy benzoate, one or more coloring agents, one or more flavoring agents and one or more sweetening agents, such as glycerol, sorbitol, sucrose, saccharin or sodium or calcium cyclamate. [0056] Suitable formulations also include sustained release dosage forms, such as those described in U.S. Pat. Nos. 4,788,055; 4,816,264; 4,828,836; 4,834,965; 4,834,985; 4,996,047; 5,071,646; and, 5,133,974, the contents of which are incorporated herein in their entirety by reference. [0057] Other forms suitable for oral administration include liquid form preparations including emulsions, syrups, elixirs, aqueous solutions, or solid form preparations which are intended to be converted shortly before use to liquid form preparations. Emulsions may be prepared in solutions, for example, in aqueous propylene glycol solutions or may contain emulsifying agents, for example, such as lecithin, sorbitan monooleate, or acacia. Aqueous solutions can be prepared by dissolving the active component in water and adding suitable colorants, flavors, stabilizing, and thickening agents. Solid form preparations may contain, in addition to the active component, colorants, flavors, stabilizers, buffers, artificial and natural sweeteners, dispersants, thickeners, solubilizing agents, and the like. [0058] The compounds utilized herein may be formulated for parenteral administration (e.g., by injection, for example bolus injection or continuous infusion) and may be presented in unit dose form in ampoules, pre-filled syringes, small volume infusion or in multi-dose containers with an added preservative. The compositions may take such forms as suspensions, solutions, or emulsions in oily or aqueous vehicles, for example as solutions in aqueous polyethylene glycol. Examples of oily or nonaqueous carriers, diluents, solvents or vehicles include propylene glycol, polyethylene glycol, vegetable oils (e.g., olive oil), and injectable organic esters (e.g., ethyl oleate), and may contain formulatory agents such as preserving, wetting, emulsifying or suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form, obtained by aseptic isolation of sterile solid or by lyophilisation from solution for constitution before use with a suitable vehicle, e.g., sterile, pyrogen-free water. [0059] The compounds utilized herein may be formulated for nasal administration. The solutions or suspensions are applied directly to the nasal cavity by conventional means, for example, with a dropper, pipette or spray. The formulations may be provided in a single or multidose form. The patient can administer an appropriate, predetermined volume of the solution or suspension via a dropper or pipette. A spray may be administered for example by means of a metering atomizing spray pump. [0060] The compounds utilized herein may be formulated for aerosol administration, particularly to the respiratory tract and including intranasal administration. The compound will generally have a small particle size for example of the order of 5 microns or less. Such a particle size may be obtained by means known in the art, for example by micronization. The active ingredient is provided in a pressurized pack with a suitable propellant such as a chlorofluorocarbon (CFC), (for example, dichlorodifluoromethane, trichlorofluoromethane, or dichlorotetrafluoroethane), carbon dioxide or other suitable gases. The aerosol may conveniently also contain a surfactant such as lecithin. The dose of drug may be controlled by a metered valve. Alternatively the active ingredients may be provided in a form of a dry powder, for example a powder mix of the compound in a suitable powder base such as lactose, starch, starch derivatives such as hydroxypropylmethyl cellulose and polyvinylpyrrolidine. The powder carrier will form a gel in the nasal cavity. The powder composition may be presented in unit dose form for example in capsules or cartridges of, for example gelatin or blister packs from which the powder may be administered by means of an inhaler. [0061] The compounds utilized herein may be formulated for topical administration to the epidermis as ointments, creams or lotions, or as a transdermal patch. Ointments and creams may, for example, be formulated with an aqueous or oily base with the addition of suitable thickening and/or gelling agents. Lotions may be formulated with an aqueous or oily base and will in general also containing one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents, thickening agents, or coloring agents. Formulations suitable for topical administration in the mouth include lozenges including active agents in a flavored base, usually sucrose and acacia or tragacanth; pastilles including the active ingredient in an inert base such as gelatin and glycerin or sucrose and acacia; and mouthwashes including the active ingredient in a suitable liquid carrier. [0062] The compounds utilized herein may be formulated for administration as suppositories. In such a formulation, a low melting wax, such as a mixture of fatty acid glycerides or cocoa butter is first melted and the active component is dispersed homogeneously, for example, by stirring. The molten homogeneous mixture is then poured into convenient sized molds, allowed to cool, and to solidify. [0063] The compounds utilized herein may be formulated for vaginal administration. Pessaries, tampons, creams, gels, pastes, foams or sprays containing in addition to the active ingredient such carriers as are known in the art to be appropriate. [0064] When desired, formulations can be prepared with enteric coatings adapted for sustained or controlled release administration of the active ingredient. A common type of controlled release formulation that may be used for the purposes of the present invention comprises an inert core, such as a sugar sphere, a first layer, coated with an inner drug-containing second layer, and an outer membrane or third layer controlling drug release from the inner layer. [0065] The cores are preferably of a water-soluble or swellable material, and may be any such material that is conventionally used as cores or any other pharmaceutically acceptable water-soluble or water-swellable material made into beads or pellets. The cores may be spheres of materials such as sucrose/starch (Sugar Spheres NF), sucrose crystals, or extruded and dried spheres typically comprised of excipients such as microcrystalline cellulose and lactose. [0066] The substantially water-insoluble material in the first layer is generally a “GI insoluble” or “GI partially insoluble” film forming polymer (dispersed or dissolved in a solvent). As examples may be mentioned ethyl cellulose, cellulose acetate, cellulose acetate butyrate, polymethacrylates such as ethyl acrylate/methyl methacrylate copolymer (Eudragit NE-30-D) and ammonio methacrylate copolymer types A and B (Eudragit RL3OD and RS30D), and silicone elastomers. Usually, a plasticizer is used together with the polymer. Exemplary plasticizers include: dibutylsebacate, propylene glycol, triethylcitrate, tributylcitrate, castor oil, acetylated monoglycerides, acetyl triethylcitrate, acetyl butylcitrate, diethyl phthalate, dibutyl phthalate, triacetin, fractionated coconut oil (medium-chain triglycerides). [0067] The second layer containing the active ingredient may be comprised of the active ingredient (drug) with or without a polymer as a binder. The binder, when used, is usually hydrophilic but may be water-soluble or water-insoluble. Exemplary polymers to be used in the second layer containing the active drug are hydrophilic polymers such as polyvinylpyrrolidone, polyalkylene glycol such as polyethylene glycol, gelatine, polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives, such as hydroxypropylmethyl cellulose (HPMC), hydroxypropyl cellulose, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxyethyl cellulose, carboxymethyl hydroxyethyl cellulose, acrylic acid polymers, polymethacrylates, or any other pharmaceutically acceptable polymer. The ratio of drug to hydrophilic polymer in the second layer is usually in the range of from 1:100 to 100:1 (w/w). [0068] Suitable polymers for use in the third layer, or membrane, for controlling the drug release may be selected from water insoluble polymers or polymers with pH-dependent solubility, such as, for example, ethyl cellulose, hydroxypropylmethyl cellulose phthalate, cellulose acetate phthalate, cellulose acetate trimellitate, polymethacrylates, or mixtures thereof, optionally combined with plasticizers, such as those mentioned above. [0069] Optionally, the controlled release layer comprises, in addition to the polymers above, another substance(s) with different solubility characteristics, to adjust the permeability, and thereby the release rate, of the controlled release layer. Exemplary polymers that may be used as a modifier together with, for example, ethyl cellulose include: HPMC, hydroxyethyl cellulose, hydroxypropyl cellulose, methylcellulose, carboxymethylcellulose, polyethylene glycol, polyvinylpyrrolidone (PVP), polyvinyl alcohol, polymers with pH-dependent solubility, such as cellulose acetate phthalate or ammonio methacrylate copolymer and methacrylic acid copolymer, or mixtures thereof. Additives such as sucrose, lactose and pharmaceutical grade surfactants may also be included in the controlled release layer, if desired. [0070] Also provided herein are unit dosage forms of the formulations. In such forms, the formulation is subdivided into unit dosages containing appropriate quantities of the active component (e.g., and without limitation, a compound of Formula (I) or an ester thereof, or a salt of each thereof). The unit dosage form can be a packaged preparation, the package containing discrete quantities of preparation, such as packeted tablets, capsules, and powders in vials or ampoules. Also, the unit dosage form can be a capsule, tablet, cachet, or lozenge itself, or it can be the appropriate number of any of these in packaged form. [0071] Other suitable pharmaceutical carriers and their formulations are described in Remington: The Science and Practice of Pharmacy 1995, edited by E. W. Martin, Mack Publishing Company, 19th edition, Easton, Pa. [0072] The present invention, thus generally described, will be understood more readily by reference to the following examples, which are provided by way of illustration and are not intended to be limiting of the present invention. EXAMPLES Example 1 Drosophila Life Span Assay as an ALS Treatment Model [0073] Drosophila males will be collected. Flies will be transferred to fresh food (with compound) every 2-3 days. The number of living flies is analyzed daily. The experiment is performed under temperature controlled conditions (25° C.) and uses negative controls (only solvent), and positive controls (wt stock, any antioxidant compound reported as able to increase life span in this fly model). In order to compare the activity of the testing compound with riluzole (an FDA-approved drug for ALS), this drug will be added to the assay. [0074] The experiment includes the analysis of four compound concentrations (10, 100, 250 and 1000 μM) and will evaluate 240 flies for each concentration (16 replicates with 15 flies each one). Recovering on life span curve can indicate positive compound activity. See FIG. 1 . [0000] Compound requirement: 10-15 mg of MN-001/MN-002 will be tested. Timing: 5 months (1-2 months to expand the fly stock and 3 months for assay execution and results interpretation). Example 2 Drosophila Paraquat Sensitivity Assay as an ALS Treatment Model [0075] Drosophila males will be collected and keep on fly food for 24 h. Then flies will be transferred to vials containing 3-mm paper filter disks saturated with 250 μl of 1% sucrose containing 2 mM paraquat or 1% sucrose, 2 mM paraquat and the tested compound. The vials will be stored at 25° C. in the dark, and flies are enumerated after 24 h. [0076] Three replicas for each concentration will be performed in the same day and three replicas of the assay will be performed in different days. A negative control (only solvent), and positive controls (wt stock, any antioxidant compound reported as able to increase life span in this fly model), and riluzole will be added to the assay. [0077] The experiment includes the analysis of four compound concentrations (10, 100, 250 and 1000 μM) and will evaluate 360 flies for each concentration (8 replicates×3 days with 15 flies each one). Resistance to paraquat treatment will be indicative of positive activity of the compound tested. See, FIG. 2 . [0000] Compound requirement: 1-3 mg of MN-001/MN-002 will be tested. Timing: 10 weeks (1-2 months to expand the fly stock, two weeks for assay execution and results interpretation) Results: [0078] MN-001 was tested at concentrations of 0.08 mM, 0.8 mM, 8 mM (DMSO). As tested, MN-001 reduced paraquat toxicity on SOD deficient flies in a dose dependent manner (see FIG. 3 ). Flies with interfered SOD gene (DMSO), show lower survival (or survivorship) percentages after paraquat exposure (See SOD-DMSO and SOD-No Paraquat). Treatment with either the two positive compounds (the anti-SMA compound riluzole or the antioxidant vitamin E) increased this percentage. MN-001 also increased this survival in a dose dependent manner. Example 3 Evaluation of Anti-ALS Activity on VAP-33a Drosophila Mutants [0079] From other mutant stocks available and involving other ALS linked genes, loss of function of Vap-33-1 gene (excision of transcribed sequence and loss of protein function) displays valid fly phenotypes for evaluation of compounds activity. Indistinctly, Vap-33A Δ448 or Vap-33A Δ20 stocks display neurophysiology defects linked to a lethal phenotype during larvae development. Viability Assay [0080] Vap-33A Δ mutants are larval lethal with rare adult escapers (˜1%). Embryos or larvae at stage 1 will be seeded on fly food with different compound concentrations (10, 25, 100 μM). Three replicas for each concentration will be performed in the same day. Three replicas of the assay will be performed in different days. Number of adult escapers will be quantified after 14 days of compound treatment. A negative control (only solvent), and positive controls (wt stock, any antioxidant compound reported as able to increase life span in this fly model), and riluzole will be added to the assay. [0081] The experiment includes the analysis of four compound concentrations (10, 100, 250 and 1000 μM) and will evaluate 180 flies for each concentration (4 replicates×3 days with 15 flies each one). [0000] Compound requirement: 5-10 mg of MN-001/MN-002 will be tested. Timing: 3 months (2 months to expand the fly stock, 1 month for assay execution and results interpretation Example 4 Evaluation of Anti-ALS Activity on VAPB Drosophila Mutants [0082] A fly-based ALS model based on VAPB gene was employed. These mutant flies displayed a reduced viability as a significant phenotype, as graphically illustrated in FIG. 3 . FIG. 3 shows the percent viability at 29° C. of at least 150 flies of each genotype analyzed: F1 of wild-type cross, F1 of VAPB mutant cross; and VAPB mutant in stock. At least five tubes seeded with fifteen L1 larvae each were analyzed each day. Data was collected during two independent days. ***p-value<0.0001 calculated with a t-student test using the Graph pad program. [0083] MN-001 was tested in the model along with DMSO, riluzole, and vitamin D. Three replicates were tested for riluzole and vitamin D (45 larvae seeded), and eight for compound B and DMSO (120 larvae seeded). [0084] The following results were obtained under the test conditions. No adult flies were observed from DMSO and riluzole. From vitamin D, 1 adult was observed in one of the 3 replicates. For MN-001, 5 of 8 wells displayed adults but only 1 adult in each of them, thereby demonstrating MN-001's ability to increase viability in a statistically significant manner. [0085] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects as defined in the following claims. [0086] The embodiments, illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising,” “including,” “containing,” etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase “consisting essentially of” will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase “consisting of” excludes any element not specified. [0087] The present disclosure is not to be limited in terms of the particular embodiments described in this application. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and compositions within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds compositions or biological systems, which can of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. [0088] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. [0089] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. [0090] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure. [0091] Other embodiments are set forth in the following claims.

A compound of Formula (I), or a metabolite thereof, or an ester of the compound of Formula (I) or the metabolite thereof, or a pharmaceutically acceptable salt of each thereof wherein: m is an integer from 2 to 5 inclusive; and n is an integer from 3 to 8 inclusive; and X 1 and X 2 are each independently sulfur, oxygen, a sulfinyl group or a sulfonyl group, provided that X 1 and X 2 are not simultaneously oxygen. Such a compound may be useful for treating, inhibiting, or preventing the progression of amyotrophic lateral sclerosis, primary lateral sclerosis, or familial amyotrophic lateral sclerosis, or a symptom of each thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a national stage application claiming priority under 35 U.S.C. § 371 to PCT Application Serial No. PCT/IE2006/000023, published as WO 2006/106492, with an international filing date of Apr. 3, 2006, the contents of which application is hereby incorporated by reference herein in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to novel assays for the determination and quantification of the phosphorylation of TRAM (Trif-related adaptor molecule). The assays may, in particular, be used to monitor the activation of Toll Like Receptor 4 (TLR4), with such a assays having utility in the identification of modulators of the activity thereof. A further aspect of the invention provides an assay for use in determining molecules which block, inhibit or competitively inhibit the phosphorylation of TRAM by protein kinase C epsilon. BACKGROUND TO THE INVENTION [0003] The Toll-like receptor (TLR) superfamily plays a central role in the recognition of invading pathogens and the initiation of an immune response. Ten human TLRs have been identified to date. Each recognises a distinct pathogen-associated molecular pattern (PAMP) leading to the activation of a signalling cascade, which in turn activates the transcription factor NF-κB and also the mitogen-activated protein kinases (MAPKs), p38, c-jun, N terminal kinase (JNK) and p42/44 (reviewed in ref 1 and 2). TLR3 and TLR4 also activate another pathway culminating in the activation of the transcription factor, IFN-regulated factor-3 (IRF3), which binds to the interferon-sensitive response element (ISRE), inducing a subset of genes including IFN-β (3). The TLRs are members of a larger superfamily, called the interleukin-1 receptor (IL-1R)/TLR superfamily, that also contains the IL-1R1 subgroup and the TIR domain-containing adaptor subgroup. All three subgroups possess a cytoplasmic Toll/IL-1 receptor (TIR) domain, which is essential for signalling. The TLRs possess extracellular leucine rich repeats, while the IL-1R1 subgroup have extracellular immunoglobin domains. The adaptor molecules are cytoplasmic and contain no extracellular region. [0004] As mentioned above, each TLR recognises a different PAMP. The first TLR to be discovered was TLR4 and it is essential for the recognition of gram-negative bacterial lipopolysaccharide (LPS) (4, 5). TLR2 coupled with TLRs 1 and 6 recognises diacyl- and triacyl-lipopetides respectively (6). TLR3 recognises dsRNA (7), TLR5 recognises bacterial flagellin (8) while TLR9 recognises unmethylated CpG motifs (9). Once a TLR has recognised a PAMP it must recruit a TIR domain-containing adaptor to activate the subsequent signalling pathway. The first of these adaptors to be identified was MyD88. It plays a key role in TLR and IL-1R signalling (10, 11, 12) and the resulting signalling cascade has been extensively studied (reviewed in 13). Evidence suggests that it is involved in signalling from all TLRs with the exception of TLR3. MyD88-deficient mice failed to respond to IL-1 stimulation, or stimulation of TLR2, TLR5 and TLR9 (11). In the case of TLR4, activation of NF-κB and MAPK still occurred albeit in a delayed manner. In addition, the induction of dendritic cell maturation and the activation of the transcription factor IRF3 were unaffected in MyD88-deficient mice. This suggested that TLR4 requires more than just MyD88 to fully activate its response and that this response could be divided into two categories, the MyD88-dependent response and the MyD88-independent response. NF-κB and TNF production were not impaired in response to TLR3 suggesting that MyD88 is not involved in TLR3 signalling. [0005] The next adaptor to be identified was Mal (MyD88 adaptor-like), which has also been called TIRAP (TIR domain-containing adaptor protein) (14, 15). It was originally thought that this could be the adaptor that mediated the MyD88-independent response to TLR4 but Mal-deficient mice proved that this was not the case and that Mal and MyD88 work together to activate the MyD88-dependent pathway. Like MyD88-deficient mice, Mal-deficient mice showed a delayed activation of NF-κB and MAPK in response to LPS while the activation of dendritic cell maturation and the transcription factor IRF3 were unaffected (15, 16). Mal-deficient mice respond normally to ligands for TLR5, TLR7, TLR9, IL-1 and IL-18 confirming the belief that MyD88 is the only adaptor required by these receptors. TLR3 signalling is also normal in Mal-deficient mice suggesting that neither Mal nor MyD88 are involved in this pathway. Interestingly, the signalling pathway activated by TLR2 was completely abolished in Mal-deficient mice suggesting that Mal and MyD88 are both required for the activation of this pathway (16). [0006] Trif (TIR domain-containing adaptor inducing interferon-β) was the third adaptor to be discovered (17, 18). It was also called TIR-containing adaptor molecule-1 (TICAM-1). Trif, when over-expressed, activated NF-κB albeit to a much lesser extent than Mal or MyD88 but it was a much stronger activator of IFN-β (17). This suggested that it may be involved in the MyD88-independent pathway and Trif-deficient mice proved this (19). NF-κB activation in response to LPS was almost normal in these mice but when these cells were deficient of Trif and MyD88, the NF-κB response to LPS was totally abolished. In Trif-deficient mice the activation of IRF3 in response to LPS was totally abolished again suggesting that Trif is involved in the MyD88-independent pathway activated by TLR4. The activation of IRF3 by TLR3 was also abolished in Trif-deficient cells and the activation of NF-κB was severely impaired suggesting that Trif is the sole adaptor used by TLR3. [0007] It was discovered that Trif could not bind directly to TLR4 (18) suggesting that a bridging adaptor is needed to bind it to TLR4. That bridging adaptor has now been discovered by several groups and is called TRAM (Trif-related adaptor molecule) (20) or TICAM-2 (TIR-containing adaptor molecule-2) (21) or TIRP (TIR domain-containing protein) (22). [0008] TRAM binds directly to TLR4 but not to the other TLRs (21). Overexpression of TRAM led to a mild induction of IRF3, IRF7 and NF-κB, independent of MyD88. A dominant negative form of TRAM inhibited activation of NF-κB and IRF3 by LPS, but had no effect on the activation of either of these transcription factors by the TLR3 ligand, Poly(I:C). Overexpression of TRAM, along with Trif, lead to the translocation of IRF3 to the nucleus (20). A dominant negative form of Trif largely suppressed the ability of TRAM to activate NF-κB and IFN-β while MyD88 and Mal dominant negative mutants had no effect. [0009] TRAM cannot function in Trif-knockdown RAW cells, suggesting that TRAM is working upstream of Trif on the TLR4 pathway. The generation of TRAM-deficient mice (23) added weight to this theory. These mice showed that TRAM was essential for activation of the MyD88-independent pathway in response to TLR4 and that it was not involved in other TLR pathways. [0010] The inventors have now surprisingly found that the adapter molecule TRAM is rapidly phosphorylated by protein kinase C epsilon following the binding of LPS to the TLR4 receptor (Toll Like Receptor 4). It is defined that TRAM is phosphorylated by protein kinase C epsilon at the site of the serine 16 residue. Assays directed to monitoring the phosphorylation of TRAM may be a useful tool in determining the activation of TLR4 and in particular whether LPS signalling through the TLR4 receptor is functioning properly in different environments. SUMMARY OF THE INVENTION [0011] According to a first aspect of the present invention there is provided a method for determining the activation status of TRAM (Trif-related adaptor molecule), said method comprising the steps of: providing a cellular sample comprising TRAM, and monitoring TRAM for phosphorylation, wherein the absence of phosphorylation of TRAM indicates that TRAM is not active. [0014] As herein defined, the term ‘activation status’ means whether TRAM is involved in a cellular signalling pathway. Accordingly, activated TRAM, results from phosphorylation of TRAM at the serine 16 residue, with TRAM, in an active form, contributing to signalling mediated through the TLR4 receptor. [0015] In a preferred embodiment of the assay, TRAM is contacted with a kinase under conditions permissive of phosphorylation. In one embodiment the kinase may be protein kinase C epsilon. [0016] In a further embodiment of the assay, TRAM phosphorylation is monitored with regard to a control in order to determine phosphorylation. [0017] In a further embodiment, TRAM phosphorylation is measured with regard to the presence of TRAM within the membrane of a cell. Phosphorylation of TRAM causes movement of TRAM out of the cell membrane. [0018] Accordingly a further embodiment of this aspect of the invention provides for determining the phosphorylated state of TRAM by determining the presence or level of TRAM present in the cell membrane, wherein the absence or a decrease of the presence of TRAM within the membrane is indicative of TRAM being in a phosphorylated state wherein it moves out of the membrane. [0019] Accordingly in one embodiment the method used to determine the phosphorylation of TRAM comprises a membrane depletion assay which determines and/or quantifies the presence and/or level of TRAM within a cell membrane. [0020] Without being bound by theory, the inventors predict that the movement of TRAM out of the cell membrane following phosphorylation is caused by phosphorylation of the TRAM at the serine 16 residue causing a negative charge to be imparted which causes a repulsive force which results in movement of TRAM out of the membrane. [0021] As herein described, the molecule referred to as TRAM (Trif-related adaptor molecule) may also be referred to as TICAM-2 (TIR-containing adaptor molecule-2) (21) or TIRP (TIR domain-containing protein) (22). [0022] The above assays for determining the state of phosphorylation of TRAM can be further modified to allow the identification of candidate agents which can modulate TRAM activation. [0023] Accordingly a further embodiment of this aspect of the invention provides a method for identification of modulator(s) of TRAM activity, said method comprising the steps of: (i) providing first and second cellular samples containing TRAM, (ii) contacting said first sample with a candidate modulator of TRAM, (iii) contacting said first and second samples with a kinase under conditions permissive of phosphorylation, and (iv) monitoring the phosphorylation status of TRAM, and comparing the phosphorylation of TRAM between said first and second samples, wherein a difference in TRAM phosphorylation between said first and second samples identifies the candidate modulator as a modulator of TRAM activity. [0028] In one embodiment, the kinase which phosphorylates TRAM is protein kinase C epsilon. [0029] The modulator(s) identified according to the above assays of this aspect of the present invention may be a peptide or non-peptide molecule such as a chemical entity or pharmaceutical substance. Where the modulator is a peptide it may be an antibody, an antibody fragment, or a similar molecule with binding activity. Further, where the modulator is an antibody, preferably it is a monoclonal antibody. [0030] A further aspect of the present invention provides for the use of a modulator identified according to the previous aspect of the invention in the preparation of a medicament of modulating the signalling mediated through the TLR4 receptor. In one embodiment signalling through the TLR4 receptor is upregulated. In a further, preferred embodiment, signalling mediated through the TLR4 receptor is downregulated. [0031] A yet further aspect of the invention provides a kit for the determination of the phosphorylation of TRAM, the kit comprising a reference sample, means for determining the phosphorylation of TRAM and instructions for the performance of any of the assays of the invention using the methods of the first aspect of the invention. [0032] In as much as the above aspects of the invention describes assay methods for assessing the phosphorylated state of TRAM and the identification of compositions useful for modulating the same, the present invention has further utility in the provision of an assay for assessing the activation of the TLR4 receptor by a ligand and in particular by LPS. Such an assay may be of significant value in the identification and development of compounds which may selectively up-regulate or down-regulate signalling through the TLR4 receptor. Such compounds would have significant utility as modulators of the signalling pathway which results from TLR4 binding and most specifically TLR4 binding by LPS (lipopolysaccharide). [0033] According to a fourth aspect of the present invention there is provided an assay method for the detection of TLR4 activation by a ligand, the assay comprising the steps of: providing a cellular sample comprising cells expressing TLR4, bringing said cells into contact with the ligand, and detecting the phosphorylation of TRAM, wherein phosphorylation of TRAM is indicative of the binding of a ligand to TLR4. [0037] Preferably the level of phosphorylation can be compared to a control sample, such as the same type of cells which are not exposed to the ligand. Alternatively, the test sample can be controlled to a known, pre-determined reference value. [0038] By determining phosphorylation it is possible to identify candidate agents which modify the phosphorylation of TRAM through their interaction with the TLR4 receptor. [0039] A further aspect of the present invention provides for the use of a ligand identified according to the previous aspect of the invention in the preparation of a medicament of modulating the signalling mediated through the TLR4 receptor. In one embodiment signalling through the TLR4 receptor is upregulated. [0040] Accordingly a further embodiment of the fourth aspect of the present invention provides an assay for identifying an agonist of the TLR4 receptor, said assay comprising the steps of: providing a cellular sample including cells which express TLR4, exposing the cells to a test compound, detecting the phosphorylation of TRAM, wherein an increase in the phosphorylation of TRAM is indicative of activation of the TLR4 receptor following binding of the test compound thereto. [0044] In one embodiment the agonist of the TLR4 receptor induces or upregulates signalling mediated by the TLR4 receptor. [0045] A further aspect of the present invention provides for the use of a compound identified according to the previous aspect of the invention in the preparation of a medicament of modulating the signalling mediated through the TLR4 receptor. In one embodiment signalling through the TLR4 receptor is upregulated. [0046] A further alternative embodiment of this aspect of the present invention provides an assay for identifying an antagonist of the TLR4 receptor, said assay comprising the steps of: providing a cellar sample including cells which express TLR4, exposing the cells to a test compound, detecting the phosphorylation of TRAM, wherein a decrease in the phosphorylation of TRAM in the presence of a test compound, when compared to the absence of a test compound is indicative of the test compound being an antagonist. [0050] In one embodiment the antagonist of the TLR4 receptor prevents or downregulates signalling mediated by the TLR4 receptor. [0051] In one embodiment, the assay further includes the step of exposing the cells to an agonist prior to exposure to the test compound. [0052] A further aspect of the present invention provides for the use of a compound identified according to the previous aspect of the invention in the preparation of a medicament of modulating the signalling mediated through the TLR4 receptor. In one embodiment signalling through the TLR4 receptor is upregulated. [0053] A yet further aspect of the invention provides a kit for the performance of an assay for the determination of the activation of TLR4, the kit including a sample, and instructions for performance of the assays in accordance with the fourth aspect of the invention. [0054] The inventors have, through substantial experimentation, identified that protein kinase C epsilon (PKCε) is the kinase which phosphorylates TRAM. Inhibition of phosphorylation by protein kinase C epsilon impairs the ability of TRAM to activate NK-κB and IFN-β. [0055] Accordingly a sixth aspect of the present invention provides an assay method for determining compounds which act as inhibitors of the function of protein kinase C epsilon, the methods comprising the steps of: providing a candidate compound, bringing the candidate compound into contact with protein kinase C epsilon, determining the presence or absence of the ability of protein kinase C epsilon to phosphorylate TRAM, wherein the absence of phosphorylation of TRAM is indicative of the blocking of the function of protein kinase C epsilon by the candidate compound. [0059] Directly inhibiting the protein kinase C epsilon molecule will not only prevent phosphorylation of TRAM but also inhibit the other cellular functions of protein kinase C epsilon. However the inventors have identified the specific domain of TRAM to which protein kinase C epsilon binds and this opens up the possibility of selective inhibition of phosphorylation of TRAM without causing the inhibition of other cellular functions of protein kinase C epsilon. [0060] Accordingly, an alternative embodiment of this aspect of the invention provides an assay for the identification of compounds which prevent the phosphorylation of TRAM by protein kinase C epsilon, said assay comprising the steps of: providing a candidate compound, bringing the candidate compound into contact with TRAM, exposing TRAM to protein kinase C epsilon in conditions suitable for phosphorylation to occur, and determining the presence or absence of phosphorylation of TRAM, wherein the absence of phosphorylation is indicative of the blocking of the interaction between protein kinase C epsilon and TRAM. [0065] In a preferred embodiment the compound selectively inhibits phosphorylation of TRAM by protein kinase C epsilon. [0066] In one embodiment the method includes the step of determining the ability of a compound to bind TRAM at or in the region of the domain corresponding to the serine 16 residue present on TRAM in order to prevent the phosphorylation of that serine residue by protein kinase C epsilon. [0067] In various further aspects, the present invention relates to screening and assay methods and to substances identified thereby. [0068] Novel compounds identified using the assays of the invention form a further independent aspect of the invention. Such compounds or modulators may be provided in pharmaceutical compositions. [0069] A modulator, or compound which modulates as identified according to the assays of the present invention may be a peptide or non-peptide molecule such as a chemical entity or pharmaceutical substance. Where the modulator is a peptide it may be an antibody, an antibody fragment, or a similar binding fragment. Further, where the modulator is an antibody, preferably it is a monoclonal antibody. [0070] A monoclonal antibody, antibody fragment or similar binding molecule with specificity for TRAM, which in particular binds to, or causes full or partial blocking of the serine-16 residue at the region to which protein kinase C epsilon binds in order to facilitate phosphorylate of TRAM has utility in the inhibition of the phosphorylation of TRAM and accordingly may prevent it facilitating downstream signalling activities following the binding of LPS to the TLR4 receptor. [0071] Accordingly a further aspect of the invention provides a specific binding member which comprises an antigen binding domain, wherein the antigen binding domain has specificity to the serine-16 residue of TRAM. [0072] In one embodiment the present invention provides an immunoglobulin which specifically binds or blocks binding to the serine-16 residue of TRAM. [0073] A yet further embodiment provides an immunoglobulin which prevents the phosphorylation of the serine-16 residue of TRAM by protein kinase C epsilon. [0074] Also encompassed within the scope of this aspect of the invention are specific binding members which bind to TRAM in order to prevent phosphorylation by protein kinase C epsilon. [0075] Endotoxins are composed of a lipopolysaccharide (LPS) complex which includes Lipid A and polysaccharide. LPS binds to the TLR4 receptor, this resulting in a downstream signalling cascade which induces an appropriate immune response. [0076] LPS-mediated or endotoxin-mediated conditions such as sepsis and septic shock can frequently result in mortality. Accordingly, a method of down-regulating or inhibiting the TLR4 mediated immune response pathway would be desirable as a treatment method for LPS mediated conditions such as sepsis. [0077] The present invention, through the observation that TRAM is phosphorylated by protein kinase C epsilon following LPS binding to TLR4 provides a potential route by which the interaction between LPS and intracellular kinases can be regulated. This may accordingly provide a powerful mechanism to disrupt LPS signalling. [0078] Accordingly the present invention may be used in the treatment of LPS-mediated conditions. [0079] The assay of the present invention and compounds of biological significance to the TLR4 signalling pathway which are realised by means of the use of said assay may have specific utility in the treatment in a number of medical conditions, most specifically endotoxin and LPS mediated conditions, for example sepsis. [0080] Accordingly, a seventh aspect of the present invention provides an assay for identifying compounds suitable for use in the treatment of endotoxin mediated conditions, said assay comprising the steps of: providing a candidate compound, bringing the candidate compound into contact with TRAM, determining the presence or absence of phosphorylation of TRAM by the candidate compound, wherein modulation of TRAM phosphorylation is indicative of the utility of that compound. [0084] In one embodiment the endotoxin mediated condition is sepsis or septic shock. [0085] A yet further aspect of the invention provides a method of treating LPS mediated conditions, said method comprising the step of inhibiting the phosphorylation of TRAM. [0086] In one preferred embodiment of this aspect of this invention, the inhibition of phosphorylation of TRAM is provided by blocking the binding of protein kinase C epsilon to TRAM. [0087] In one embodiment, blocking of the binding of protein kinase C epsilon to TRAM is facilitated by means of a compound which inhibits binding of protein kinase C epsilon to the serine 16 region where it effects phosphorylation. [0088] In a yet further embodiment, the compound binds directly to the serine-16 site at which protein kinase C epsilon effects phosphorylation of TRAM. Alternatively, the inhibitor binds to a site on TRAM which prevents protein kinase C epsilon accessing the binding site on TRAM required to facilitate phosphorylation of the serine-16 residue. [0089] The sequence of TRAM, is defined as SEQ ID NO:1 is: MGIGKSKINSCPLSLSWG. Serine 16 is the last serine in the sequence. [0090] Alternatively, a molecule is provided which competes with protein kinase C epsilon for binding to TRAM at a location suitable to phosphorylate the serine-16 residue. [0091] A further still aspect of the present invention provides a method of treating an LPS mediated condition such as sepsis in a subject comprising administering to said subject a therapeutically effective amount of a molecule which inhibits phosphorylation of TRAM. [0092] In one preferred embodiment of this aspect of the invention, the molecule prevents phosphorylation of TRAM by protein kinase C epsilon. [0093] The endotoxin mediated condition may, in particular, be caused by LPS which can result in fever, changes in white blood cell count, disseminated intravascular coagulation, hypotension, shock and death. [0094] In one preferred embodiment, the endotoxin mediated condition is sepsis. [0095] A further aspect of the present invention provides for the use of an inhibitor of protein kinase C epsilon in the preparation of a medicament for the treatment of an endotoxin mediated condition. [0096] Accordingly a further aspect of the invention provides a specific binding member which comprises an antigen binding domain, wherein the antigen binding domain has specificity to protein kinase C epsilon. [0097] In one embodiment the present invention provides an immunoglobulin which specifically binds or blocks binding to protein kinase C epsilon. [0098] A yet further aspect of the present invention provides for the use of an inhibitor of protein kinase C epsilon in the preparation of a medicament for the treatment of sepsis. [0099] A further still aspect of the present invention provides for the use of a compound which prevents the phosphorylation of TRAM in the preparation of a medicament for the treatment of an endotoxin mediated disease such as sepsis. [0100] A further still aspect of the invention provides a method of treating a medical condition using a compound identified by any one of the assay methods according to any one of the foregoing aspects of the present invention. [0101] Signalling mediated through the TLR4 receptor may also be involved with other immune responses aside those mediated by endotoxins. For example, signalling through the TLR4 receptor may be involved in inflammatory diseases, hence modulation of the ligand binding capacity of, and signal transduction by, and downstream of the TLR4 receptor may effect inflammatory diseases such as arthritis and atherosclerosis. In some autoimmune conditions, a candidate ligand or modulator of the TLR4 receptor has yet to be identified. However, in such instances, it would be suggested that endogenous factors made by inflamed or damaged tissue would act on the TLR4 receptor or its associated signalling pathway. [0102] Accordingly, a yet further aspect of the present invention provides an assay for identifying compounds suitable for use in the treatment or prophylaxis of an inflammatory or immune-mediated disorder, said assay comprising the steps of: providing a candidate compound, bringing the candidate compound into contact with TRAM, determining the presence or absence of phosphorylation of TRAM by the candidate compound, wherein modulation of TRAM phosphorylation is indicative of the utility of that compound. [0106] In preferred embodiments, the immune mediated disorder may be arthritis or atherosclerosis. [0107] A yet further aspect of the present invention provides for the use of an inhibitor of protein kinase C epsilon in the preparation of a medicament for the treatment or prophylaxis of an inflammatory condition or an immune-mediated disorder. [0108] A further still aspect of the present invention provides for the use of a compound which prevents the phosphorylation of TRAM in the preparation of a medicament for the treatment or prophylaxis of an inflammatory or immune-mediated disorder. [0109] In a still further aspect of the present invention, there is provided a method of treating a condition associated with signalling through the TLR4 receptor following binding thereto by LPS, in a patient in need of treatment thereof, said method comprising administration of a compound identified in accordance with any one of the assays of the present invention. [0110] Preferred features of each aspect of the invention are as for each of the other aspects mutatis mutandis unless the context demands otherwise. Assays [0111] The invention provides assay systems and screening methods for determining TRAM phosphorylation and further for monitoring TLR4 activation by means of the occurrence of TRAM phosphorylation. As used herein, an “assay system” encompasses all the components required for performing and analysing results of an assay that detects and/or measures a particular event or events. [0112] A variety of assays are available to detect the phosphorylation status of a target molecule or protein. [0113] In one embodiment, the assay will use a phosphor-specific antibody which is directed to the region of TRAM which undergoes phosphorylation. Most preferably, this antibody will bind to TRAM in the region of or proximal to the serine 16 residue. [0114] The amino acid sequence of TRAM, is defined as SEQ ID NO:1 which is as follows: MGIGKSKINSCPLSLSWG [0115] In a preferred embodiment, the assays of the invention will employ the technique known as Western Blotting. An antibody will be used in a Western Blot of samples from cells stimulated with a ligand to the TLR receptors, such as LPS, using standard methodology which will be well known to the man skilled in the art. [0116] In a further embodiment, the antibody can be used in other assay formats. For example, assays based on peptide fragments from TRAM could be used in in-vitro kinase assays instead of the whole protein. [0117] It is preferred, though not essential that the screening assays employed in the present invention are high throughput or ultra high throughput and thus provide an automated, cost-effective means of screening. DETAILED DESCRIPTION OF THE INVENTION Treatment [0118] The term ‘treatment’ as used herein refers to any regime that can benefit a human or non-human animal. The treatment may be in respect of an existing condition or may be prophylactic (preventative treatment). Treatment may include curative, alleviation or prophylactic effects. Pharmaceutical Compositions [0119] The present invention further extends to pharmaceuticals and to pharmaceutical compositions for the modulation of the phosphorylation of TRAM through an alteration of its phosphorylation state or through preventing its phosphorylation. [0120] Accordingly, a further aspect of the present invention provides a pharmaceutical composition for use in the modification of an immune response wherein the composition includes, as an active ingredient, a compound which modifies the phosphorylation of TRAM through promoting or blocking phosphorylation. [0121] Pharmaceutical compositions according to the present invention, and for use in accordance with the present invention may comprise, in addition to active ingredient, a pharmaceutically acceptable excipient, carrier, buffer stabiliser or other materials well known to those skilled in the art. [0122] Such materials should be non-toxic and should not interfere with the efficacy of the active ingredient. The precise nature of the carrier or other material will depend on the route of administration. Dose [0123] The composition is preferably administered to an individual in a “therapeutically effective amount”, this being sufficient to show benefit to the individual. The actual amount administered, and rate and time-course of administration, will depend on the individual and condition being treated. [0124] The optimal dose can be determined based on a number of parameters including, for example the age of the individual, the magnitude of the immune response to be inhibited or induced, the precise form of the composition being administered and the route of administration. [0125] The composition may be administered via microspheres, liposomes, other microparticulate delivery systems or sustained release formulations placed in certain tissues including blood. Suitable examples of sustained release carriers include semipermeable polymer matrices in the form of shared articles, e.g. suppositories or microcapsules. [0126] Examples of the techniques and protocols mentioned above and other techniques and protocols which may be used in accordance with the invention can be found in Remington's Pharmaceutical Sciences, 18th edition, Gennaro, A. R., Lippincott Williams & Wilkins; 20th edition (Dec. 15, 2000) ISBN 0-912734-04-3 and Pharmaceutical Dosage Forms and Drug Delivery Systems; Ansel, H. C. et al. 7 th Edition ISBN 0-683305-72-7 the entire disclosures of which is herein incorporated by reference. Antibodies [0127] In the context of the present invention, an “antibody” should be understood to refer to an immunoglobulin or part thereof or any polypeptide comprising a binding domain which is, or is homologous to, an antibody binding domain. [0128] An “antibody” is an immunoglobulin, whether natural or partly or wholly synthetically produced. The term also covers any polypeptide, protein or peptide having a binding domain that is, or is homologous to, an antibody binding domain. These can be derived from natural sources, or they may be partly or wholly synthetically produced. [0129] The antibody may be an intact antibody or a fragment thereof. Fragments of a whole antibody can perform the function of antigen binding. Examples of such binding fragments are (i) the Fab fragment consisting of VL, VH, CL and CH1 domains; (ii) the Fd fragment consisting of the VH and CH1 domains; (iii) the Fv fragment consisting of the VL and VH domains of a single antibody; (iv) the dAb fragment which consists of a VH domain; (v) isolated CDR regions; (vi) F(ab′)2 fragments, a bivalent fragment comprising two linked Fab fragments (vii) single chain Fv molecules (scFv), wherein a VH domain and a VL domain are linked by a peptide linker which allows the two domains to associate to form an antigen binding site; (viii) bispecific single chain Fv dimers and (ix) multivalent or multispecific fragments constructed by gene fusion. [0130] Antibodies can be modified in a number of ways and accordingly the term “antibody” should be construed as covering any binding member or substance having a binding domain with the required specificity. [0131] The antibody of the invention may be a monoclonal antibody, or a fragment, derivative, functional equivalent or homologue thereof. The constant region of the antibody may be of any suitable immunoglobulin subtype. [0132] The term “antibody” includes antibodies which have been “humanised” or produced using techniques such as CDR grafting. Such techniques are well known to the person skilled in the art. Production of Antibodies [0133] Specific binding members of and for use in the present invention may be produced in any suitable way, either naturally or synthetically. Such methods may include, for example, traditional hybridoma techniques, recombinant DNA techniques, or phage display techniques using antibody libraries. Such production techniques would be known to the person skilled in the art, however, other antibody production techniques are described in Antibodies: A Laboratory Manual, eds. Harlow et al., Cold Spring Harbor Laboratory, 1988. [0134] Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by a person who is skilled in the art in the field of the present invention. [0135] Throughout the specification, unless the context demands otherwise, the terms ‘comprise’ or ‘include’, or variations such as ‘comprises’ or ‘comprising’, ‘includes’ or ‘including’ will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. [0136] The present invention will now be described with reference to the following examples which are provided for the purpose of illustration and are not intended to be construed as being limiting on the present invention, and further, with reference to the figures. BRIEF DESCRIPTION OF THE DRAWINGS [0137] FIG. 1 : TRAM was cloned from cDNA using (a) primers targeting the 5′ and 3′ ends of TRAM and (b) the resulting PCR product was cloned into several vectors. (c) Site directed mutagenesis was performed using specific primers to mutate the first 4 serines in TRAM to alanines and to mutate the serine at position 16 alone to an alanine. [0138] FIG. 2 : (a) GST-TRAM is phosphorylated upon incubation with THP1 lysates that have been treated with LPS for varying lengths of time. (b) This phosphorylation of TRAM does not occur when the cells are treated with PolyI:C. (c) This LPS-dependent phosphorylation is abolished when the first 4 serines of TRAM are mutated to alanines. (d) Following GST-TRAM pulldowns with lysates from THP1 cells treated for 30 min with LPS, the samples were incubated with increasing amounts of the pan PKC inhibitor, Bisindolylmaleimide (Bis), for 1 hour. This caused a decrease in the phosphorylation of TRAM. (e) Immunodepletion of the THP1 lysates was performed using a PKCε antibody, a PKCζ antibody or an IgG control antibody prior to incubation with the GST-TRAM. Removal of PKCε from the lysates prevented LPS-dependent phosphorylation of TRAM. (f) Lysates taken from PKCε-deficient MEFs cannot phosphorylate GST-TRAM while MEFs reconstituted with PKCζ can. (g) Recombinant PKCε (rePKCε) or PKCζ (rePKCζ) was incubated directly with GST-TRAM for 15 minutes prior to a kinase assay being performed. rePKCε phosphorylated WT-TRAM but not Mal. [0139] FIG. 3 : (a) When the serine at position 16 is mutated to an alanine, GST-TRAM can no longer be phosphorylated following incubation with THP1 lysates. (b) pcDNA3.1 alone (eV), WT-TRAM/pcDNA3.1 and Ser16-TRAM/pcDNA3.1 were all transfected into HEK293 cells seeded in 96-well plates. The NF-κB or ISRE-luciferase reporter gene and the Renilla luciferase internal control plasmid were also transfected in. 24 hours later the reporter gene activity was measured and the data expressed as mean fold stimulation relative to control levels. The graph shows that WT-TRAM can activate both the NF-κB and ISRE pathways while the Ser16-TRAM mutant cannot activate either pathway. (c) a similar experiment was then carried out in HEK293-TLR4 cells and 24 hours post transfection the cells were incubated with and without LPS (1 μg/ml) for 6 hours. The results show that WT-TRAM increases the ability of LPS to activate both NF-κB and ISRE while the Ser16-TRAM mutant acts as a dominant negative and reduces the ability of LPS to stimulate NF-KB and ISRE. (d) HEK293 cells were incubated with and without the PKC inhibitor, Bisindolylmaleimide (Bis), for 1 hour prior to transfection with pcDNA3.1, MyD88/pcDNA3.1 or WT-TRAM/pcDNA3.1 and the NF-κB-luciferase reporter gene and Renilla luciferase internal control plasmid. The inhibitor had no effect on the ability of MyD88 to activate the NF-κB pathway but it inhibited the ability of TRAM to activate this pathway. [0140] FIG. 4 shows that TRAM is phosphorylated on the Serine 16 residue. (a) HEK293-TLR4 cells overexpressing FLAG-tagged TRAM were stimulated with 1 μg/ml LPS for 30 min. FLAG-tagged TRAM was immunoprecipitated using an antibody to FLAG and blotted with a phosphoserine antibody. (b) THP1 cells incubated with and without the PKC inhibitor BIS for 1 hour prior to stimulation with LPS, (c) PKCε −/− MEFs and PKCε −/− MEFs that had been reconstituted with PKCε following stimulation with 1 μg/ml LPS for the indicated lengths of time and (d) PKCε −/− MEFs and PKCε −/− MEFs that had been reconstituted with PKCε following stimulation with LPS, polyI:C or MALP2 for 30 minutes. [0141] FIG. 5 shows that TRAM and PKCε are both essential for complete LPS signaling. (a) Cells from PKCε −/− MEFs and PKCε −/− MEFs that had been reconstituted with PKCε (top four panels) or TRAM −/− MEFs and WT MEFs (bottom four panels) were stimulated for the indicated times with 1 μg/ml LPS or 5 μg/ml PolyI:C and the lysates were immunoblotted for phosphorylated (Tyr 180/182) and total p38. (b)—PKCε −/− MEFs and PKCε −/− MEFs that had been reconstituted with PKCε were treated with 1 μg/ml LPS or 5 μg/ml polyI:C for the indicated times, run on a non-reducing PAGE gel and immunoblotted for IRF3. (c) The ISRE luciferase reporter gene and the control Renilla luciferase reporter gene were transfected into the above cell types. 24 hours post-transfection the cells were stimulated with 1 μg/ml LPS or 5 μg/ml PolyI:C for 6 hours. The data represents mean fold stimulation of luciferase activity relative to control levels. (d), (e) The above cell types were stimulated with the indicated concentrations of LPS or PolyI:C for 24 hours and then a RANTES ELISA was performed. Results shown are representative of at least three experiments. [0142] FIG. 6 : TRAMS16A is attenuated relative to WT TRAM in reconstituting TRAM-deficient MEFs. WT TRAM, TRAMS16A and empty vector were transfected into TRAM-deficient MEFs. 24 hours post transfection. (a) Cells were stimulated with LPS (1 μg/ml) for a further 24 h and the culture supernatants were assayed for RANTES by ELISA. (b) Cells were stimulated with LPS (1 μg/ml) for 30 minutes and the lysates were assayed for p38 by western blot. Results shown are representative of at least three experiments. [0143] FIG. 7 shows that the amount of TRAM present in the membrane fraction was decreased upon LPS stimulation suggesting that TRAM is disappearing from the membrane. [0144] FIG. 8 shows when the serine 16 residue was mutated to a glutamic acid, this mutation caused a significant decrease in the amount of TRAM present in the membrane ( FIG. 8 a , compare lane 3 to 1) suggesting that the phosphorylation of TRAM on Serine 16 causes depletion of TRAM from the membrane, and further that depletion of endogenous TRAM in THP1 cells treated with LPS ( FIG. 8 b ) was also detected, and further that PKCε−/− MEFs FLAG-TRAM did not become depleted from the membrane upon LPS stimulation ( FIG. 8 c ). This evidence suggests that the phosphorylation of TRAM on Serine 16 by PKCε is required for TRAM to be depleted from the membrane. EXAMPLES Materials and Methods [0145] Cells: HEK293 cells and HEK293 cells stably transfected with TLR4 (HEK293-TLR4) were cultured in Dulbecco's Modified Eagles medium (DMEM) supplemented with 10% Fetal calf serum (FCS), 100 Units/ml penicillin, 100 mg/ml streptomycin and 2 mM Glutamine. THP1 cells were cultured in RPMI supplemented with 10% FCS, 100 Units/ml penicillin, 100 mg/ml streptomycin and 2 mM Glutamine. [0146] Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR): cDNA was generated using spleen mRNA (BD Biosciences) as a template. 1-5 μg RNA was incubated with 0.1 μg random primers and brought to a final volume of 5 μl with DEPC-treated water. [0147] This was incubated at 70° C. for 10 min and then 4° C. for 2 min. Reverse transcription was carried out using the moloney murine leukemia virus reverse transcriptase (MMLV-RT) enzyme. 4 μl 5× buffer (250 mM TrisCl pH 8.3, 375 mM KCl and 15 mM MgCl 2 ) was added along with 2 μl 100 mM DTT, 1 μl RNasin (40 unit/ml), 1 μl 10 mM dNTP, 1 μl MMLV-RT (200 unit/μl) and 6 μl DEPC-treated water. This reaction was incubated at 37° C. for 1 hour and then 95° C. for 2 min to inactivate the enzyme. 5 μl of this reaction was used as a template for a PCR reaction using specific primers to the 5′ and 3′ ends of TRAM. 1×DNA polymerase buffer (1 mM TrisCl pH 9.0, 5 mM KCl and 0.01% Triton® X-100), 0.2 mM of each dNTP, 2.5 u Taq DNA polymerase, 0.5 μM of each specific oligonucleotide primer and 0.5-3 mM MgCl 2 were added to the template DNA and the reaction mix was made up to a final volume of 50 μl using PCR grade water. 30 cycles of 94° C. for 1 min, 55° C. for 1 min and 72° C. for 2 min were performed in a thermal cycler. The PCR products were analysed by agarose gel electrophoresis. [0148] Cloning of TRAM into a GST expression vector and a mammalian expression vector: The TRAM PCR product was ligated into the pGEX-KG vector (Pharmacia) and into the pcDNA3.1 vector (Invitrogen). Firstly, the PCR product and vector were digested in separate reactions. 5-10 unit restriction endonuclease (NEB), 1× restriction enzyme buffer, ±1×BSA and 1-10 μg DNA were made up to 10 μl with sterile water and incubated at 37° C. for 2 hours. The digested products were then purified using a PCR purification kit (Qiagen). A ligation reaction consisting of 1 unit T4 DNA ligase (1 unit/μl) (Promega), 2 μl T4 10× reaction buffer, 100-150 ng digested vector DNA and 200-400 ng digested PCR product, was made up to 20 μl with sterile water. This ligation mixture was left overnight at 4° C. and then transformed into BL21(DE3) cells (Stratagene). [0149] Site directed mutagenesis of TRAM: The Quickchange® site directed mutagenesis kit (Stratagene) was used to mutate certain bases in the TRAM gene. The manufacturer's instructions were followed using primers containing the desired mutation. [0150] Expression and purification of GST-TRAM: The BL21(DE3) containing the TRAM-pGEX vector were grown overnight at 37° C. in 10 ml LB broth in a shaking incubator. The next day the 10 ml was placed in 500 ml LB broth and grown to an OD of 0.6-0.8. IPTG was added to the culture to a final concentration of 0.2 mM and this culture was incubated at 30° C. for a further 4 hours. The culture was then spun down in a GSA rotor in a Sorvall RC5C centrifuge at 8,000 rpm for 15 min. The pellet was resuspended in 25 ml of NETN buffer (20 mM Tris-Cl, 100 mM NaCl, 1 mM EDTA, 0.5% NP40, 10 μg/ml leupeptin, 10 μg/ml pepstatin, 1 mM PMSF, pH 8.0), sonicated for 5 min using a sonicator (Branson Sonifer 250) and centrifuged at 18,000 rpm for 45 min. The supernatant was added to 6001 Glutathione sepharose beads (Amersham) and incubated at 4° C. for 2 hours. The beads were then washed 5 times in 15 ml NETN buffer and resuspended in 600 μl NETN buffer. [0151] Luciferase reporter gene assays: HEK293 or HEK293-TLR4 cells were seeded in 96 well plates at a density of 1×10 5 cells/ml. The following day the cells were transfected with the luciferase reporter plasmid of choice and the expression vectors of choice using Genejuice (Novagen), following the manufacturer's instructions. For experiments involving the detection of NF-κB and IRF3 activation, 80 ng of the NF-κB or IRSE-luciferase reporter gene (Stratagene) were transfected into the cells along with 40 ng of the Renilla luciferase internal control plasmid (Stratagene). After 24 hours the cells were lysed in passive lysis buffer (Promega) and reporter gene activity was measured using a luminometer. The data was expressed as mean fold stimulation relative to control levels. [0152] Kinase assay: THP1 cells were seeded at 2×10 5 cells/ml in a T175 flask (Sarstedt) and incubated overnight at 37° C. The following day 30 ml of cells were treated with and without LPS in 50 ml falcon tubes (Sarstedt) for 1 hour. The cells were collected by centrifugation, washed once in PBS and lysed in 1 ml buffer (10% glycerol (v/v), 50 mM NaF, 20 mM Tris-Cl pH 8.0, 2 mM EDTA, 137 mM NaCl, 1% NP-40, 1 mM PMSF, 10 μg/ml leupeptin, 1 mM Na 3 VO 4 ) for 10 minutes. The cell debris was centrifuged for 10 min at 13,000 rpm and the supernatant was removed to a fresh tube for use in the kinase assay. 50 μl of the purified GST-TRAM on the Glutathione beads was placed in an eppendorf tube and the appropriate lysate was added to the tube and incubated for 2 hours at 4° C. The beads were spun down at 2,000 rpm for 5 min and then washed three times in kinase buffer (20 mM HEPES, pH 7.5, 10 mM MgAc, 0.03% Trition, 100 μg/ml phosphotidylserine, 20 mM β-glycerol phosphate, 0.01% (w/v) leupeptin and 100 μM Na 3 VO 4 ). These beads were then resuspended in 30 μl kinase buffer containing 20 μM cold ATP and 5 μCi [γ 32 P] ATP and incubated at 37° C. for 30 min. 20 μl sample buffer (50 mM Tris-Cl, pH 6.8, 10% glycerol (v/v), 2% SDS (w/v), 0.1% bromophenol blue (w/v) and 5% β-mercaptoethanol) was added to the tube and the sample was boiled for 5 mins. The sample was then run on a 10% SDS-PAGE gel and transferred to nitrocellulose. The nitrocellulose was placed in a autorad cassette (Kodak) and an piece of X-ray film was placed on top. This was left at −80° C. overnight and the film was then developed. [0153] Membrane fractionation: HEK293-TLR4 cells were seeded at 1×10 5 cells/ml overnight and then transfected with the appropriate plasmids. 24 hrs post-transfection the cells were treated as directed in the results section and then scrapped into 300 μl of membrane buffer (20 mM Tris, pH 7.5, 10 mM MgCl 2 , 1 mM EDTA, 250 μM sucrose, 200 μM PMSF). The cells were lysed using 30 strokes of a dounce homogenizer and spun in hardwall Beckman tubes at 100,000 rpm for 1 hr at 4° C. The supernatant, i.e. the cytosolic fraction, was removed to a fresh tube and the pellet, i.e. the membrane fraction, was resuspended in 50 μl sample buffer (50 mM Tris-Cl, pH 6.8, 10% glycerol (v/v), 2% SDS (w/v), 0.1% bromophenol blue (w/v) and 5% β-mercaptoethanol). The cytosolic fraction was concentrated down to 50 μl using a centricon YM-10 (Millipore). The samples were run on a 12% SDS-PAGE gel. Production of a Phospho-Specific TRAM Antibody [0154] Fabgennix (Texas, USA), using a synthetic peptide corresponding to amino acids 7 to 21 of TRAM (KIN SCP LSL SWG KRH) with a phosphoserine incorporated instead of the serine at amino acid 16, generated and purified a phospho-specific antibody towards TRAM phosphorylated on Serine 16. The validity of the antibody was confirmed when the band predicted to the phosphorylated TRAM was not present in samples taken from TRAM-deficient MEFs (data not shown). RANTES ELISA [0155] The indicated cells were seeded at 1×10 5 cells/ml overnight in 24 well plates and then transfected with the appropriate plasmids. 24 hours post-transfection the cells were treated with the appropriate stimuli for 24 hours. Using a 1 in 5 dilution of the supernatant as the sample, a RANTES ELISA was performed, using the R&D systems' mouse RANTES kit, following the manufacturer's instructions. IRF3 Dimerisation Assay [0156] The appropriate cells were seeded at 2×10 5 cells/ml overnight and then treated with the appropriate stimuli. The cells were washed in PBS and scrapped into 100 μl non-reducing sample buffer (50 mM Tris-Cl, pH 6.8, 10% glycerol (v/v), 0.1% bromophenol blue (w/v) and 5% β-mercaptoethanol). 20 μl of this was run on a non-reducing PAGE gel, transferred onto nitrocellulose and blotted for IRF3. Results [0157] Cloning of the TRAM gene and generation of mutants: The cDNA sequence from TRAM was retrieved from Genebank (Accession number NM — 021649). Specific primers to the 5′ and 3′ end of TRAM ( FIG. 1 a ) were used to amplify up the TRAM cDNA using mRNA generated from the spleen ( FIG. 1 b ). This cDNA was cloned into the pGEX-KG vector to allow for expression of a GST-TRAM fusion protein in bacteria. It was also cloned into the mammalian expression vector pcDNA3.1. To generate mutants of TRAM site directed mutagenesis was performed. Primers were designed ( FIG. 1 c ) to allow for the mutation of the serines at position 6, 10, 14 and 16 (called 4Ser mutant). Primers were also designed to mutate Serine 16 alone (called Ser16 mutant). [0158] TRAM is phosphorylated upon LPS stimulation: TRAM is myristoylated, and in resting cells is located in the membrane (unpublished data). Several myristoylated proteins undergo an electrostatic switch which involves them being phosphorylated and repelled from the membrane. An assay was therefore devised to determine if TRAM was phosphorylated. Purified GST-TRAM on glutathione beads was incubated for 2 hours with lysates from THP1 cells, that had been treated with and without LPS. The samples were then centrifuged causing GST-TRAM on the glutathione beads, along with any proteins it interacted with, to be pulled down. A kinase assay was then performed, by incubating the beads with [γ 32 P] ATP for 30 minutes. The samples were then run on a 10% SDS-PAGE gel, transferred onto nitrocellulose and the incorporated radioactivity was measured using X-ray film. The results ( FIG. 2 a ) show that TRAM is indeed phosphorylated and that this phosphorylation is LPS dependent. This phosphorylation did not occur when the cells were treated with other stimuli, such as PolyI:C ( FIG. 2 b ). [0159] 4 serines closest to the N terminus were identified. These 4 serines were subsequently mutated. [0160] Following this mutation, LPS dependent phosphorylation was abolished ( FIG. 2 c ). Phosphorylation of TRAM [0161] Protein Kinase C has been shown to phosphorylate the myristoylated protein, MARCKS, so to investigate if TRAM was phosphorylated by PKC, the pan PKC inhibitor bisindolylmaleimide (Bis) was used. As above, GST-TRAM was incubated with lysates from THP1 cells, treated with LPS and was pulled down using Glutathione beads. Increasing amounts of Bis were added to the beads for 1 hour and then the kinase assay was performed as above. Bis inhibited LPS dependent phosphorylation of TRAM ( FIG. 2 c ). This strongly indicated that a member of the PKC kinase family was responsible for phosphorylation of TRAM in response to LPS. [0162] Immunodepletion of the THP1 lysates was perform by incubating the lysates with a PKCε specific antibody (Santa Cruz) attached to protein G beads (Sigma). A PKC zeta (PKCζ) antibody was used as a control to check for specificity. The antibody was removed by centrifugation, removing PKCε or PKCζ from the lysates. A control IgG antibody was also used. These lysates were then incubated with GST-TRAM as above and a kinase assay was performed. FIG. 2 e shows that the removal of PKCε from the lysates abolishes the phosphorylation of TRAM. This suggests that PKCε is phosphorylating TRAM in response to LPS. The removal of PKCζ had no effect on the phosphorylation of TRAM suggesting that PKCζ does not phosphorylate TRAM. This theory was further strengthened by the fact that recombinant PKCε (rePKCε) (Calbiochem) phosphorylated GST-TRAM ( FIG. 2 g ) and lysates from PKCε-deficient MEFs could not phosphorylate GST-TRAM ( FIG. 2 f ). Recombinant PKCζ did not phosphorylate TRAM again suggesting specificity ( FIG. 2 g ). Serine 16 is a candidate for PKCε phosphorylation so we mutated serine 16 to an alanine and found that the LPS dependent phosphorylation of TRAM was severally impaired ( FIG. 3 a ). [0163] As the serine at position 16 is the only one of four serines that is conserved in the mouse, this serine was mutated. LPS dependent phosphorylation of TRAM was severally impaired ( FIG. 3 a ). [0164] To investigate if this phosphorylation of TRAM was essential for it to function properly, the serine at position 16 was mutated to an alanine and the ability of this mutant to drive the NF-κB and IRF3 pathways was investigated. WT-TRAM or the Ser16-TRAM were transfected into HEK293 cells along with either the NF-κB or ISRE-luciferase reporter gene. As shown previously, TRAM can drive both NF-κB and ISRE luciferase. However, when the Serine 16 was mutated TRAM could no longer activate either pathway ( FIG. 3 b ). [0165] Mutating the Serine 16 also reduced the ability of LPS to stimulate the NF-κB and ISRE pathways ( FIG. 3 c ). This mutant must act as a dominant negative on these pathways. Further evidence that phosphorylation of TRAM by PKC is essential for it to function correctly is the fact that the PKC inhibitor, Bisindolylmaleimide, inhibits the ability of TRAM to activate the NF-κB pathway but has no effect on MyD88 ( FIG. 3 d ). This evidence suggests that Serine 16 needs to be phosphorylated by PKCε for TRAM to function properly. [0166] In order to confirm that phosphorylation of the serine 16 residue was sufficient to allow TRAM to leave the membrane, the serine 16 residue was mutated to a glutamic acid. The resulting mutant (ser16Glu) served as a positive glycosylation control, wherein the glutamic acid residue mimics the serine residue when it is in a glycosylated state. This mutation caused a significant decrease in the amount of TRAM present in the membrane ( FIG. 8 a , compare lane 3 to 1) suggesting that the phosphorylation of TRAM on Serine 16 causes depletion of TRAM from the membrane. [0167] Depletion of endogenous TRAM in THP1 cells treated with LPS ( FIG. 8 b ) was also detected. Finally, in PKCε−/− MEFs FLAG-TRAM did not become depleted from the membrane upon LPS stimulation ( FIG. 8 c ). This evidence suggests that the phosphorylation of TRAM on Serine 16 by PKCε is required for TRAM to be depleted from the membrane. Endogenous TRAM is Phosphorylated on Serine 16 [0168] We tested phosphorylation of overexpressed TRAM using a phosphoserine antibody. HEK293-TLR4 cells transfected with FLAG-TRAM and stimulated with LPS. FLAG-TRAM was immunoprecipitated from the cells and lysates were blotted with an anti-phosphoserine antibody. As can be see from FIG. 4 a , TRAM showed an increase in serine phosphorylation in cells treated with LPS for 30 minutes. [0169] In order to establish whether endogenous TRAM is phosphorylated on serine 16 by PKCε, an antibody was raised to a synthetic peptide comprising of amino acid 7 to 21 of TRAM with a phosphoserine inserted instead of a serine at amino acid 16. [0170] Immunoblotting lysates from THP1 cells treated with LPS, showed TRAM phosphorylation on serine 16 appearing after 15 minutes and peaking at 45 minutes ( FIG. 4 b , lane 1-6). Incubation of these cells with the PKC inhibitor BIS for 1 hr prior to stimulation with LPS prevented the phosphorylation of TRAM ( FIG. 4 b , lane 7-12). Immunoblotting of lysates from PKCε −/− MEFs reconstituted with PKCε, treated with LPS for 15 and 30 minutes, revealed a band of the correct molecular weight as TRAM ( FIG. 4 c , top panel, lane 9 and 10). The phosphorylation occurred earlier in this cell type than the THP1 cells as the effect was waning by 45 minutes (lane 11) and was not evident at 60 minutes (lane 12). Levels of total TRAM were not altered in the lysates over the time course ( FIG. 4 c , second panel). Importantly no band was detected in lysates generated from PKCε −/− MEFs ( FIG. 4 c , top panel, lane 1-6) and no bands were detected in TRAM-deficient cells attesting to the specificity of the antibody (data not shown). Finally treatment of PKCε expressing MEFs with the TLR2 ligand MALP2 or the TLR3 ligand polyI:C for 30 minutes had no effect ( FIG. 4 d ). Tram and PKCε are Both Essential for Complete LPS Signaling [0171] TRAM-dependent signaling in PKCε −/− MEFs was then tested. In both TRAM −/− MEFs and PKCε −/− MEFs the phosphorylation of p38 in cells treated with LPS was significantly reduced in comparison to their corresponding wild-type MEFs ( FIG. 5 a top panel compare lanes 9-11 to 3-5). Importantly, there was no reduction in p38 phosphorylation in response to polyI:C in PKCε −/− MEFs or TRAM −/− MEFs ( FIG. 5 a panel 3, compare right and left hand sides). We also tested the activation of IRF3 by LPS as indicated by its dimerisation. IRF3 dimerisation induced by LPS was reduced in PKCε −/− MEF relative to MEFs expressing PKCε ( FIG. 5 b , compare lane 2 and 3 to lane 4 and 5). There was no reduction in IRF3 dimerisation in PKCε −/− MEF in response to polyI:C ( FIG. 5 c , compare lane 2 and 3 to lane 4 and 5). As shown by Yamamoto et al. this response was also impaired in TRAM-deficient MEFs in response to LPS but not polyI:C. Activation of an IRF3-linked reporter gene was tested and this was impaired in LPS-treated PKCε −/− MEFs but was normal in polyI:C-treated PKCε −/− MEFs ( FIG. 5 c , right panel). Similar results were obtained in TRAM-deficient MEFs. Induction of RANTES was then assessed as a readout for the TRAM pathway. In TRAM −/− MEFs the levels of RANTES produced in response to LPS stimulation was dramatically reduced in comparison to the corresponding wild type MEFs ( FIG. 5 d , left panel). The levels of RANTES production in response to polyI:C was not affected ( FIG. 5 d , right panel). Importantly, this response was also impaired in PKCε −/− cells. As shown in FIG. 5 e (left panel), induction of RANTES by LPS was impaired relative to PKCε expressing cells. There was no difference in the response to polyI:C when both cells types were compared ( FIG. 5 e , right panel). [0172] As the production of RANTES is a marker associated with the TRAM signalling pathway, the impairment in its production in PKCε −/− cells and TRAM −/− MEFs cells further supports the observation that TRAM must be phosphorylated by protein kinase C epsilon and that this phosphorylation is essential for its function. TRAMS16A is Unable to Fully Reconstitute Signaling in TRAM-Deficient Cells [0173] The clear impairment in TRAM-dependent responses following LPS treatment in PKCε −/− cells, with the same responses being intact in polyI:C-treated cells, coupled with impaired signaling by TRAMS16A, strongly suggested that TRAM phosphorylation by PKCε is essential for TRAM function. To provide further evidence for this we examined the ability of TRAMS16A to reconstitute signaling in TRAM-deficient MEFs. Treatment of wild type MEFs with LPS, induced RANTES production while treatment of TRAM −/− MEFs with LPS caused little or no induction of RANTES production ( FIG. 6 a ). The response of the TRAM-deficient cells could be reconstituted with wild type TRAM. Significantly, TRAMS16A was less capable of reconstituting the signal however Similarly, the phosphorylation of p38 in TRAM-deficient cells upon LPS stimulation was reconstituted with overexpression of WT TRAM. TRAMS16A could not reconstitute this signal ( FIG. 6 b ). It is therefore concluded that phosphorylation of Serine 16 by protein kinase C epsilon must be required for TRAM to function normally upon LPS stimulation. Levels of TRAM in the Membrane are Reduced Upon LPS Stimulation [0174] The myristoylation of TRAM promotes membrane localization. It is known that certain myristoylated proteins dissociate from the membrane upon phosphorylation. It was further investigated whether phosphorylation of TRAM by PKCε would cause a redistribution of TRAM. [0175] FLAG-TRAM/pcDNA3.1 was transfected into HEK293-TLR4 cells and these cells were then stimulated with or without LPS for 30 minutes. The cells were fractionated into membrane and cytosolic fractions. The amount of TRAM present in the membrane fraction was decreased upon LPS stimulation suggesting that TRAM is disappearing from the membrane ( FIG. 7 a , top panel compare lane 3 to lane 1). TRAM could not be detected in the cytosolic fraction. This was not due to degradation, since the levels of TRAM in the cell lysates remained constant ( FIG. 7 a , third panel). The depletion of TRAM from the membrane was PKCε dependent, since the addition of the PKC inhibitor BIS 1 hour prior to LPS stimulation caused FLAG-TRAM to remain in the membrane even after LPS stimulation ( FIG. 7 a , lane 7). When tested for depletion of TRAMS16A, no depletion from the membrane was observed ( FIG. 7 a , second panel). Depletion of endogenous TRAM in THP1 cells treated with LPS ( FIG. 7 b ) was also detected. Finally, in PKCε −/− MEFs FLAG-TRAM did not become depleted from the membrane upon LPS stimulation ( FIG. 7 c ). This evidence suggests that the phosphorylation of TRAM on Serine 16 by PKCε is required for TRAM to be depleted from the membrane. SUMMARY [0176] TRAM acts as a bridging adaptor between TLR4 and Trif and plays a vital role in the signalling cascade activated by LPS. TRAM is myristoylated and this allows it to associate with the plasma membrane. TRAM is also phosphorylated. [0177] In response to LPS, TRAM becomes phosphorylated and this can be measured in-vitro using a kinase assay described here. This phosphorylation is vital for TRAM to function normally and may be involved in an electrostatic switch, allowing TRAM to move out of the membrane. [0178] All documents referred to in this specification are herein incorporated by reference. Various modifications and variations to the described embodiments of the inventions will be apparent to those skilled in the art without departing from the scope of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes of carrying out the invention which are obvious to those skilled in the art are intended to be covered by the present invention. REFERENCES [0000] 1. Janeway, C. A., Jr., Medzhitov, R., 2002 . Annu Rev Immunol 20, 197-216. 2. Dunne A., O'Neill, L. A., 2003a. Sci STKE 2003, re3. 3. Doyle, S. et al. (2002) Immunity 17, 251-63. 4. Poltorak A. et al. (1998) Science 282, 2085-8. 5. Qureshi S. T. et al. (1999) J Exp Med 189, 615-25. 6. Takeda K., Takeuchi O. and Akira S. (2002) J Endotoxin Res 8, 459-63. 7. Alexopoulou L. et al. (2001) Nature 413, 732-8. 8. Hayashi F. et al. (2001) Nature 410, 1099-103. 9. Hemmi H. et al. (2000) Nature 408, 740-5. 10. Hemmi H. et al. (2002) Nat Immunol 3, 196-200. 11. Adachi O. et al. (1998) Immunity 9, 143-50. 12. Takeuchi O. et al. (2000) J Immunol 164, 554-7. 13. McGettrick A. F. and O'Neill L. A. (2004) Mol Immunol 41, 577-82. 14. Fitzgerald, K. A. et al. (2001) Nature 413, 78-83. 15. Horng, T. et al. (2001) Nat Immunol 2, 835-41. 16. Horng, T. et al. (2002) Nature 420, 329-33. 17. Yamamoto, M. et al. (2002) J Immunol 169, 6668-72. 18. Oshiumi, H. et al. (2003) Nat Immunol 4, 161-7. 19. Yamamoto, M. et al. (2003) Science 301, 640-3. 20. Fitzgerald, K. A. et al. (2003) J Exp Med 198, 1043-55. 21. Oshiumi, H. et al. (2003) J Biol Chem 278, 49751-49762. 22. Bin, L. H. et al. (2003) J Biol Chem 278, 24526-32. 23. Yamamoto, M. et al. (2003) Nat Immunol 4, 1144-50. 24. Thelen M. et al. (1991) Nature 351, 320-2. 25. Aderem A. A. et al. (1988) Nature 332, 362-4. 26. Wu W. C. et al. (1982) Proc Natl Acad Sci USA 79, 5249-53. 27. Rozengurt E. et al. (1983) Proc Natl Acad Sci USA 80, 7244-8. 28. Rozengurt E. and Sinnett-Smith J. (1983) Proc Natl Acad Sci USA 80, 2936-40. 29. Graff J. M. et al. (1989) Science 246, 503-6. 30. Rosen A. et al. (1990) J Exp Med 172, 1211-5. 31. Matsubara M. et al. (2003) J Biol Chem 278, 48898-902. 32. Takasaki A. et al, (1999) J Biol Chem 274, 11848-53. 33. Hayashi N., et al. (2000) Protein Sci 9, 1905-13.

Disclosed are assays for the determination and quantification of the phosphorylation of TRAM (Trif-related adaptor molecule). TRAM is rapidly phosphorylated upon LPS stimulation by protein kinase C epsilon (PKCε) and that this phosphorylation is vital for TRAM to function normally. Assays suitable for detecting the state of phosphorylation of TRAM have utility in identifying compounds which have activity in modulating TRAM. Further disclosed are compounds which have utility in modulating the phosphorylation of TRAM to modulate signalling mediating by the Toll Like Receptor 4 (TLR4) receptor.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION [0001] This application relates to roll-out waste bins, and more particularly to a feature on the exterior of such a roll-out waste bin that permits the bin to be lifted by an automated lifter mounted on a waste disposal truck for emptying into the waste collection hopper of the truck, and then to be lowered back to the ground. Such bins generally include a large receptacle mounted on wheels with a hinged lid for closing the receptacle except during loading or emptying. The front of the bin includes a retention bar which, in conjunction with a downward lip along the front top rim of the waste bin, is gripped by the automated lifter in order to lift and dump the contents of the waste bin. In typical prior art waste bins a retention bar receiving area is provided on the exterior of the waste bin which holds the retention bar. In its most basic form, this receiving area is formed of two parallel, vertical walls, external to the interior volume of the waste bin, set apart at a distance that is less than the length of the retention bar. See FIG. 1 . Each of these vertical walls has an aperture through which the retention bar is placed, with enough clearance to allow the retention bar to spin freely. See FIG. 1A . [0002] Another embodiment of this receiving area has front closeout walls that connect the vertical walls to the waste bin receptacle, thereby creating two retention bar housings, each housing having one vertical wall, one front closeout wall and two external walls of the waste bin receptacle. See FIGS. 2 , 2 A. [0003] A pair of ribs, one residing inside each of the retention bar housings extend from one of the external walls of the retention bar housings. These ribs trap the retention bar after it has been slid into position through the retention bar housing apertures, preventing the retention bar from moving side-to-side enough to be removed. The ribs are positioned in the retention bar housings to normally interfere with the retention bar and thereby prevent the retention bar from being pulled free of free of the bin. In order to insert the retention bar, these ribs have a suitable degree of flexibility, and are typically bent by the retention bar sufficiently to allow the retention bar to slide past the ribs and enter the retention bar housings, whereupon the ribs spring back into their normal positions, locking the retention bar into the retention bar housings. [0004] This arrangement requires considerable maneuvering to insert the retention bar into both apertures, past the ribs and into the retention bar housings. [0005] This application also discloses a method of installing a retention bar onto a waste bin. SUMMARY OF THE INVENTION [0006] It is therefore an object of the present invention to provide a roll-out waste bin that is provided with a retention bar that is simple to install, and that remains securely positioned in its required position. [0007] It is another object of the invention to provide a roll-out waste bin that is provided with a retention bar that can be inserted and retained on the bin, thereby utilizing simplified retention devices. [0008] It is another object of the invention to provide a roll-out waste bin that is provided with a retention bar that can be inserted and retained on the bin utilizing a rib on one side of the retention bar and other retention means on the other side of the retention bar. [0009] It is another object of the invention to provide a method of installing a retention bar onto a waste bin. [0010] These and other objects and advantages of the invention are achieved by providing a roll-out waste bin of the type characterized by having a receptacle mounted on wheels, a hinged lid enclosing an open top of the receptacle, a handle, a downward lip along a front top rim of the receptacle and a vertically spaced retention bar for being grasped by an external lifter for elevating and emptying the contents from the receptacle. The waste bin also includes first and second laterally spaced-part vertical walls extending outwardly and forwardly from a forward side of the receptacle and positioned to form respective first and second retention bar housings. [0011] A first aperture is formed in the first vertical wall and a second aperture is formed in the second vertical wall for receiving the retention bar. The first and second apertures have diameters sufficiently large to permit free rotation of the retention bar in the first and second apertures. A rib is positioned in the first retention bar housing and adapted to abut a first end of the retention bar extending into the first retention bar housing to prevent movement of the retention bar into the first retention bar housing beyond a predetermined point. [0012] A lock cooperates with the exterior of the retention bar between the first and second retention bar housings, and is adapted to engage the second retention bar housing to restrain side-to-side movement of the retention bar out of the first and second apertures. [0013] In accordance with one embodiment of the invention, the rib engages an end face of the retention bar. [0014] In accordance with one embodiment of the invention, the retention bar is cylindrical and the first and second apertures are circular. [0015] In accordance with one embodiment of the invention, the first and second retention bar housings each comprise one vertical wall, one front closeout wall and two external walls of the waste bin receptacle. [0016] In accordance with one embodiment of the invention, the lock comprises a protrusion on an axially-extending surface of the retention bar exterior to both of the first and second vertical walls in order to prevent passage of the retention bar further through the second aperture into the second retention bar housing. [0017] In accordance with one embodiment of the invention, the protrusion comprises a rivet positioned in a hole in the retention bar. [0018] In accordance with one embodiment of the invention, the two external walls of the first and second retention bar housings define a recess having a depth equal to the depth of the vertical walls. [0019] In accordance with one embodiment of the invention, the retention bar is longer than the distance between the first and second vertical walls and shorter than the distance between opposed external walls of the waste bin receptacle. [0020] In accordance with one embodiment of the invention, a method of installing a retention bar onto a roll-out waste bin is provided. The waste bin is of the type characterized by having a receptacle mounted on wheels, a hinged lid enclosing an open top of the receptacle, a handle, a downward lip along a front top rim of the receptacle wherein the retention bar is vertically spaced from the lip for being grasped by an external lifter for elevating and emptying the contents from the receptacle. The method includes the steps of providing first and second laterally spaced-part vertical walls extending outwardly and forwardly from a forward side of the receptacle, and positioned to form respective first and second retention bar housings. A first aperture is formed in the first vertical wall and a second aperture is formed in the second vertical wall, each aperture adapted for receiving one end portion of the retention bar. The first and second apertures have diameters sufficiently large to permit free rotation of the retention bar in the first and second apertures. A rib is positioned in the first retention bar housing and is adapted to abut a first end of the retention bar extending into the first retention bar housing to prevent movement of the retention bar into the first retention bar housing beyond a predetermined point. A lock cooperates with the exterior of the retention bar between the first and second retention bar housings, and is adapted to engage the second retention bar housing to restrain side-to-side movement of the retention bar out of the first and second apertures. A retention bar is provided that is longer than the distance between the first and second vertical walls and shorter than the distance between opposed external walls of the waste bin receptacle. The retention bar is inserted into and through the second aperture into the second retention bar housing to a point where the retention bar can be moved into alignment with the first and second apertures. The retention bar is moved out of the second retention bar housing a sufficient distance to cause the retention bar to enter the first aperture and pass into the first retention bar housing and abut the rib with an opposing end portion of the retention bar remaining in the second retention bar housing. A protrusion is applied to the surface of the retention bar at a position where the retention bar is locked against being removed from either the first or second retention bar housing. [0021] According to another embodiment of the invention, the step of applying a protrusion to the surface of the retention bar comprises the step of applying a rivet through a wall of the retention bar. BRIEF DESCRIPTION OF THE DRAWING FIGURES [0022] The present invention is best understood when the following detailed description of the invention is read with reference to the accompanying drawings, in which: [0023] FIG. 1 is a roll-out waste bin according to one prior art design with which the retention bar of the present invention may be utilized; [0024] FIG. 1A is a fragmentary enlarged view of the retention bar area of the waste bin shown in FIG. 1 ; [0025] FIG. 2 is a waste bin of a type with which the retention bar of the present invention may be utilized; [0026] FIG. 2A is a fragmentary enlarged view of the retention bar mechanism shown in FIG. 2 ; [0027] FIG. 3 is a top plan view of the waste bin having a retention bar mechanism according to the prior art design of FIGS. 2 and 2A ; [0028] FIG. 3A is a fragmentary enlarged view of the retention bar mechanism shown in FIG. 3 ; [0029] FIG. 4 is a top plan view of a waste bin having a retention bar mechanism according to one preferred embodiment of the present invention; [0030] FIG. 4A is a fragmentary enlarged view of the novel retention bar mechanism shown in FIG. 4 ; [0031] FIGS. 5-9 are enlarged fragmentary sequential views of a retention bar according to a preferred embodiment of the present invention being inserted into the retention bar housings of a waste bin; [0032] FIG. 10 is a further enlarged fragmentary view of the position of the retention bar shown in FIG. 9 ; and [0033] FIG. 11 is a still further fragmentary view showing a side elevation of the top plan view shown in FIG. 10 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0034] Referring now to the drawings, a roll-out waste bin 10 that includes a prior art retention bar receiving area according to one prior art design is shown in FIGS. 1 and 1A , and includes a waste receptacle 12 mounted on wheels 14 , one shown, and covered by a hinged lid 16 , with handles 18 . [0035] A downwardly-facing lip 19 extends along the front top rim of the waste receptacle 12 and is gripped by the automated lifter in order to lift and dump the contents of the waste bin 10 . A retention bar receiving area 20 is formed of two parallel, vertical walls 22 , 24 that are external to the interior volume receptacle 12 and spaced apart at a distance that is less than the length of the retention bar, not shown. The vertical walls 22 , 24 have respective apertures 26 , 28 through which the retention bar is placed, with enough clearance to allow the retention bar to spin freely. [0036] Another waste bin that includes a prior art retention bar receiving area according to another design is shown at reference numeral 30 in FIGS. 2 , 2 A, 3 and 3 A. The waste bin 30 includes a waste receptacle 32 mounted on wheels 34 , one shown, and covered by a hinged lid 36 , with handles 38 and a downwardly-facing lip 40 , as described above. A retention bar receiving area 50 includes front closeout walls 52 , 54 that connect vertical walls 56 , 58 to the waste bin receptacle 32 , thereby creating two retention bar housings 60 , 62 , see FIG. 3A , each housing 60 , 62 having one vertical wall 56 , 58 , respectively, one front closeout wall 52 , 54 respectively, and two external walls 64 , 66 and 68 , 70 , respectively, of the waste bin receptacle 32 . Vertical walls 56 , 58 include respective opposed retention bar apertures 61 , 63 . [0037] As best shown in FIG. 3A , a pair of ribs 72 , 74 , one residing inside each of the retention bar housings 60 , 62 , respectively, are formed integral to the receptacle 32 and extend from the respective external walls 64 , 68 of the retention bar housings 60 , 62 . These ribs 72 , 74 trap the retention bar 80 after it has been slid into position through the retention bar housing apertures, preventing the retention bar from moving side-to-side enough to be removed. The ribs 72 , 74 are positioned in the retention bar housings 60 , 62 to normally interfere with the retention bar 80 and thereby prevent the retention bar 80 from being pulled free of free of the bin 30 . In order to insert the retention bar 80 , these ribs 72 , 74 have a degree of flexibility, and are typically deflected by the retention bar 80 during insertion sufficiently to allow the retention bar 80 to slide past the ribs 72 , 74 and enter the retention bar housings 60 , 62 , whereupon the ribs 72 , 74 move back into their normal positions that interfere with removal of the retention bar 80 , locking the retention bar 80 into the retention bar housings 60 , 62 . [0038] Referring now to FIGS. 4-9 , top plan views of a roll-out bin 100 is shown. The bin 100 includes features and elements that are the same as the features and elements of bin 30 and as to those features and elements, the same reference numerals are used. As is illustrated in FIGS. 4-9 , the principal difference in the bin 30 and bin 100 is that the rib 72 of the retention bar housing 60 has been omitted in accordance with the novel features described and claimed in this application. [0039] Applicant also notes that the invention of this application is not dependent on the presence of all of the features of the bin 30 . The invention is equally usable with reference to bin 10 illustrated in FIGS. 1 , 1 A, and any other roll-out waste bin having opposed walls into which a retention bar is inserted and retained. [0040] With these explanations in mind, FIGS. 4-9 illustrate sequentially the insertion of a retention bar 102 in accordance with the method of the invention of this application. As shown in FIG. 5 , one end of the retention bar 102 is inserted into the aperture 61 in retention bar housing 60 at an angle necessitated to achieve clearance of the opposing retention bar housing 62 and the vertical wall 58 . In accordance with the particular embodiment shown in FIGS. 4-9 , a hole 104 is formed in the retention bar 102 proximate one end. The end of the retention bar 102 with this hole 104 is inserted first. The hole 104 is positioned on the retention bar 102 in a location whereby it resides outside the vertical wall 56 of the retention housing 62 when insertion of the retention bar 102 is complete. See FIGS. 9-11 . [0041] As shown in FIGS. 6-8 , when the retention bar 102 is fully extended into the retention bar housing 60 , its length is sufficiently short to enable it to clear the vertical wall 58 , as shown in FIG. 7 . In the position shown in FIG. 8 , the retention bar 102 is slid through the aperture 63 in the vertical wall 58 and into the retention bar housing 62 until it is stopped from further insertion by the rib 74 . In this position, shown in FIG. 9 , the hole 104 resides outside the retention bar housing 60 . As shown in FIGS. 10 and 11 , a drive rivet 106 is then inserted into the hole 104 . The head of the rivet 106 extends sufficiently above the axially-extending surface of the retention bar 102 to interfere with and prevent the retention bar 102 from sliding further back into the retention bar housing 60 . This feature in combination with the engagement of the other end of the retention bar 102 with the rib 74 locks the retention bar 102 into the area between the two retention housings 60 , 62 , while still permitting it to rotate as needed. [0042] Alternative devices may be employed to replace the rivet 106 , and may include an end cap, not shown, on the retention bar 102 having an axially-extending protrusion of such proportion that the protrusion can deform under pressure to allow the placement of the retention bar 102 through the aperture 61 and return to its original shape when said pressure is relieved, with its original shape creating interference with the exterior wall 56 of the retention bar housing 60 that opposes the rib 74 . [0043] Another alternative embodiment may be an end cap of the retention bar 102 having multiple protrusions, not shown, of such proportions that the protrusions deform under pressure to allow the placement of the retention bar 102 through the aperture 61 , returning to their original shape when the pressure is relieved, with their original shape creating interference with the exterior wall 56 of the retention bar housing 60 that opposes the rib 74 . [0044] Other possible embodiments, not shown, can include but are not limited to snap-fit type mechanisms, either integral to the retention bar 102 or as part of a secondary component added to the retention bar 102 , such as spring-released buttons or hooks. [0045] A lift mechanism for a roll-out waste bin according to the invention has been described with reference to specific embodiments and examples. Various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation, the invention being defined by the claims.

A roll-out waste bin includes a retention bar that is held in place on the bin by a pair of retention bar housings. A rib in one of the retention bar housings engages one end of the retention bar and a protrusion on the other end of the retention bar and exterior to both of the retention bars housings positions the retention bar.

This is a continuation of application Ser. No. 807,084, filed June 6, 1977 now abandoned. BACKGROUND OF THE INVENTION This invention relates to an electronic musical instrument having a portamento property and capable of continuously varying the tone pitch from a frequency corresponding to the note of a first key to that corresponding to the note of the a second, subsequently operated, key. A typical prior art electronic musical instrument having the portamento property is disclosed in U.S. Pat. No. 3,866,836 issued June 3, 1975. The basic construction of an electronic musical instrument of this type will be described with reference to FIG. 1 of the accompanying drawings. When a key of a keyboard section 11 is depressed there are produced a voltage signal KV (hereinafter termed a pitch voltage ) corresponding to the pitch of the note of the operated key, and a pulse signal KS (hereinafter termed of keying signal) having a width corresponding to a period of time during which the key is depressed. The pitch voltage KV is applied to act as an oscillator driving signal to a voltage controlled type oscillator 17 (hereinafter called VCO) via voltage holding time constant circuit 12 comprising a switching element 13 in the form of a field effect transistor, a variable resistor 14, a capacitor 15 and a portamento property selection switch 16 connected in parallel with the variable resistor 14 for producing a tone source signal. The tone source signal is applied to a voltage controlled filter 18 (hereinafter termed VCF) to form a musical tone by coloring a tone. The tone signal produced by VCF 18 is subjected to the control of a musical tone level that is an envelope in a voltage controlled type variable gain amplifier 19 (hereinafter called VCA), and the output of this VCA is amplified by an amplifier 20 to produce a tone from a loudspeaker 21. The keying signal KS is applied as a driving signal to the voltage holding time constant circuit 12 which is used to hold the pitch voltage KV snd to impart the portamento property, and to control voltage generators 21, 22 and 23 (hereinafter termed CVG). In response to the keying signal KS generated by key, these control voltage generators CVG's generate time-variable control voltage signals controlled by a variety of parameters which are set in a parameter control voltage generator 24, and these control voltage signals are applied to VCO 17, VCF 18 and VCA 19 respectively. In the VCO 17, the oscillation frequency is finely varied in accordance with the control voltage signal from CVG 21, while in VCF 18, the cut-off frequency is varied to form a musical tone signal resembling a natural musical tone. The VCA 19 operates to form a musical tone envelope in accordance with a control wave signal. During the normal play the selection switch 16 of the voltage holding time constant circuit 12 is closed so as to apply the pitch voltage KV generated by a depressed key directly to VCO 17 via the selection switch 16 and to store the tone voltage KV in capacitor 15. The purpose of capacitor 15 is to hold the pitch voltage KV for obtaining a sustained tone after release of the key while the purpose of the switching element 13 is to prevent the discharge of the voltage held by the capacitor 15. In an electronic musical instrument having the construction described above, where it is desired to provide a portamento property, the portamento property selection switch 16 is opened to charge the pitch voltage KV in capacitor 15 via variable resistor 14 so that the voltage applied to VCO 17 varies with a time constant determined by the variable resistor 14 and capacitor 15. A pitch voltage KV 1 corresponding to a previously depressed key (the first key) is stored in the capacitor 15 as shown in FIG. 2 and when a new pitch voltage KV 2 corresponding to a subsequently depressed key (the second key) is generated at time t 1 , the terminal voltage of the capacitor 15 increases logarithmically as shown by a solid line in FIG. 2 at a speed corresponding to the time constant determined by the variable resistor 14 and capacitor 15. As a consequence, the oscillation frequency of VCO 17 varies continuously as shown by the solid line in FIG. 2, whereby the pitch varies continuously from the pitch of the first key to that of the second key. When the audiences hear such musical sound having the portamento property, since the pitch frequency of the tone source signal produced by the VCO 17 varies rapidly and then slowly as shown by the solid line curve shown in FIG. 2, it varies differently from the actual pitch variation in the natural portamento shown by dotted lines in FIG. 2 thus giving an unnatural feeling to the audiences. SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide an improved electronic musical instrument capable of providing a portamento property whose pitch frequency varies like a natural sound. According to this invention, when supplying a pitch voltage corresponding to a second key to a capacitor holding a pitch voltage corresponding to a first key, the charging and discharging currents of the capacitor are such that the current that charges the capacitor according to the difference between the two pitch voltages varies exponentially thereby causing the terminal voltage of the capacitor which drives a voltage controlled oscillator to vary exponentially. For the purpose of exponentially varying the capacitor terminal voltage a mutual conductance converter is connected between the capacitor and the keyboard section and a detector is provided for detecting a control signal corresponding to the capacitor terminal voltage so as to control the output voltage of the mutual conductance converter by the control signal. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings FIG. 1 is block diagram showing the basic construction of a prior art electronic musical instrument having a portamento property; FIG. 2 is a graph showing the pitch voltage variation produced by the capacitor shown in FIG. 1 and such variation in the natural portamento; FIG. 3 is a connection diagram showing one embodiment of the novel electronic musical instrument of this invention and having a portamento property; FIG. 4 is a connection diagram showing one example of the current controlled mutual conductance converter and of the current controlling circuit shown in FIG. 3; FIG. 5 is a graph showing a collector current base-emitter voltage of a transistor useful to explain the operation of the converter; FIGS. 6A and 6B are waveforms showing the input voltage to the converter and the terminal voltage of the capacitor shown in FIG. 3 where the pitch voltage of the second key is higher than that of the first key; FIGS. 7A and 7B are waveforms showing the converter input voltage and the capacitor terminal voltage where the pitch voltage of the second key is lower than that of the first key; FIG. 8 is a connection diagram showing a modified embodiment of this invention; and FIG. 9 is a connection diagram showing another example of the current controlling circuit shown in FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the electronic musical instrument of the invention having a portamento property shown in FIG. 3 comprises a comparator 32 which compares the pitch voltage KV sent from the keyboard section 11 shown in FIG. 1 with the output voltage of a source follower amplifier 33 having a high input impedance and a low output impedance and also serving as a buffer circuit (described below) so that the comparator 32 produces a zero output when the pitch voltage KV coincides with the output voltage of the source follower amplifier 33. The pitch voltage KV is applied to the positive input terminal 32 a of the comparator 32, whereas the output voltage V 0 from the buffer circuit 33 is applied to the negative terminal (-). The comparator 32 is also supplied with source voltages +V s and -V s . A resistance voltage divider 34 for dividing the output voltage of the comparator 32 is constituted by resistors 34 a and 34 b which are connected in series between the output terminal of the comparator 32 and ground potential. A current controlled mutual conductance converter 36 is provided for controlling the output voltage from the voltage divider 34 in accordance with a control current i produced by a current controlling circuit 35. The positive input terminal (+) of the converter 36 is connected to the junction between resistors 34 a and 34 b of the voltage divider 34, while the negative input terminal (-) is grounded via a resistor 36 a . Source voltages +V s and -V s are also applied to the current controlled mutual conductance converter 36. The output terminal of this converter 36 is connected to one terminal of a capacitor 37, the other terminal of which is grounded. The source follower amplifier 33 adapted to amplify the terminal voltages of capacitor 37 includes a field effect transistor 33 a of a high input impedance having a drain electrode connected to the voltage source +V s , and a source electrode connected to the voltage source -V s via a load resistor 33 b . The output terminal 33 c connected to the source electrode is connected to the VCO 17 shown in FIG. 1. The current controlling circuit 35 for producing the control current i corresponding to the output voltage from the source follower amplifier 33 supplies the control current i to the control terminal 36 b of the current controlled mutual conductance converter 36. The current controlling circuit 35 includes a transistor 35 a having an emitter electrode connected to the output terminal 33 c of the source follower amplifier 33 via a variable resistor 35 b , a collector electrode connected to the control terminal 36 b of the current controlled conductance converter 36 and a base electrode connected to the voltage source -V s via a resistor 35 c and to the ground through a diode 35 d . The variable resistor 35 b varies the control current i for the purpose hereinafter described. FIG. 4 shows one example of the current control circuit 35 and the current controlled mutual conductance converter 36 described above. As shown the converter 36 comprises a pair of NPN type transistors 36 c and 36 d with their emitter electrodes connected together so as to constitute a differential amplifier. The base electrode of the transistor 36 c is connected to receive the output voltage V i of the voltage divider 34 via positive input terminal (+). The base electrode of transistor 36 d is connected to one terminal of a resistor 36 a via the negative input terminal (-). The commonly connected emitter electrodes of transistors 36 c and 36 d are connected to the collector electrode of a transistor 36 1 which constitutes a current mirror circuit together with a transistor 36 m . The collector electrode of the transistor 36 m is supplied with the output current of the current controlling circuit 35, that is the collector current of the transistor 35 a via control terminal 36 b which acts as the control current i for the converter 36. Since a fixed bias voltage is applied to the base electrode of transistor 35 a , the current i varies in accordance with the input to the current controlling circuit 35, that is the output V 0 of the source follower amplifier 33. Accordingly, a portion of the control current i proportional to the input V 0 to the current controlling circuit 35 flows through the collector electrodes of transistors 36 c and 36 d as the collector currents I c1 and I c2 . The same current as the collector current I c1 of the transistor 36 c flows to the collector electrode of a transistor 36 f through PNP transistors 36 e and 36 f and NPN transistors 36 g and 36 h which constitute a current mirror. Similarly, the same current as the collector current I c2 of the transistor 36 d flows to the collector electrode of a transistor 36 j through PNP transistors 36 i and 36 j which constitute a current mirror. The output terminal 36 k of the converter 36 is connected to the juncture between the collector electrodes of transistors 36 f and 36 g . Consequently, the output current I derived out from the output terminal 36 k is expressed by an equation I=I c1 -I c2 . When an input V i is not supplied to the base electrode of the transistor 36 c via the positive input terminal (+) I c1 =I c2 =i/2 so that the output current I is zero. The collector current i/2 at this time represents the operating point of the converter 36 and as the input V i is applied the collector current I c1 varies about the operating point and twice of the variation is taken out as the output current I of the converter 36. In this manner, the mutual conductance gm of the converter 36 is determined by the collector currents of transistors 36 c and 36 d . More particularly, the relationship between the collector current I c1 of transistor 36 c and the base-emitter voltage V BE thereof represents the forward characteristic of a diode as shown in FIG. 5. For this reason, the collector current I c1 of transistor 36 c is expressed by an equation I.sub.c1 =I.sub.0 (exp HV.sub.BE -l) 1 where I 0 represents the saturation current, and H a constant. Since the mutual conductance gm is equal to current I c1 differentiated with respect to the voltage V BE , ##EQU1## Since exp HV BE >>1, the mutual conductance gm can be expressed as follows because it is substantially proportional to the collector current I c1 which in turn is proportional to i/2 and because i/2 is proportional to the control voltage V 0 of the current controlling circuit; gmαI C1 αi/2>V 0 . Thus the mutual conductance can be variably controlled by the control voltage V 0 . The electronic musical instrument having the portamento property and constructed as above described operates as follows. Under a condition wherein capacitor 37 is charged to a voltage V and holds voltage V 0 at the output terminal 33 c , when a pitch voltage KV is impressed upon the input terminal 32 a of the comparator 32 it produces the difference between the pitch voltage KV and the capacitor voltage V, which is applied to the voltage divider 34. Denoting the partial voltage produced by the voltage divider 34 by V i and the control current produced by the current controlling circuit 35 by i, the output current I produced by the current controlled mutual conductance converter 36 is expressed by the following equation I=B.V.sub.i .i 3 where B represents a constant. The control current i produced by the current controlling circuit 35 is expressed by the following equation. ##EQU2## where R represents the resistance value of the variable resistor 35 b , and V O =V-ΔV represents the output voltage of the source follower amplifier 33, V the charged voltage of capacitor 15, ΔV the gate-source voltage V GS of the transistor 33 a and K' and A' constants. By substituting equation 4 into equation 3, the equation of the output current I is modified as follows. I=B.V.sub.i.(K'V-A')=K"V-A" 5 where K" and A" represent constants. The terminal voltage V of the capacitor 37 is expressed as follows. V=1/c∫I dt 6 where C represents the capacitance of the capacitor 37. By differentiating the both sides of equation 6, we obtain ##EQU3## Substituting equation 5 into equation 7 ##EQU4## where K and A represent constants. By modifying this equation, we obtain ##EQU5## By solving this differential equation, we obtain ##EQU6## where F represents a constant. As above described, according to this invention, the terminal voltage V of capacitor 37 is amplified by the source follower amplifier 33 having a gain G=1, the output voltage V 0 at the output terminal 33 c of the amplifier is converted into a control current i having a magnitude corresponding to the output voltage V 0 by the current controlling circuit 35 and the control current i is used to control the output current I of the current controlled mutual conductance converter 36 so that the charging current (output current I) flowing through the capacitor 37 varies exponentially, that is when the control current i is small the output current I varies in a correspondingly small manner but when the control current i is large, the output current I varies in a correspondingly large manner. Consequently, during the portamento play, while the pitch voltage KV 1 corresponding to the first key is being held by capacitor 37, when the pitch voltage KV 2 corresponding to the second key is applied to the positive input terminal 32 a of the comparator 32 the pitch voltage KV 2 is compared with (KV i -ΔV) by comparator 32 and its differential output is applied to the voltage divider 34 thus producing a partial pulse voltage V i2 as shown in FIG. 6A. This pulse voltage V i2 is applied to the positive input terminal of the current controlled mutual conductance converter 36. At this time, the control current i applied to the control terminal 36 d of the converter 36 from the current controlling circuit 35 is small at first but increases gradually thus controlling the output current I to increase exponentially. Accordingly, the terminal voltage V of capacitor 37 charged with this output current I varies exponentially as shown in FIG. 6B until a steady state is reached at which the voltage V becomes equal to the applied pitch voltage KV 2 . Thereafter, since the output of the comparator 32 is zero, this voltage is held. Accordingly, the source follower amplifier 33 produces an output voltage V 0 having the same waveform as the terminal voltage V of the capacitor 37 at its output terminal 33 c which is supplied to the VCO 17 shown in FIG. 1. Thus, the VCO 17 continuously produces a tone source signal having a frequency corresponding to the variation in the voltage applied thereto thus manifesting the portamento property. According to this invention, as shown in FIG. 6B, the voltage wave supplied to the VCO 17 closely approximates the pitch variation in the natural portamento (see the dotted line characteristics shown in FIG. 2), and the listeners perceive a natural portamento. If the control current i of the current controlling circuit 35 is varied by adjusting the variable resistor 35 b , the variation inclination of the converter output current I is changed accordingly so that the charging speed of the capacitor 37 is controlled. Thus, the tempo of portamento, i.e. the time for continuously changing a tone from one note to the other is controlled. Where the relative magnitude of the pitch voltages produced by the first and second keys is opposite to that described above, the charge accumulated in capacitor 37 at the time of operating the first key discharges through the current controlled mutual conductance converter 36 so that the terminal voltage of the capacitor 37 decreases as above described. More particularly, when the partial voltage shown in FIG. 7A is impressed upon the positive input terminal of the current controlled mutual conductance converter 36, the terminal voltage of the capacitor 37 decreases exponentially as shown in FIG. 7B, thus producing a portamento tone ranging between from a high pitch to a low pitch. FIG. 8 shows a modified embodiment of the electronic musical instrument having a portamento property in which elements corresponding to those shown in FIG. 3 are designated by the same reference characters. This modification differs from that shown in FIG. 3 in the following points, that is the control current i is controlled by the output voltage from the source follower amplifier 33 and a tempo control voltage. In other words, in this embodiment, the tempo of portamento is controlled by voltage in contrast to the embodiment shown in FIG. 3 where it is controlled by current. For this reason, a current controlled mutual conductance converter 40 having the same construction as the converter 36 is included in the current controlling circuit 35. The positive input terminal (+) of the converter 40 is connected to receive a fractional portion of the output voltage V 0 of the source follower amplifier 33 which is produced by a voltage divider 41 comprising resistors 41 a and 41 b , whereas the negative input terminal of the converter 40 is grounded through a resistor 40 a . The control terminal 40 b of the converter 40 is connected to receive the output of the collector electrode of a transistor 42 a . The emitter electrode of this transistor 42 a is connected to receive, via a resistor 42 b , a tempo control voltage generated by a potentiometer (not shown) which is, for example, interlocked with a tempo control member mounted on a control panel of the electronic musical instrument. The base electrode of the transistor 42 a is connected to the voltage source -V s via a resistor 42 c and to ground through a diode 42 d . Consequently, the output current from the current controlling circuit 35 varies in proportion to the tempo control voltage. As can be clearly noted from the foregoing description, the output current from the current controlled mutual conductance converter 40 corresponds to both the output voltage of the source follower amplifier 33 and the tempo control voltage, and this output current is applied to the control terminal 36 b of the current controlled mutual conductance converter 36 to act as the control current i. With the portamento playing instrument described above it is possible to adjust the charging and discharging speed of the capacitor 37 by adjusting the tempo control voltage, thereby to control the tempo of portamento. In the foregoing embodiments the differential output between the pitch voltages of the first and second keys and produced by the comparator 32 is applied to the current controlled mutual conductance converter 36 and when the terminal voltage of the capacitor 37 charged by the output current of the converter 36 becomes equal to an applied pitch voltage the differential output of the comparator 32 becomes zero so that the charging of the capacitor 37 is terminated. It is, however, also possible to interrupt the charging circuit of the capacitor 37 from the converter 36 when the terminal voltage of the capacitor 37 becomes equal to the applied pitch voltage where the pitch voltage is applied directly to the converter 36. The construction of the current controlled mutual conductance converters 36 and 40 is not limited to that shown in FIG. 4 but various other types may be used. For example, a CA3080 type linear integrated circuit made by Radio Corporation of America may be used. The current controlling circuit 35 for producing the control signal applied to the current controlled mutual conductance circuit may be a circuit as shown in FIG. 9. In FIG. 9, the output voltage V 0 of the source follower amplifier circuit 33 is applied to the positive input terminal of an operational amplifier 45 and the output thereof is applied to the base electrode of a NPN transistor 46. The emitter electrode of this transistor is connected to the voltage source -V s via a variable resistor 47 and to the negative input terminal of the amplifier 45. The collector electrode of the transistor 46 is connected to a current mirror circuit (not shown) so that a current corresponding to the collector current in the transistor 46 is applied to the control terminal 36 b of the converter 36. With this arrangement, the voltage to the negative input terminal of the amplifier 45, that is the emitter voltage of the transistor 46 becomes equal to the voltage V 0 . Therefore a current determined by (V 0 -V s )/R 47 flows to the collector electrode of the transistor 46 where R 47 represents a resistance value of the resistor 47. Although the mutual conductance converter 36 has been shown and described as being controlled by an independent current, controlling circuit these elements can be combined into a unitary element. Then the converter may be changed to a voltage controlled type. It is also to be understood that the mutual conductance, converter 36 can be constituted by three terminal active elements, such as a field effect transistor, and a bipolar transistor. In this case, the input terminal of the converter is supplied with the pitch voltage from the keyboard section 11 and one of the inputs is connected to receive a feedback voltage of the output voltage corresponding to the terminal voltage of capacitor 15. As above described according to the portamento playing instrument of this invention the charging current of a capacitor which holds the pitch voltage at the time of playing a portamento is controlled to be varied exponentially and the terminal voltage of the capacitor is used to drive a voltage controlled type oscillator which serves as the tone source circuit as that the frequency of the tone source signal generated by the voltage controlled type oscillator varies exponentially thus closely approximating the frequency variation in the natural portamento. Accordingly it is possible to play the natural portamento by an electronic musical instrument. It should be understood that the invention is not limited to the specific embodiments described above and that many changes and modifications will be obvious to one skilled in the art.

In a electronic musical instrument wherein a portamento is played by supplying the pitch voltage corresponding to a subsequently depressed key to a capacitor holding the pitch voltage corresponding to a previously depressed key, the charge and discharge currents of the capacitor corresponding to the difference between the two pitch voltages are controlled to vary exponentially thus changing exponentially the capacitor terminal voltage. The terminal voltage of the capacitor is applied to drive a voltage controlled oscillator to vary its oscillation frequency. To vary exponentially the terminal voltage of the capacitor, a mutual conductance converter is connected between the capacitor and a keyboard section and the output current from the mutual conductance converter is controlled by a control signal corresponding to the terminal voltage of the capacitor.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority of U.S. Provisional Patent Application No. 61/792,441, filed Mar. 15, 2013, which is hereby incorporated by reference herein in its entirety. TECHNICAL FIELD Implementations of the present disclosure relate to scheduling generally, and more particularly, to filtering lot schedules using a previous schedule. BACKGROUND A difficulty in addressing a manufacturing scheduling problem can be related to the problem size. Typical manufacturing scheduling problems involve stations, tasks to be performed on the stations, and a significantly large number of lots to be processed by the stations. For example, scheduling can depend on a number of tools, a number of lots, a sequential order of operations, constraints, etc. With large scheduling problems, it is generally not possible, nor desirable, to schedule all of the large number of lots. Traditional scheduling systems spend a great amount of time and computing resources in solving a scheduling problem that involves many variables and factors. The difficulty grows very fast as the size of the scheduling problem grows. For this reason, large scheduling problems can be impossible to solve directly. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to “an” or “one” implementation in this disclosure are not necessarily to the same implementation, and such references mean at least one. FIG. 1 is a block diagram illustrating a scheduling system utilizing a lot filtering module; FIG. 2 a block diagram of one implementation of a lot filtering module; FIG. 3 illustrates one implementation of a method for filtering lots using a previous schedule to generate a new schedule; and FIG. 4 illustrates an example computer system. DETAILED DESCRIPTION Implementations of the disclosure are directed to a method and system for filtering lots using a previous schedule to generate a new schedule. A schedule can be a list of tasks that each station (tool) processes. The schedule can include the task start times. Stations, hereinafter also referred to as “tools”, can be certified to run certain tasks. A task can be a task used in the manufacturing of semiconductors and there can be different types of tasks. Examples of tasks can include, and are not limited to, a task to manufacture a product, a task to use a reticle manufacturing tool, a task to inspect a reticle manufacturing tool, a task to process a lot of wafers, etc. A manufacturing facility (e.g., factory) may have a large number of lots to be scheduled and may generate schedules at regular intervals (e.g., every ten minutes, every hour, etc.). A lot can be a group of wafers. Implementations use a previous schedule to identify a portion of the large number of lots to create a smaller, more manageable pool (e.g., list) of lots that can be used to create a new schedule. Implementations greatly reduce the amount of time and resources used to create schedules by using information from a previous schedule. FIG. 1 is a block diagram illustrating a manufacturing system 100 including a fabrication system data source (e.g., manufacturing execution system (MES) 101 ), a dispatcher 103 , and a scheduling system 105 communicating, for example, via a network 120 . The network 120 can be a local area network (LAN), a wireless network, a mobile communications network, a wide area network (WAN), such as the Internet, or similar communication system. In one implementation, the scheduling system 105 includes a lot filtering module 107 . In another implementation, the scheduling system 105 communicates with an external lot filtering module 107 , for example, via the network 120 . The MES 101 , dispatcher 103 , scheduling system 105 , and lot filtering module 107 can be individually hosted by any type of computing device including server computers, gateway computers, desktop computers, laptop computers, tablet computer, notebook computer, PDA (personal digital assistant), mobile communications devices, cell phones, smart phones, hand-held computers, or similar computing device. Alternatively, any combination of MES 101 , dispatcher 103 , scheduling system 105 , and lot filtering module 107 can be hosted on a single computing device including server computers, gateway computers, desktop computers, laptop computers, mobile communications devices, cell phones, smart phones, hand-held computers, or similar computing device. The scheduling system 105 may have a large number of lots to schedule and can generate schedules for processing lots at regular intervals. For example, the scheduling system 105 may generate a schedule every ten minutes, every hour, etc. The lot filtering module 107 can use a previous schedule to create a new schedule (e.g. the new schedule may be generated using a processing device of the scheduling system 105 ). A schedule can include one or more sets of tasks T and a set (e.g., set S) of stations, also known as tools. For example, a schedule may involve forty to fifty stations and more than two thousand tasks. Each task can be processed on one or more stations. The schedule can include a list of what task should be processed on which tool at what time. The lot filtering module 107 can use information in a previous schedule to determine which of the lots to process for a new schedule and can create the new schedule using the selected lots. The new schedule can include the lots to be used for the tasks for the tools. In one implementation, the scheduling system 105 is coupled to a factory system data source (e.g., MES 101 , ERP) to receive lot data and equipment status data. In one implementation, the scheduling system 105 provides the entire schedule (e.g., new schedule) to a dispatcher 103 . The dispatcher 103 can be integrated through the MES 101 to dispatch, for example, wafer lots accordingly. FIG. 2 is a block diagram of one implementation of a lot filtering module 200 . In one implementation, the lot filtering module 200 can be the same as the lot filtering module 107 of FIG. 1 . The lot filtering module 200 can include a schedule validation sub-module 203 , a lot selection sub-module 205 , an analysis sub-module 210 , a schedule creator sub-module 215 , and a user interface (UI) generator sub-module 225 . The lot filtering module 200 can be coupled to one or more data stores 250 . The data store 250 can be a persistent storage unit. A persistent storage unit can be a local storage unit or a remote storage unit. Persistent storage units can be a magnetic storage unit, optical storage unit, solid state storage unit, electronic storage unit (main memory) or similar storage unit. Persistent storage units can be a monolithic device or a distributed set of devices. A “set”, as used herein, refers to any positive whole number of items. The data store 250 can store state data 251 and scheduling data 253 . The state data 251 can describe the current state of the manufacturing facility. Examples of state data 251 can include, and are not limited to, the lots that are available as WIP (work in progress), available tools (e.g., tools not under maintenance), tool identifiers, tool status (e.g., idle, active, etc.), start and end times for tools that are processing, previous tool setups, next tool setups, secondary resource (e.g., reticle) availability, lots that are on hold, lots that are available, lots that are active, lots that are reserved, the priority level for the lots, due dates related to the lots, the lots that have run with a previous schedule, current tool setups, object functions for the lots, objective function weights for lots, reticle transport costs, lower objective function station costs, reticles that do not need inspection, etc. The scheduling data 253 can include previous schedules and information relating to the lots and tools used for the previous schedules. The scheduling data 253 can define tasks to be performed and a set of stations (tools) for performing the tasks. The scheduling data 253 can also describe whether a task can be processed on one or more stations (tools) and can identify one or more stations for performing the task. The scheduling data 253 can include the number stations, station data (e.g., status) describing specific stations, weight type, weight values, etc. The weight types and weight values can be for stations and/or tasks. The schedule validation sub-module 203 can select a previous schedule from the scheduling data 251 and can remove any invalidity in the previous schedule. An invalidity is an element of the previous schedule that would not be valid based on the current state of the manufacturing facility. For example, the state data 251 may indicate that Lot-384782 is on hold and the schedule validation sub-module 203 can remove Lot-384782 from the previous schedule if Lot-384782 is in the previous schedule. One implementation of removing invalidities is described in greater detail below in conjunction with FIG. 3 . The lot selection sub-module 205 can selects lots to be scheduled for a new schedule and can create a lot pool 255 (e.g., list) of lots that are to be used in the new schedule. The lot pool 255 (hereinafter also referred to as a “pool”) can be stored in the data store 250 . The lot selection sub-module 205 use configuration data 259 that is stored in the data store 250 to determine which lots to add to the pool 255 . The configuration data 259 can include selection criteria that may specify that the lot selection sub-module 205 should select high priority lots, lots that can be assigned to any tool idle times in the previous schedule, lots that can satisfy performance indicator criteria (e.g., move targets), and lots to ensure that there is a sufficient number of lots to satisfy the work capacity of each tool. The configuration data 259 can be pre-defined and/or user (e.g., system engineer, industrial engineer, process engineer, system administrator, etc.) defined. The user interface generator sub-module 225 can generate a user interface 202 that can receive user input for configuration data 259 , state data 251 , scheduling data 253 . In on implementation, the configuration data 259 , state data 251 , scheduling data 253 or a portion of the configuration data 259 , state data 251 , and scheduling data 253 is provided by a system in the manufacturing facility. The lot selection sub-module 205 can use the state data 251 to determine which lots to add to the pool 255 . For example, the lot selection sub-module 205 can determine which lots are the high-priority lots and can add the high-priority lots to the pool 255 . One implementation for selecting lots to add to the pool is described in greater detail below in conjunction with FIG. 3 . The lot selection sub-module 205 can select lots that satisfy selection criteria, such as, lots that can be assigned to tool idle time periods, lots that satisfy performance indicators (e.g., move targets), lots that satisfy tool work capacity, etc. The analysis sub-module 210 can perform analyses that can be used to determine whether the current lots in the pool 255 satisfy selection criteria in the configuration data 259 . For example, the analysis sub-module 210 can identify tool idle time periods in the previous schedule and determine which of the tool idle time periods to ignore. In another example, the analysis sub-module 210 can determine which lots satisfy performance indicators (e.g., move targets) and which lots that satisfy tool work capacity, etc. The analysis sub-module 210 can determine whether the lots in the current pool 255 satisfy the selection criteria or whether lots that are not in the current pool 255 satisfy the selection criteria. The analysis sub-module 210 can use the stat data 251 and scheduling data 253 to perform the analyses. The schedule creator sub-module 215 can create a new schedule 257 using the lots in the lot pool 255 . The new schedule 215 can include the lots from the pool 255 to be used for the tasks for the tools. The schedule creator sub-module 215 can create a new schedule for each tool, a new schedule for more than one tool, etc. The new schedule 257 can include a list of what task should be processed on which tool at what time, and can assign a lot from the pool 255 to a corresponding task/tool. The schedules 257 can be stored in the data store. The lot filtering module 200 can send a schedule 257 to a dispatcher system, a corresponding tool, etc. FIG. 3 is a flow diagram of an implementation of a method 300 for creating a new schedule using a previous schedule. Method 300 can be performed by processing logic that can comprise hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (e.g., instructions run on a processing device), or a combination thereof. In one implementation, method 300 is performed by the lot filtering module 107 hosted by a computing device of FIG. 1 . The manufacturing facility may have a large number of lots to be scheduled. The lot filtering module can use information in a previous schedule to identify a subset of the lots to use in a new schedule. At block 301 , the server identifies a previous schedule. In another implementation, the previous schedule is a schedule that was executed. In one implementation, the previous schedule is an immediately preceding schedule that was executed. At block 303 , the server removes invalidities in the previous schedule. An invalidity is an element of the previous schedule that would not be valid based on the current state of the manufacturing facility. The server can remove the lots from the previous schedule that are not valid based on the current state of the manufacturing facility. The server can use state data that is stored in a data store that is coupled to the lot filtering module. For example, some lots that were used to run the previous schedule may no longer be WIP (work in progress), and the server can remove the lots from the previous schedule. Other examples can include, and are not limited to, the server removing lots that no longer have a valid tool that can process the lots, removing lots that require a secondary resource (e.g., reticle) that is no longer available, removing any other lots that can no longer be scheduled (e.g., lots that are on hold), etc. At block 305 , the server generates a pool (e.g., list) of lots to be scheduled for a new schedule. The pool is a subset of the large number of lots at the manufacturing facility. For example, there may be one thousand lots and the server can generate a pool of lots, which is a subset of larger set of lots. The server can evaluate lots in the larger set of lots and add the high-priority lots to the pool. In one implementation, a scheduling system can determine the high-priority lots. In one implementation, the server can access lot data that is stored in a data store that is coupled to the server that describes the priority for the lots. The lot data can be pre-defined and/or user (e.g., system engineer, process engineer, industrial engineer, system administrator, etc.) defined. The lot data may be generated by another system, such as another scheduling sub-system. A schedule (e.g., previous schedule, new schedule) can have a scheduling interval. The scheduling interval can define work capacity for each tool by time. For example, a schedule may have a scheduling interval of six hours' capacity of work for each tool. The server can evaluate lots in the larger set of lots and add the lots with due dates within scheduling interval of the new schedule to the pool. The server can add the lots that ran in the previous schedule's scheduling interval to the pool. In another example, the server can add the lots that are active and the lots that are on reserve to the pool. At block 307 , the server identifies one or more tool idle time period in the previous schedule and determines whether any of the lots in the pool can be assigned to the tool idle time intervals. A schedule can include periods of time. The periods may or may not be assigned to a lot. For example, there may be a period where the tool is idle (e.g., the tool is not performing any work on a lot). For example, a tool may not be assigned any work at 10:00 am. The server can analyze the previous schedule to identify one or more tool idle time periods in the previous schedule. The server may filter out any tool idle time periods that may be short, such that a lot cannot be worked on during the short period of time. The server can use configuration data that is stored in a data store to determine a threshold to use to filter out short tool idle time periods. For example, a period may be a short amount of time that may be for setup changes and may not be used for work on a lot, and the server can ignore the tool idle time periods that are used for setup changes. At block 309 , the server determines whether any of the lots in the pool can be assigned to any of the tool idle time periods. The server can iterate over lots in the pool and if any of the lots in the pool were not in the previous schedule and could satisfy a tool idle time period, the server marks the corresponding tool idle time period as partially or fully satisfied by that lot at block 315 . An example of a lot in the pool that may satisfy the tool idle time is that the lot can use the current setup of the tool. If none of the lots in the pool can be assigned to the tool idle time periods (block 309 ), the server determines whether any of other lots, which are not in the pool, can be assigned to the tool idle time periods at block 311 . The server can use selection criteria to determine which of the lots satisfy the tool idle time periods. The selection criteria can be stored in the data store. The server receives input data. The input can include the current lots in the pool. The input can include parameters to tool idle time periods, such as, and not limited to, station, start and end times, previous reticle(s) used by the lots before the tool idle time period, the next reticle(s) used by the lots before the tool idle time period, reticle(s) on the tool at the start of the interval, etc. The server can select one or more lots using criteria in a pre-defined order and/or user (e.g., system engineer, process engineer, industrial engineer, system administrator, etc.) defined order. Examples of criteria can include, and are not limited, to prefer lots that are part of an unsatisfied move target, prefer lots with a higher objective function weight, prefer lots that use a reticle that is on a tool where the lot step can run, prefer lots that use a setup that is already used on the station where the lot can run, prefer lots in current WIP (work in progress) over predicted lot steps. The server may not prefer lots that were scheduled in the previous schedule, but that started after the end of the previous scheduling interval. For a tool idle time analysis, the selection criteria can include and/or also include, for example, and not limited to, prefer lots with a lower objective function station cost for the station associated with the tool idle time, prefer lots that use the previous or next reticle, prefer lots that use the previous or next setup, prefer lots that use a reticle on the tool, prefer lots whose reticle transport costs are lower, prefer lots whose reticle does not need inspection, do not select a predicted lot that arrives after the start of the interval, etc. A predicted lot has a prediction time for when the lot may be available. For example, a schedule may start at 9:00 am and Lot-A may be processing on Tool-A until 11:00 am. Lot-A's predicted availability for processing on another tool is 11:00 am. Lot-A is a predicted lot. For tool idle time analysis, the server may not assign Lot-A to fill the tool idle time at 9:00 am because Lot-A is not available until 11:00 am. In one implementation some of the criteria are not applied. The server can iterate over the tool idle time periods and if any of the lots satisfy the tool idle time periods (block 311 ), the server adds new lots that satisfy any of the tool idle time periods to the pool at block 313 . At block 315 , the server marks the corresponding tool idle time period as partially or fully satisfied by that lot at block 315 . At block 317 , the server identifies one or more performance indicators. The performance indicators can include one or more criteria to meet. An example of performance indicator can include, and is not limited to, a move target. A move target may be a goal. The goal may be a business-oriented goal. For example, the move target may be to process a certain number of lots of a certain type during the scheduling interval. The performance indicator can be stored as part of configuration data in the data store. At block 319 , the server determines whether the lots in the pool satisfy the performance indicator criteria. If not, the server determines if there are any of other lots, which are not in the pool, that can be assigned to the tool idle time periods at block 321 . The server can use selection criteria to determine which of the lots satisfy the performance indicator criteria. If the server identifies other lots that satisfy the performance indicator criteria (block 321 ), the server adds the other lots to the pool at block 323 . At block 325 , the server determines the amount of work to be performed by the tools for the new schedule that is to be generated. The server can use Equation 1 below to calculate the approximate amount of work that each tool is capable of performing. Suppose lots L, where i=1 . . . N can run on station S and that L, requires T, seconds of capacity on S and can run on n, total stations. Then the approximate amount of work for station S is W ⁡ ( S ) = ∑ i = 1 N ⁢ ⁢ T n i Equation ⁢ ⁢ 1 At block 327 , the server determines whether the lots in the pool can satisfy the capacity of work for each tool. The server can determine whether are a sufficient number of lots in the pool such that each station satisfies W ( S )≧ pSI   Equation 2 where SI is the duration of the scheduling interval. In one implementation, the parameter p=1.15. The parameter p may be configurable a configurable value. The parameter p may be pre-defined and/or user (e.g., system engineer, industrial engineer, process engineer, system administrator, etc.) defined. The parameter p represents a buffer to schedule more lots than are strictly necessary in order to help ensure that all stations have enough work. If there is not a sufficient number of lots in the pool (block 327 ), the server can add lots, which are not currently in the pool, to the pool until each station satisfies Equation 2 above at block 329 . Thus, the quantity pSI may serve as a threshold capacity, which may serve as an indicator that additional lots may be added if the computed work capacity for the tool is below the threshold capacity. The server can use selection criteria to determine which of the lots to add to the pool. At block 331 , the server generates a new schedule using the lots in the pool. The pool has a subset of the larger number of lots in the manufacturing facility. For example, there may be one thousand lots in the manufacturing facility that can be schedule and the pool may have four hundred lots of the one thousand lots. The schedules can be stored in the data store. The server can send a schedule to a dispatcher system, a corresponding tool, etc. FIG. 4 is a block diagram illustrating an example computing device 400 . In one implementation, the computing device corresponds to a computing device hosting a scheduling lot filtering module 107 of FIG. 1 . The computing device 400 includes a set of instructions for causing the machine to perform any one or more of the methodologies discussed herein. In alternative implementations, the machine may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. The machine may operate in the capacity of a server machine in client-server network environment. The machine may be a personal computer (PC), a set-top box (STB), a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. The exemplary computer device 400 includes a processing system (processing device) 402 , a main memory 404 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), etc.), a static memory 406 (e.g., flash memory, static random access memory (SRAM), etc.), and a data storage device 418 , which communicate with each other via a bus 408 . Processing device 402 represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processing device 402 may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, or a processor implementing other instruction sets or processors implementing a combination of instruction sets. The processing device 402 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. The processing device 402 is configured to execute the scheduling problem splitter module 470 for performing the operations and steps discussed herein. The computing device 400 may further include a network interface device 408 . The computing device 400 also may include a video display unit 410 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 412 (e.g., a keyboard), a cursor control device 414 (e.g., a mouse), and a signal generation device 416 (e.g., a speaker). The data storage device 418 may include a computer-readable storage medium 428 on which is stored one or more sets of instructions (instructions of scheduling problem splitter module 470 ) embodying any one or more of the methodologies or functions described herein. The scheduling problem splitter module 470 may also reside, completely or at least partially, within the main memory 404 and/or within the processing device 402 during execution thereof by the computing device 400 , the main memory 404 and the processing device 402 also constituting computer-readable media. The scheduling problem splitter module 470 may further be transmitted or received over a network 420 via the network interface device 408 . While the computer-readable storage medium 428 is shown in an example implementation to be a single medium, the term “computer-readable storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “computer-readable storage medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present disclosure. The term “computer-readable storage medium” shall accordingly be taken to include, but not be limited to, transitory computer-readable storage media, including, but not limited to, propagating electrical or electromagnetic signals, or may be non-transitory computer-readable storage media including, but not limited to, volatile and non-volatile computer memory or storage devices such as a hard disk, solid-state memory, optical media, magnetic media, floppy disk, USB drive, DVD, CD, media cards, register memory, processor caches, random access memory (RAM), etc. In the above description, numerous details are set forth. It will be apparent, however, to one of ordinary skill in the art having the benefit of this disclosure, that implementations of the disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the description. Some portions of the detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as “receiving,” “constructing,” “cutting,” “identifying,” “creating,” “generating,” “assigning,” “sending,” or the like, refer to the actions and processes of a computing device, or similar electronic computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage devices. Implementations of the disclosure also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other implementations will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Methods and systems are provided for filtering lot schedules of a manufacturing facility. A first schedule is identified, in which the first schedule is a previously executed schedule. A processing device generates a pool of lots to be scheduled using information from the first schedule, in which the pool of lots is a subset of a plurality of lots associated with the first schedule. The processing device generates a second schedule using the pool of lots.

BACKGROUND OF THE INVENTION This invention relates to materials handling equipment, and particularly to apparatus for transporting bulk material in which receptacles mounted between two traction members receive the material to be transported and discharge the received material by gravity when the traction members travel over respective guide wheels. The invention will be described in its more specific application to a bucket elevator of the type employed for recovering bulk material from the hold of a ship, but other applications of the invention will readly suggest themselves to those skilled in the art. In the type of elevator chosen for illustrating the invention, approximately cup-shaped receptacles or buckets are mounted in spaced relationship between two traction members, such as cables, chains, or belts which are trained over a pair of upper guide wheels and a pair of lower guide wheels in respective closed loops. The material scooped up by the buckets during and after travel over the lower guide wheels is discharged from the buckets by gravity as they travel over the upper guide wheels. The discharged material is collected and further conveyed away from the elevator. The discharged material must be caught in the zone between the loops of the traction members and taken laterally out of the zone. Because the spokes of conventional guide wheels restrict the location of the necessary chute or the like, some of the height gained by the transported material on the elevator is again lost when the material is dropped on a chute mounted below the upper guide wheels. SUMMARY OF THE INVENTION It is a primary object of this invention to improve the known elevator arrangement in such a manner that the vertical displacement of the transported material brought about by the elevator is more fully utilized. It has been found that spokes or the like on one of the upper guide wheels of an elevator of the type described can be avoided by supporting and/or driving the one guide wheel by means of at least one roller mounted on the supporting structure in a free space about the axis of rotation of the guide wheel which is bounded in a radially outward direction by the rim of the wheel, the roller making rolling, pressure transmitting contact with the wheel rim. DETAILED DESCRIPTION Other features, additional objects, and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understood by reference to the following detailed description of preferred embodiments when considered in connection with the appended drawing in which: FIG. 1 shows a bucket elevator of the invention in fragmentary front elevation; FIG. 2 illustrates the apparatus of FIG. 1 in side elevation; and FIG. 3 shows a modified detail in the apparatus of FIG. 1 in a corresponding view on a larger scale. Referring initially to FIGS. 1 and 2, there is seen only as much of a traveling bucket elevator as is needed for an understanding of the invention. The supporting structure of the elevator includes a gantry traveling along a pier to which ships are moored. Only the boom 8 of the gantry is partly seen in the drawing. Its free end may be located above the open hatch of a ship to be unloaded, and an arm 9 suspended from the boom by means of pivots 10 may be lowered into the hold of the ship and swung about the pivots 10 by means of a hydraulic jack 11 hingedly fastened to the boom 8 by a pivot pin 12. The arm 9 is a flat skeleton frame from whose lower, free end two wheel forks 13, 17 depend on respective hydraulic jacks 14, 18. Circumferentially grooved lower guide wheels 4, 6 are mounted in the forks 13, 17 for normal rotation about a common axis, but may be shifted vertically relative to each other by the jacks 14, 18. The wheels 4, 6 are held by respective cables 2 in rolling, abutting engagement with guide rollers 16 mounted on the associated forks 13, 17 by means of radial arms 15. The rollers engage the circular, internal rim face of each wheel 4, 6 which bounds a free space about the wheel axis. The cables are trained in closed, parallel, axially spaced loops over the lower guide wheels 4, 6 and two upper guide wheels 5, 7 and carry therebetween elevator buckets 1. The wheels 5, 7 have circular rims which bound free spaces about the common axis of wheel rotation. They are supported on respective sets of rollers 21, 22 mounted on the boom 8 in the free spaces within the wheel rims. The wheels are driven by additional sets of rollers 23 engaging the outer circumference of each wheel rim with a contact pressure controlled by pneumatic jacks 24 mounted on a bracket 25 on the boom 8. A hopper 28 mounted axially between the upper guide wheels 5, 7 terminates in a chute which passes obliquely downward through the free space in the center of the wheel 5 to a belt conveyor 29 axially spaced from both wheels 5, 7 in the same direction and leads to the end of the boom 8 omitted from the drawing. In the modified bucket elevator of the invention partly shown in FIG. 3, the outer circumferences of the upper guide wheels are not encumbered by guide or drive rollers. The wheels, as illustrated in FIG. 3 for wheel 7 only, are supported on four rollers 21a mounted in pairs on trucks 26. The trucks are fastened to the boom 8 by arms 27 axially extending into the free space bounded by the rim of the wheel 7 in a radially outward direction and may pivot on bearing 27' about axes parallel to the wheel axis. The trucks 26 with the guide rollers 21a mounted thereon are circumferentially interposed between three similar trucks 26' carrying each a drive motor (not shown) and two rollers 21b driven by the motor. The trucks 26' are spring-mounted on the arms 27 and their motion-transmitting contact pressure against the inner rim of the wheel 7 is maintained and may be controlled by pneumatic jacks 30. The hopper and chute which guide the material dropped from the buckets 1 to a conveyor 29 has been omitted from FIG. 3 in order not to crowd the drawing. As is evident from the converging straight loop portions of the cable 2 shown in FIG. 3, the lower guide wheels, not themselves seen in FIG. 3, are smaller in diameter than the top guide wheel 7. The structure omitted from the showing of FIG. 3 may otherwise be identical with what has been illustrated more fully in FIGS. 1 and 2. The illustrated friction drives have been found effective in bucket elevators transporting heavy material at high speed. However, slippage between the driven rollers and the rims of the guide wheels may be prevented entirely by providing meshing gear teeth on the engaged surfaces in an obvious manner. Necessary tension in the cables 2 is maintained by the jacks 14, 18, and the axes of the wheels 4, 6 may be offset from each other to some extent without affecting the operation of the elevator if necessary to compensate for different stretching of the two cables 2. All four guide wheels of the illustrated bucket elevators are free from spokes and supported and driven by rim-engaging rollers mounted on the supporting structure. Such as arrangement is preferred because it simplifies maintenance operations. However, one of the most important objects of this invention is achieved if only the wheel 5 is free from spokes or other rotating wheel elements encumbering the space outwardly bounded by the wheel rim. The number and location of the driven rollers may be chosen to suit specific operating conditions. When the material to be transported is relatively light, a single drive roller acting on the inner or outer circumference of a single wheel rim may suffice. If at least one wheel has spokes and a central hub, that wheel may be driven by a shaft fastened to the hub in a conventional manner, and the rim-engaging rollers may only transmit the weight of an associated wheel to the supporting structure, no roller being part of the drive mechanism. However, this invention has found its most important application in the removal of heavy bulk material, such as ore, from the hull of freighters, and the illustrated embodiments have proven most advantageous for such application. When both upper guide wheels are of the illustrated type, a belt conveyor may pass through both free spaces within the wheel rims, and only baffles or similar simple devices are needed for guiding the bulk material discharged by gravity through the apertures of the buckets 1 to the conveyor belt. Other changes in the specifically illustrated embodiments of the invention will readily suggest themselves to those skilled in the art. It should be understood, therefore, that the foregoing disclosure relates only to preferred embodiments of the invention, and that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of the disclosure which do not constitute departures from the spirit and scope of the invention set forth in the appended claims.

In a bucket elevator having two traction members guided in parallel loops by upper and lower guide wheels, and buckets spacedly mounted between the traction members, the rim of at least one of the upper guide wheels defines a free space about its axis of rotation, and one or more rollers mounted on the supporting structure in the free space engage the rim for supporting and/or driving the wheel so that the material discharged from the buckets during travel over the upper guide wheels can be conveyed further by a chute extending axially through the one upper guide wheel.

BACKGROUND OF THE INVENTION This invention pertains to and is concerned with a vertical convection heat dissipater tower wherein heat exchange coils filled with refrigerant fluid are disposed within the tower. The exchange coils allow a gradual transfer of heat from the refrigerant fluid to a cooling fluid contained within the tower. The tower of this invention is primarily intended for utilization with commercial and residential air conditioning systems, but also has application in heat pumps. The construction arrangement of the tower utilizes the natural heat transfer principle of convection, and specifically, the phenomenon known as "stacking". DESCRIPTION OF THE PRIOR ART The applicant is unaware of any closely related patents disclosing a vertical convection heat dissipater tower similar to that of the present invention. However, various heat exchangers or chillers have been known for many years. Typically, such exchangers or chillers are mounted horizontally with cooling fluid entering at one side and discharging from the other side. Structurally, the cooling water flows through a jacket which encases numerous tubes. The tubes contain the fluids sought to be cooled. Other embodiments of heat exchangers utilize a continuously wound tubing configuration. In all of the configurations known, no attempt has been made to utilize the "stacking" phenomenon wherein warmer and lighter fluids rise and cooler and heavier fluids sink. Further, the cooling fluids rates through existing exchangers are not known to be adapted or adjusted to reduce mixing or eddy currents. The applicant is unaware of any prior art which insulates any portion of the coils or tubes within any existing exchanger to eliminate reheating of the fluid within the tubes as they exit the exchanger. SUMMARY OF THE INVENTION A cylindrical housing having a top cap and a bottom cap with helically wound heat exchange coils disposed within the housing makes up the primary structural components of the invention. Cooling fluid, such as water, is slowly introduced into the housing tangentially through the bottom cap. Because of the low flow rate and the tangential introduction, cool water tends to remain at the bottom of the tower while warmer water rises to the top of the tower. Convection currents result within the tower because every fluid expands when heated, so that a given quantity of fluid increases in volume, and consequently decreases in density. In the convection current, the lighter fluid is pushed up by the heavier surrounding fluid, just as a block of wood under water is pushed to the surface by surrounding water. Thus, a "stack" or gradually increasing temperature gradient is developed from the bottom of the tower to top of the tower. The "stacking" phenomenon is enhanced as hot refrigerant fluid entering the tower through the top cap from, for example, the condenser unit of the conventional air conditioner, passes through the coils. The hot refrigerant fluid first encounters cooling fluid within the tower having a temperature lower than itself. Thus, a heat exchange occurs. As the refrigerant fluid moves down the tower through the coils, it encounters gradually cooler portions of cooling fluid, causing a continuous heat exchange resulting in a gradual cooling of the refrigerant fluid itself. Upon reaching the bottom of the coil, and at the point of lowest cooling fluid temperature, the refrigerant fluid is also at its lowest temperature. The refrigerant fluid then flows through an insulated, uncoiled portion of the exchange coil, up through the tower, and exits through the top cap at the top of the tower. The insulated portion of the coil reduces the possibility of heat transfer between the refrigerant fluid and the water or cooling fluid as the refrigerant fluid passes through the warmer temperature portions of the tower. To reduce the quantity of cooling fluid or water introduced into the tower, a switching means is connected to the valving to shut off cooling fluid when refrigerant is not flowing through the coils. For example, a solenoid valve may be wired into the condenser circuit of the conventional air conditioning system to open the cooling fluid flow line when the compressor is operating. Alternative embodiments of the invention utilize split-discs to partition the tower into multiple compartments to enhance "stacking" of the temperature gradient. Further embodiments incorporate multiple coil arrangements to increase the heat transfer surface area. Testing has shown that where the tower height to the tower diameter is maintained within certain proportions, maximum heat transfer occurs. It is an object of this invention to lower the refrigerant fluid temperature from the compressor of a typical air conditioning system prior to its passing through the evaporator. This lower temperature results in lower evaporator cooling coil temperatures. Further, the lower temperature reduces compressor head pressure thus reducing compressor amperage. These results combine to reduce overall energy consumption and improve system efficiency. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the invention attached to the side of the conventional air conditioning unit. FIG. 2 is an elevated cross-section of the invention. FIG. 3 is a top view of FIG. 2 with the cap removed. FIG. 4 is a bottom view of FIG. 2. FIG. 5 is an elevated cross-sectional view of an alternative embodiment of the invention. FIG. 6 is a perspective view of a split-disc used in the alternative embodiment of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT For a detailed description of the preferred embodiment, reference is made to the attached several views wherein identical reference characters will be utilized to refer to identical or equivalent components throughout the various views in the following description. Referring now to FIG. 1, the vertical convection heat dissipator tower 10 of this invention includes a cylindrical housing 12 attached vertically by suitable connecting means 14 to a condenser 16 of a conventional air conditioning unit (not shown in detail). The cylindrical housing further includes a top cap 18 and a bottom cap 20 secured to the ends of the housing 12. The tower 10 may be constructed of any suitable material, which may or may not be insulated. The tower 10 and caps 18 and 20 of the preferred embodiment are constructed of polyvinyl chloride tubing to facilitate manufacture, reduce costs, and reduce maintenance. Entering the bottom cap 20 tangentially is the cooling fluid line 22. In the preferred embodiment, the cooling fluid line 22 would be further connected to a convenient low pressure water supply source. Interposed in the cooling fluid line 22 is a flow rate adjustment valve 24 and an automatic flow control valve 26. Both the flow rate adjustment valve 24 and the automatic flow control valve 26 are standard in the industry. In the preferred embodiment, the automatic flow control valve 26 is electrically wired to open when the air conditioner condenser circuit is energized. Flow rate adjustment valve 24 may be sized to accommodate any flow rate to ensure proper operation, but flow rates in the range of one-quarter (1/4) gallon per minute to one-half (1/2) gallon per minute are typical. Bottom cap 20 is further adapted with a drain plug 28 to enable the tower to be completely drained of all cooling fluid. The drain plug 28 may be threaded into the bottom cap 20 using standard size plumbing accessories. The top cap 18 has an opening 34 (see FIG. 3) to receive the refrigerant fluid inlet line 30. In the preferred embodiment, the refrigerant fluid inlet line 30 runs from the outlet side of the condenser 16 in a conventional air conditioning system. Opening 35 in top cap 18 also allows the refrigerant fluid outlet line 32 to pass through the cap 18 on its way to the evaporator portion of a conventional air conditioning system (not shown). A cooling fluid discharge line 29 is connected to an upper portion of the tower 10. The cooling fluid which flows into the housing 12 and is not evaporated flows out through the cooling fluid discharge line 29 to be recycled or discharged. While the preferred embodiment calls for the refrigerant fluid inlet and outlet lines 30 and 32 to pass through openings 34 and 35, respectively, in the top cap 18, refrigerant fluid inlet and outlet lines 30 and 32 could pass through any opening in tower 10 located above the cooling fluid discharge line 29. Viewing FIG. 2, a cross-section of the invention may be seen. Refrigerant fluid inlet line 30 enters the top cap 18 through aperture 34. Refrigerant fluid inlet line 30 in the preferred embodiment is constructed of 3/8" copper line coated with acrylic plastic or chrome plated to protect it from oxidation which reduces heat transfer. Refrigerant fluid inlet line 30 is spirally or helically wound in a relatively tight coil 36 that extends the entire length of the cylindrical housing, 12. In an embodiment utilizing 3/8" copper tubing (thin-walled), the coil is wound to have a 31/2" diameter coil measured from center-to-center of the tubing. At the bottom portion 13 of the cylindrical housing 12, the refrigerant fluid inlet line 30 is twisted by a sharp bend 31 to extend vertically through the center of the coil 36. For the purpose of this description, the refrigerant fluid inlet line 30 is designated from sharp bend 31 as the refrigerant fluid outlet line 32. Refrigerant fluid outlet line 32 is generally insulated from contact with the cooling fluid within the housing 12 by means of an insulating sleeve 38, which extends the length of refrigerant fluid outlet line 32 from near the sharp bend 31 to top portion 11 of the cylindrical housing 12. Refrigerant fluid outlet line 32 exits the housing 12 via an aperture 35 in top cap 18. Refrigerant fluid outlet line 32 then travels, in the preferred embodiment, to the evaporator portion (not shown) of a conventional air conditioning system. Refrigerant fluid outlet line 32 may be totally insulated along its entire length from the tower 10 to its connection to the evaporator portion so as to eliminate reheating of the refrigerant fluid. FIG. 3 is a sectional view of FIG. 2 taken along section line 3--3. Refrigerant fluid inlet line 30 passes through openings 34 in top cap 18 and begins to coil down through housing 12. Only wrap of the coil 36 is shown in FIG. 3. Insulating sleeve 38 is shown encasing refrigerant fluid outlet line 32 as it rises upward through the center of the coil 36. Refrigerant fluid outlet line 32 passes through aperture 35 in top cap 18. FIG. 4 is a bottom view of FIG. 2 with the cooling fluid inlet line 22 connected tangentially to bottom cap 20. During operation, cooling fluid (preferably water) is introduced into the housing 12 at low flow rates of approximately 1/4-1/2 gallon per minute. Having cooling fluid inlet line 22 located tangentially allows the cooling fluid to enter the housing without creating significant eddy currents or causing a significant mixing of the cooling fluid. FIG. 4 further shows the location of the flow rate adjustment valve 24 and the automatic flow control valve 26 along the cooling fluid inlet line 22 flow path. Viewing FIG. 1, during operation of the preferred embodiment, the invention is filled with water by allowing automatic flow control valve 26 to open. Once the housing is filled with water, the automatic flow control valve is switched over to open only when the condenser unit 16 in the air conditioner system is energized. As hot refrigerant fluids pass through refrigerant fluid inlet line 30 and down through the coil 36, heat is transferred to the cooling fluid within the housing 12. Because of the convection current principle, the water at the top of the housing 12 will be warmer than that at the bottom. Thus, a "stacking" or temperature gradient will develop. Small amounts of water are introduced tangentially into the housing 12 to ensure that cooler water is allowed to gradually enter the housing 12. As previously stated, the automatic flow control valve 26 only opens to introduce water when the condenser 16 is operating. As cool water is introduced, warm water at the top of the housing 12 flows through cooling fluid discharge line 29 attached through an opening 27 near the top of the housing 12. The water may be discharged or recycled as desired. FIG. 5 shows a perspective view of another embodiment of the invention. Specifically, the embodiment of FIG. 5 illustrates a double coil arrangement 40 wherein refrigerant fluid inlet line 30 is connected to a "Y" adapter 42 with the first branch 41 connected to a first inlet coil tube 46 and the second branch 43 connected to a second inlet coil tube 48. First inlet coil tube 46 and second inlet coil tube 48 are wound adjacent to one another and extend downwardly through the entire length of the cylindrical housing 12. At the bottom portion of the cylindrical housing 12, first inlet coil tube 46 and second inlet coil tube 48 are twisted by sharp bend 50 and 52, respectively, to extend vertically through the center of the coil arrangement 40. For the purpose of this description, first inlet coil tube 46 and second inlet coil tube 48 are designated from sharp bends 50 and 52, respectively, as first outlet coil tube 54 and second outlet coil tube 56. First and second outlet coil tubes 54 and 56 are generally insulated from contact with the cooling fluid within the cylindrical housing 12 by means of an insulating sleeve 38, which extends the length of first and second outlet coil tubes 54 and 56 from near the sharp bends 50 and 52 to top portion 11 of cylindrical housing 12. First and second outlet coil tubes 54 and 56 are connected to first branch 58 and second branch 60, respectively, of Y connector 62, which in turn is connected to refrigerant fluid outlet line 32. FIG. 5 further shows the placement of two split-disc 64 and 66 within cylindrical housing 12. Discs 64 and 66 are slip-fitted within housing 12 and generally positioned to separate the housing 12 into three separate compartments A, B and C. The discs 64 and 66 serve to further reduce eddy currents and mixing of the coolant fluid within housing 12 during operation at higher flow rates. Discs 66 and 68 are constructed identically, and a perspective view of disc 66 is shown in FIG. 6. Disc 66 has a split 70 extending from the outer circumference 72 of disc 66 to an inner bore 74 within disc 66. Inner bore 74 is large enough to allow first and second outlet coil tubes 54 and 56 encased by insulating sleeve 38 to pass through disc 66. The split 70 allows disc 66 to twist slightly to accommodate fitting around the coil arrangement 40. Disc 66 further has multiple bores 76 spaced along the edge of disc 66. These bores allow warmer coolant fluid to rise up through the housing 12 enhancing the "stacking" phenomenon utilized in the present invention and reducing the possibility of eddy currents or mixing. Testing has shown that the taller and narrower the invention, the more efficient the device. The preferred embodiment of FIG. 2 calls for 4" polyvinyl chloride (PVC) pipe, 30" high, with 4" PVC top and bottom caps. The coil is constructed of 3/8" copper tubing wound into a 31/2" diameter coil. The above stated sizes have been found to satisfactorily serve to improve the operation of air conditioner units up to 5 ton capacity. For air conditioner units above 5 ton capacity, testing has shown that maintaining a height to diameter ratio in inches of 7.5:1 yields the best results. Ratios as low as 4:1 will operate. No upper limit on ratios has been documented.

A cylindrical convection heat dissipation tower is shown having a top and bottom cap with wound heat exchange coils dispersed within the tower. Cooling fluid is introduced gradually at the bottom of the tower while warmer cooling fluid is discharged from the top of the tower. The tower utilizes "stacking" principles to gradually lower the temperature of the refrigerant fluids entering at the top of the tower, passing downwardly through the coils, and rising upwardly through an insulated portion of that coil, exiting from the top of the tower.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to waveguide structures and more particularly to waveguide multiplexers/demultiplexers. 2. Description of the Related Art Frequency-division multiplexing is the process of transmitting a plurality of input signals over a common transmission path by assigning a different frequency channel for each signal. Thus, the combined signals can subsequently be separated by filtering and by providing separate transmission paths for the filtered signals. The filtering and providing processes are those of frequency-division demultiplexing. Because demultiplexing is the inverse function of multiplexing, the following discussion is restricted, for simplicity, to multiplexing. Low-loss, high-power frequency-division multiplexing in the microwave region is facilitated by the use of waveguide multiplexers which typically form a plurality of input ports for the reception of microwave input channel signals and a single output port for delivery of the multiplexed signals onto a common transmission path. Generally, this path leads to common signal-processing structures, e.g., a microwave amplifier or a radiating antenna. In conventional waveguide multiplexers, a plurality of input waveguides (typically referred to as tee's) are joined to a single output waveguide (typically referred to as a manifold) in a way that enhances electromagnetic signal transfer. For example, each tee is arranged to form an E-plane junction with the manifold in one exemplary multiplexer structure and an H-plane junction in another. In most multiplexer waveguide structures, the manifold has an open-circuited end for transmission of the multiplexed input signals. Opposite the open-circuited end, the manifold has a short-circuited end and the tees are spaced by selected distances from the shorted end. Each tee also terminates in a short-circuited end and forms an aperture in this short-circuited end for signal access to that tee. A waveguide filter is coupled to the aperture so that channel filtering is associated with signal transmission through the tee. In practice, a number of problems complicate multiplexer design. First, each input signal travels down its respective tee and splits into two signals which propagate in opposite directions along the manifold. One signal propagates towards the manifold's open-circuited end and the other propagates to, and is reflected from, the manifold's short-circuited end. Tee and manifold distances must therefore be carefully chosen so that each reflected signal from the manifold's short-circuited end adds to signals entering the manifold from that reflected signal's respective tee, i.e., these signals must be substantially in phase when they meet. Secondly, the reflected signals from the manifold's short-circuited end again split as they successively reach each tee, with one signal portion propagating down the manifold and the other portion propagating up that tee and being reflected from that tee's short-circuited end. Tee and manifold distances must also be chosen so that signals reflected from tee shorted ends arrive in phase with signals entering the manifold from that reflected signal's respective tee. Because they lie in different frequency channels, each of the input signals propagates with a different guide wavelength λg. A successful multiplexer design must therefore take the different propagation wavelengths into account and realize a dimensional layout that enhances signal additions at each tee so as to enhance the transmitted channel energy at the manifold's open-circuited end. Multiplexer design is further complicated by impedance mismatches at the junctions of the tees and the manifold which generate additional signal reflections. An acceptable multiplexer design must reduce these impedance mismatches as much as possible and yet accommodate the reflected signals from the remaining mismatches. Impedance mismatches can result in an apparent electrical short circuit wall at a specific frequency. A manifold resonance can be created between this apparent electrical wall and the manifold's short-circuited end or any one of the tee short-circuited ends. These types of resonances further degrade multiplexer performance. In addition, multiplexer transmission-line discontinuities (e.g., tee-manifold junctions) generate higher-order electromagnetic modes. Because multiplexers are generally associated with nonlinear processes (e.g., high-power amplification), the input signals typically include frequency harmonics and this combination of discontinuities and harmonics generates higher-order harmonic modes which propagate in the multiplexer with different guide wavelengths. At other discontinuities (e.g., downstream waveguide junctions), energy is exchanged between these propagating modes. A successful multiplexer design must also control the energy exchanges of propagating higher-order modes in order to enhance the transmitted channel energy. These complications of multiplexer design generally increase exponentially with each additional frequency channel that is included in the multiplexer. It has been found, for example, that although a satisfactory design can be found relatively quickly for an eight channel waveguide multiplexer, a satisfactory design for a sixteen channel multiplexer is exceedingly difficult to obtain. SUMMARY OF THE INVENTION The present invention is directed to multiplexer/demultiplexer structures and methods which facilitate simpler and less expensive design solutions than are conventionally available. In particular, structures and methods of the invention reduce the number of tees that are required for a given number of multiplexer channels. Multiplexer/demultiplexer designs which conventionally would have been complex and expensive are thus transformed into simpler, lighter, smaller and less expensive designs. Because the number of junctions are reduced, multiplexer/demultiplexer structures of the invention also exhibit improved performance. These goals are realized with a primary waveguide and at least one secondary waveguide which is joined to the primary waveguide and which forms at least first and second apertures for signal access to the secondary waveguide. A plurality of waveguide filters are multiplexed to each secondary waveguide by coupling each through a respective one of the apertures. Signal isolation is obtained with a septum that is positioned between each adjacent pair of apertures. The septum is preferably dimensioned to create an aperture-to-aperture transmission path that is sufficiently long (e.g., greater than (¼)λ g avg ) to significantly reduce higher-order modes and, therefore, aperture interactions. Different embodiments of the invention can be formed with various waveguide configurations (e.g., circular, rectangular or dielectric) and with different tee-manifold junctions (e.g., E-plane and H-plane junctions). The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a communication spacecraft in an orbital plane about the Earth; FIG. 2 is a block diagram of a transponder in the spacecraft of FIG. 2 wherein the transponder includes a demultiplexer and a multiplexer; FIG. 3 is an enlarged, perspective view of multiplexer structure of the present invention that is included within the curved line 3 of FIG. 2; FIG. 4 is view similar to FIG. 3 which illustrates another multiplexer structure of the present invention; FIG. 5 is a perspective view of another multiplexer structure of the present invention; and FIG. 6 is a graph of measured transmission and reflection characteristics in a prototype of the multiplexer structure of FIG. 3 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 3, 4 and 5 illustrate multiplexer/demultiplexer embodiments of the present invention and FIGS. 1 and 2 illustrate an exemplary use of the invention. For descriptive simplicity, the multiplexer/demultiplexer embodiments will be described principally from a multiplexer perspective. The multiplexer structures exemplified by FIGS. 3, 4 and 5 employ signal-isolating septums which reduce signal interactions and facilitate the multiplexing of multiple input signals through a single tee. Accordingly, the number of tee's required for a given number of multiplexer channels can be significantly reduced with consequent lowering of the complexity and cost of multiplexer designs and the size, weight and cost of fabricated multiplexers. In multiplexers with a large number of frequency channels (e.g., ≧16), tee reductions of the invention may even enable the realization of an otherwise unrealizable multiplexer. To enhance its clarity, a description of multiplexer structures of FIGS. 3, 4 and 5 is preceded by the following description of FIGS. 1 and 2. As shown in FIG. 1, a spacecraft communication system is carried by a spacecraft 20 (e.g., a body-stabilized or spinner spacecraft) which orbits a celestial body such as the Earth 22 in an orbital plane 23 . The spacecraft 20 includes a body 24 which carries a pair of solar wings 25 and 26 to receive solar radiation and convert it into electrical energy for operation of the spacecraft's systems. The spacecraft body 24 also carries receive and transmit antennas 28 and 29 for communication with Earth-based communication stations. Typically, the spacecraft 20 also carries systems (e.g., thrusters 30 and 31 ) for maintaining the spacecraft's assigned orbital station and for maintaining a spacecraft attitude that enhances signal exchange between the spacecraft and the communication stations. As shown in FIG. 2, a frequency converter/amplifier 42 is coupled between the receive and transmit antennas 28 and 29 to form a transponder system 40 . The converter/amplifier 42 has a plurality of amplifiers 43 arranged between a demultiplexer 44 and a multiplexer 46 . This structure is fed by a frequency conversion subsection 48 in which a mixer 50 and a local oscillator signal 51 are used to frequency convert the output of a low-noise amplifier 52 . The frequency conversion subsection 48 may also include pre-amplifiers 54 at the converted channel frequencies. The low-noise amplifier 52 is coupled to the receive antenna 28 . Each of the amplifiers 43 is dedicated to a respective frequency channel of the transponder 40 . In the demultiplexer 44 , channel bandpass filters 56 are coupled through secondary waveguides in the form of tees 58 to a primary waveguide in the form of a manifold 60 which connects to the subsection 48 . Each of the channel filters 56 is connected to a respective one of the amplifiers 43 . Similarly, channel bandpass filters 62 are coupled through tees 64 to a manifold 66 of the multiplexer 46 . Each of the channel filters 62 is connected to a respective one of the amplifiers 43 and the manifold 66 couples to the transmit antenna 29 through output filters 68 . The output filters 68 are configured to reduce harmonics and higher-order electromagnetic modes which would otherwise degrade the radiating performance of the output antenna 29 . In its operation, the transponder 40 receives input communication signals in a receive frequency band through the receive antenna 28 , converts the received signals to a transmit frequency band, amplifies the frequency-converted channel signals and retransmits the converted and amplified signals through the transmit antenna 29 . In an exemplary communications system, the transponder's receive antenna 28 might be configured and oriented to receive signals from a single Earth-based station and the transponder's transmit antenna 29 might be configured and oriented to transmit signals to an area of the Earth for reception by a plurality of Earth-based stations. The manifold 66 of the multiplexer 46 has an open-circuited end 72 which couples the combined signal channels to the output filters 68 and output antenna 29 . Opposite the open-circuited end 72 , the manifold 66 has a short-circuited end 74 . The tees 64 are spaced from the short-circuited end 74 by distances which are selected to enhance signal addition between channel signals exiting the tees and channel signals which are generated by various reflection generators (e.g., tee and manifold short-circuited ends and waveguide impedance mismatches). The microwave amplifiers 43 are typically high-power microwave amplifiers (e.g., traveling-wave tubes) which generate frequency harmonics because their amplification is a nonlinear process. In addition, signals passing through the transponder 40 typically encounter transmission-line discontinuities (e.g., waveguide bends and junctions) which generate higher-order electromagnetic modes. This combination of frequency harmonics and transmission-line discontinuities gives rise to manifold resonances and propagating higher-order modes whose energy exchanges at other transmission-line discontinuities further complicate multiplexer design. As stated above, these complications cause conventional multiplexer designs for high numbers of channels to be exceedingly complex and expensive. Although these multiplexer problems have been described with reference to spacecraft, they occur in many other communcation structures (e.g., communication ground stations). Accordingly, an embodiment 80 of the multiplexer 40 includes the structure of FIG. 3 which shows the manifold 66 and one of the tees 64 A forming an E-plane junction 81 . In contrast to conventional multiplexer structures, a pair 62 A and 62 B of the channel filters of FIG. 2 are coupled to a short-circuited end 82 of the tee 64 A. The shorted end forms first and second apertures 83 A and 83 B for signal access to the tee 64 A and the filters 62 A and 62 B are respectively coupled through the apertures 83 A and 83 B to the interior of the tee. A septum 84 extends away from the short-circuited end 82 and is positioned between the apertures 83 A and 83 B to provide signal isolation. The short-circuited end 82 can be configured in various ways that provide physical clearance between the filters 62 A and 62 B. In FIG. 3, for example, opposite corners of the shorted end 82 are chamfered to angle the filters away from each other. In one multiplexer embodiment, the septum has a length 86 of (¼)λ g avg in which λ g avg is the average guide wavelength of channel signals that are processed through the tee 64 A. Thus, the septum 84 defines two subwaveguides in the form of reduced-height waveguides 88 A and 88 B which extend away from the short-circuited end 82 . Each of these waveguides forms a quarter-wave impedance transformer and, for signals having a guide wavelength substantially equal to λ g avg , these impedance transformers transform the short-circuited end 82 into an apparent open circuit (i.e., a very large impedance) at the opposite end of the septum 84 . In operation of this multiplexer embodiment, a channel signal is filtered through the filter 62 A and coupled through the aperture 83 A to then propagate down the reduced-height waveguide 88 A. As this channel signal reaches the end of the reduced-height waveguide 88 A, it “sees” the signal open-circuited that is presented by the quarter-wave transformer action of the reduced-height waveguide 88 B. Thus, the channel signal is inhibited from propagating into the latter waveguide and, instead, propagates down the remainder of the tee 64 A and into the manifold 66 where one signal portion 90 propagates towards the manifold's open-circuited end and another signal portion 92 propagates towards the manifold's short-circuited end (this propagation mode may be, for example, a TE 10 mode). A different channel signal filtered through the filter 62 B propagates in a similar series of processes so that both signals are multiplexed through the same tee. As stated above, a combination of frequency harmonics and transmission-line discontinuities gives rise to manifold resonances and propagating higher-order modes. The septum 84 is preferably dimensioned to create a transmission path from aperture to aperture (e.g., from aperture 83 A to aperture 83 B) that is sufficiently long that it significantly reduces the higher-order modes. Because the majority of higher order modes die out within (¼)λ g avg , a transmission path length which exceeds (¼)λ g avg (i.e., a septum length which exceeds (⅛)λ g avg ) will greatly reduce the higher-order modes and reduce apeture interactions. The teachings of the invention can be practiced with various conventional configurations of microwave channel filters. For example, the filters 62 A and 62 B are shown to each form a cylindrical cavity in which one transverse end wall forms a signal-entrance aperture 100 . As shown for filter 62 A, this main cavity is divided into two cylindrical cavities 102 and 103 by a transverse septum 104 which forms two orthogonally-arranged apertures 106 and 107 . Filters of this type support the existence of two different modes (e.g., TE 11x modes) which are coupled between the two cavities to realize a four resonator quasi-elliptic passband in a relatively small, lightweight filter. Other conventional microwave filters formed in various waveguides (e.g., rectangular or circular) to form various passband shapes (e.g., Chebyshev or quasi-elliptic) can be used to form equivalent multiplexer embodiments. Other tees can be junctioned with the manifold 66 to each carry multiple channel signals in a manner similar to that of the tee 64 A. As indicated in FIG. 3, these tees may extend from the same broad wall of the manifold as the tee 64 A (e.g., the tee 64 B) or from an opposite broad wall (e.g., the tee 64 C). Another multiplexer embodiment 110 is shown in FIG. 4 which is similar to FIG. 3 with like elements indicated by like reference numbers. In contrast to the embodiment 80 of FIG. 3, the tee 64 A and the manifold 66 are now arranged to form an H-plane junction 111 (other tees 64 B and 64 C are similarly arranged). Also the short-circuited end 82 need not be modified (i.e., chamfered as in FIG. 3) because the tee apertures 83 A and 83 B are now positioned in opposite broad walls of the reduced-height waveguides 84 A and 84 B. The H-plane junction arrangement of FIG. 4 facilitates this different aperture arrangement in which electric field vectors can exit the apertures 83 A and 83 B to be arranged across the narrow dimension of the reduced-height waveguides 88 A and 88 B. In FIG. 3, the tee apertures 83 A and 83 B are positioned in opposite narrow walls of the reduced-height waveguides 88 A and 88 B so that electric field vectors can exit the apertures 83 A and 83 B and be arranged across the narrow dimension of the reduced-height waveguides 88 A and 88 B. Yet another multiplexer embodiment 120 is shown in FIG. 5 which is similar to FIG. 3 with like elements indicated by like reference numbers. As in the embodiment 110 of FIG. 4, the tee 64 A and the manifold 66 are arranged to form an E-plane junction 81 . As in the embodiment 80 of FIG. 3, the tee's short-circuited end 82 is chamfered to facilitate multiple filter access to the tee 64 A but the chamfering is along the tee's broad wall. In the embodiment 120 , two septums 84 A and 84 B divide the tee 64 A into three reduced-height waveguides 88 A, 88 B and 88 C. Three waveguide filters 62 A, 62 B and 62 C are coupled through the short-circuited end 82 for respective access to the reduced-height waveguides 88 A, 88 B and 88 C. To provide physical clearance between the filters, they are each coupled to the shorted end 82 through an evanescent aperture 122 . The evanescent aperture is essentially a thick-walled aperture which is formed by a short waveguide whose cutoff frequency for harmonic higher-order modes is above the operating frequency of the embodiment 120 . In contrast to the embodiments 80 and 110 , the filters are arranged so that their electromagnetic fields couple out of a filter side wall and into the evansescent aperture 122 . Other embodiments of the invention may be configured with various waveguide members (e.g., rectangular or circular as shown by the broken line cross section 126 in FIG. 5 ), various junctions (e.g., E-plane or H-plane junctions) and various waveguide filter shapes (e.g., cylindrical, rectangular (as shown by the broken line 128 in FIG. 5) and spherical (as shown by the broken line 129 in FIG. 5) which realize various filter passbands (e.g., Chebyshev or quasi-elliptic). Although the filters 62 are coupled through narrow waveguide walls in FIGS. 3 and 5 and through broad waveguide walls in FIG. 4, other multiplexer embodiments can be formed that use a combination of these coupling arrangements. In accordance with the invention, filters can be multiplexed through common tees to form efficient multiplexers/demultiplexers in a variety of microwave frequency bands (e.g., C band, Ku band or Ka band). For example, FIG. 6 shows a graph 130 of measured signal transmissions and reflections in a prototype of the multiplexer structure of FIG. 3 . Plot 132 FIG. 6 shows reflection at the open-circuited end of the tee 64 A (where it joins the manifold 66 ). Plots 134 and 136 of FIG. 6 show transmission respectively from inputs of the filters 62 A and 62 B to the open-circuited end of the tee 64 A. As indicated, reflected signals were below −23 dB in the passbands of the filters and transmission loss in each passband was extremely low. While several illustrative embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Such variations and alternate embodiments are contemplated, and can be made without departing from the spirit and scope of the invention as defined in the appended claims.

A multiplexer/demultiplexer structure is provided which multiplexes multiple channel signals through a common tee of a tee/manifold mulitplexer arrangement. This multiplexing significantly reduces the number of tees required for a given number of multiplexed channels. Accordingly, mulitplexer/demulitplexer design time is reduced and fabricated multiplexers/demultiplexers are lighter, smaller and less expensive. The tee multiplexing is facilitated with multiple access apertures that are isolated by a septum. The septum forms reduced-height waveguides which define a path length between apertures that is sufficient to significantly reduce higher-order modes and, therefore, apeture interactions.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screwed attachment to an annular flange in a turbine engine in which the heads of the screws are covered by an annular fairing or bolt guard. When screws are used for fixing an element on an annular flange, particularly in turbine engine applications, it is necessary, when the heads of the screws are located in a streamline flow of air or gas, to cover them with an annular fairing or bolt guard in order to avoid harmful disturbances in the flow. 2. Summary of the Prior Art U.S. Pat. No. 3 727 660 describes an example of an application to a compressor in which a bolt guard is used and is furthermore arranged in such a way as to ensure retention of the elements in the event of accidental unscrewing or loss of an element for any reason in order thus to avoid such an element becoming entrained by the flow of gases and thereby causing any damage, which could be considerable. Despite its advantages, however, the solution proposed necessitates total caging of all the bolts which in some applications may present drawbacks with regard to the fitting and dismantling operations, particularly maintenance operations in which it is necessary to deal with only a single bolt, for example. SUMMARY OF THE INVENTION The aim of the invention is to provide a more satisfactory way of forming a screwed attachment including a bolt guard, which does not suffer from the drawbacks of the known solutions. To this end, according to the invention, there is provided attachment means for fixing a body of revolution to an annular flange in a turbine engine, comprising a plurality of evenly distributed screws, each of said screws having a head, an annular fairing forming a bolt guard over the heads of said screws, said bolt guard having means defining access holes to said screws in the face of said bolt guard opposite said screws, a plurality of first tubular sockets within said bolt guard and respectively aligned with said screws, said first sockets being wider than the heads of said screws and having first and second ends, said first ends being rigidly fixed to said bolt guard in the region of said access holes, and said second end of each of said first sockets having at least one notch-like cut-out, and a plurality of second tubular sockets respectively disposed within said first sockets, each of said second sockets having its inner end formed with at least one lug cooperating with said cut-out of the respective first socket, and at least one second lug curved inwardly and cooperating with the head of the respective screw in such a way as to prevent rotation of said screw. Preferably, the or each of the second lugs of each of said second sockets is cut from the side wall of said second socket and is deformed slightly inwardly with respect to said side wall, the inner edge of said second lug being folded inwardly at right angles and having a slightly off-centre semi-circular cut-out. Furthermore, each of the second sockets preferably comprises a cover at its outer end, said cover including means defining an oblong hole to facilitate withdraw of said second socket by means of a suitable tool. Further characteristics and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a diagrammatic general view of a turbine engine in which a screwed attachment asssociated with a bolt guard in accordance with the invention is used and is shown by a cut-away portion, seen as a longitudinal section in a plane passing through the axis of rotation of the turbine engine; FIG. 2 shows an enlarged view of the cut-away portion I in FIG. 1, seen as a longitudinal section in a plane passing through the axis of rotation of the turbine engine; FIG. 3 is an enlarged view of a detail from FIG. 2 illustrating the attachment shown in FIGS. 1 and 2; FIG. 4 shows a section on the line IV--IV in FIG. 3; FIG. 5 is an end view, looking in the direction of the arrow V, of a part of the attachment shown in FIG. 3; and FIG. 6 shows a section on the line VI--VI in FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENT The turbine engine 1 shown diagrammatically in FIG. 1 comprises, at the turbine output, an exhaust casing 2 on the downstream side of which is mounted a jet pipe (not shown in the drawings). As shown in greater detail in FIG. 2, the exhaust casing 2 comprises a hub 3 carrying on its upstream side an annular flange 4 provided with evenly distributed screw-threaded fixing holes 5. These holes 5 receive screws 6 which, in the embodiment shown in the drawings, are intended for fixing a ventilation cover 7 on the said flange 4. The heads 8 of the screws 6 are covered by an annular fairing which is made from sheet metal and is shaped to ensure good aerodynamic conditions for the flow of gases, the fairing constituting a bolt guard 9. The attachment means 10 in accordance with the invention and comprising the bolt guard 9 and screws 6 is shown in greater detail in FIGS. 3 to 6. In line with each screw 6 the bolt guard has an access hole 12 in the outer face of the fairing. In the annular space 13 within the bolt guard 9, situated between its outer face 11 and its inner face 14 and in which the heads 8 of the screws 6 are accommodated, there are first cylindrical sockets 15 each having a first end 16 rigidly fixed to the said outer face 11. In the embodiment shown, the end 16 of each socket 15 is welded to the circular edge 17 of a respective access hole 12. The two parts 11 and 14 of the bolt guard 9 may also be welded to each other in order to facilitate manufacture. The other end 18 of each of the first sockets 15 is provided with four notched-shaped cut-outs 19. Fitting within each of the first sockets 15 there is a second cylindrical socket 20, the inner end of which is cut to form two diametrically opposite first lugs 21 which, as can be seen in FIGS. 4 and 5, are slightly deformed outwardly in such a way that they can fit into the said cut-outs 19 on the first socket 15, and two second lugs 22 positioned in between the first lugs 21. One of the second lugs 22a is shown in the lower half of the view shown in FIG. 3 in the free position which is adopted by the lugs 22 when the socket 20 is not in use, and in which the inner edge of the lug is folded inwardly at a right angle and the lug itself is bent slightly inwardly. The other second lug 22b is shown in the upper half of FIG. 3 in the operative position of the lugs 22, in which the inner edge is engaged with the portion 8a of the head 8 of the corresponding screw 6. As can be seen from FIGS. 5 and 6, the inner edge of each second lug 22 comprises a semi-circular cut-out 23 which is slightly off-centre. The portion 8a of the head of each screw 6 is serrated to form external teeth 24, and one of these teeth is engaged in the cut-out 23 of one of the second lugs 22. The outer end of the second socket 20 has a cover 25 in which there is an oblong hole 26. The method of mounting the assembly which has just been described is as follows. The bolt guard 9 with the internal sockets 15 is positioned over the members which are to be assembled, ie. the ventilation cover 7 and the annular flange 4 of the exhaust casing 2, and the screws 6 are inserted and tightened in the screw-threaded holes 5 of the said flange, passing through the access holes 12 and through fixing holes 27 provided in the inner part 14 of the bolt guard 9 so that the heads 8 of the screws 6 bear on the edges of these holes 27. The second sockets 20 are then inserted into the first sockets 15 in the bolt guard 9 via the access holes 12 in such a way that the first lugs 21 can click into cut-outs 19 of the first sockets 15, and the inner edge of the second lugs 22 engage over the teeth 24 on the head portions 8a of the screws 6. In the embodiment shown in the drawings, there are twelve teeth 24 on each screw, and the cut-outs 23 of the lugs 22 which cooperate with them are offset by a twenty-fourth of a turn in such a way as to ensure secure engagement of a tooth 24 in one of the cut-outs 23. As a consequence of the arrangement described, each screw 6 is rotationally locked by the engagement of the teeth 24 on the screw head 8 with the second lugs 22 of the second socket 20, which is itself locked by the first lugs 21 in engagement with the first socket 15 which is rigid with the fixed assembly. Any accidental slackening is thus avoided. In the extreme case where a breakage or damage to the lugs 21 would make it possible for a screw 6 to become unscrewed, the second socket 20 remains attached to the head of the screw 6 by means of the lugs 22. The assembly obtained retains the facility for dismantling and it is possible to perform an operation on the screws 6 individually. Indeed, it is sufficient to engage a suitable tool by a quarter of a turn in the oblong hole 26 in the cover 25 of the second socket 20, and then to pull on the socket in order to disengage not only the first lugs 21 from the cut-outs 19 of the first socket 15 but also the second lugs 22 from the teeth 24 of the screw head 8. The risks of premature wear and tear after several fitting and dismantling operations are reduced by reason of the fact that only a resilient deformation of the lugs of the second socket 20 occurs in order to ensure locking of the whole attachment assembly. In the embodiment described and shown in the drawings, the bolt guard 9 also comprises, on the downstream side, an annular groove 28 which receives the upstream edges 29 of heat protecting tiles 30 on the hub 3 of the exhaust casing 2 of the turbine engine.

An annular fairing forming a bolt guard associated with the heads of screws of an attachment carries, inside thereof and in line with each screw, first cylindrical sockets each of which comprises notch-shaped cut-outs at its inner end which cooperate with a pair of first lugs formed at the end of a respective second socket disposed within the first socket and further comprising a pair of inwardly curved second lugs cooperating with the head of the screw in such a way as to prervent rotation of the screw.

This is a continuation of application Ser. No. 000,585, filed Jan. 2, 1979 which is itself a continuation of U.S. Ser. No. 745,928, filed Nov. 29, 1976, both now abandoned. BRIEF SUMMARY OF THE INVENTION The present invention relates to a vulcanizable polyblend comprising a thermoplastic copolyester and a synthetic or natural rubber. The present invention further relates to a vulcanized molded article which comprises an elastomeric intimate polyblend of a thermoplastic copolyester and a vulcanized synthetic or natural rubber. Vulcanized natural or synthetic rubbers are widely used for a variety of purposes, such as tubings/hoses, tires, belts, coated fabrics and sealants in the automobile industry. Such rubbers, however, have various defects and have a restricted usage. For example, SBR (styrene-butadiene rubber) and NR (natural rubber) exhibit poor tensile and tear strength, and poor oil resistance. NBR (nitrile rubber) is comparably superior in oil resistance, but it is sensitive to oxygen or ozone at an elevated temperature. CR (chloroprene rubber) and EPDM (ethylene-propylene-diene rubber) has comparatively good resistance to deterioration caused by heat or oxygen, but they lose their elastomeric properties in certain oils such as ASTM #3 oil or Fuel D. Therefore, there has been needed a rubber having a good elastic property at both low and high temperatures, a good oil resistance, a good abrasion resistance and a good oxygen or ozone resistance. Furthermore, recently polyester fibers or fabrics are popular as reinforcing materials because of their excellent rigidity and high modulus. It is strongly desired to improve the adhesive properties of rubbers to polyester. Thus, the principal object of this invention is to provide an elastomeric compound having good resilience at low and high temperatures, heat and oxygen/ozone resistance, excellent oil and fuel resistance, impact strength, good abrasion property and increased scuff resistance. In addition, the blends which are rich in the copolyester exhibit superior ozone resistance, oil and fuel resistance, improved stiffness, impact resistance and electric insulating properties, and the mechanical strength is maintained even at an elevated temperature. Another object of this invention is to provide a rubber composition having a good adhesive strength to polyester fibers or fabrics. We have found, the foregoing objects are achieved by blending a thermoplastic copolyester with a synthetic or natural rubber and vulcanizing the polyblend. It is a surprising discovery that copolyester or copolyester elastomer is so compatible with rubber than an intimate blend is achieved. DETAILED DESCRIPTION OF THE INVENTION The thermoplastic copolyesters useful for the polyblend of this invention include in general, linear saturated condensation products of diols and dicarboxylic acids, or reactive derivatives thereof and block copolyetheresters. Examples of the dicarboxylic acid are terephthalic acid, isophthalic acid, orthophthalic acid, azelaic acid, sebacic acid, adipic acid, dodecandicarboxylic acid, naphthalenedicarboxylic acid, cyclohexane dicarboxylic acid etc. Diols used in this invention are ethylene glycol, 1,4-butanediol, 1,2- or 1,3-propanediol, 1,6-hexanediol, xylylene diglycol, cyclohexane-dimethanol and 1,4-cyclohexane diol. Preferably, the copolyesters may be the condensation polymers prepared from a dicarboxylic acid component comprising 50-95 mol% of terephthalic acid and a glycol component comprising at least 50 mol% of 1,4-butanediol. More preferably the glycol component consists essentially of 1,4-butanediol. The block copolyetherester useful for the polyblend of this invention are generally produced by reacting at least one long chain glycol with at least one low molecular weight diol as mentioned above, and at least one dicarboxylic acid, as mentioned above. The long chain diols include poly(alkylene oxide)glycols wherein the alkylene group has 2-10 carbon atoms, such as poly(ethylene oxide)glycol poly(propylene oxide)glycol poly(ethylene-propylene oxide)glycol poly(tetramethylene oxide)glycol poly(hexamethylene oxide)glycol, and poly(decamethylene oxide)glycol poly butadiene diol is also used as a long chain diol component. The long chain polyether glycol has a molecular weight of 400-6000, preferably 500-4500. Ratio of the short ester segment to the long ether segment is from 15/85 to 90/10. Preferably, they comprise polyhatylene terephthalate-poly(tetramethylene oxide)glycol or polybutylene tere/iso phthalate-poly(tetramethylene oxide)glycol or polybutylene tere/ortho phthalate-poly(tetramethylene oxide)glycol. The copolyester or block copolyester elastomer may preferably have a relative viscosity of more than 1.2 measured by the standard method using 1.5 g of polymer per 100 ml of orthochlorophenol at 25° C. The copolyester or block copolyester elastomer may have a melting point of from 80°-220° C., preferably from 100°-200° C. vulcanizable rubbers used in the present invention include SBR, NBR, CR, EPDM rubber and natural rubbers. Preferably, nitrile rubber or chloroprene rubber are used. A nitrile rubber modified by copolymerizing α,β-unsaturated carboxylic acid monomer may also preferably be used. The polyblend of the present invention may comprise about 5 to 90% by weight of a thermoplastic copolyester and about 95 to 10% by weight of a vulcanizable synthetic or natural rubber. The preferred polyblend may comprise about 5 to 50% by weight of a thermoplastic copolyester and about 95 to 50% by weight of a vulcanizable synthetic or natural rubber. By using major amount of the rubber component a fine dispersion of copolyester component can be attained and a more excellent article can be obtained. The polyblend of copolyester and unvulcanized rubber may be prepared by merely mixing those components at a sufficiently elevated temperature to soften or melt them until a uniform blend is formed. It is important in order to obtain the best result that the size of the finely divided particles in the blend does not exceed 50μ preferably 10μ, which is easily achieved by the simple mixing of the components in this invention. Suitable mixing devices include heated rubber mills. "Banbury mixers" and/or extruders, preferably twin barrel extruders or single extruders fitted with a mixing attachment on the screw. The blending is also carried out by mixing the polyester emulsion with an unvulcanized rubber emulsion followed by coagulation of the mixed emulsion and then kneading the resultant solid portion at an elevated temperature. A vulcanizing agent may be added to the polyblend at any stage before vulcanization. The polyblend can be injection-, compression-, transfer-, and blow-molded to form elastic molded articles after adding a vulcanizing agent. They can be also readily extruded to produce tubing, film and cross-head extruded for hose, wire, cable and laminates. They can also be easily calendered to produce films and sheeting, to produce calender coat woven and non-woven fabrics such as polyester fabrics or polyester tire cords. The molded or shaped articles are vulcanized under a conventional method and under a conventional condition for the rubber component contained in the polyblend. As a vulcanizing agent, zinc oxide, an oxide of a Group II metal of the Periodic Table, sulfur, an organic peroxide or their mixtures in combination with accelerators or retarders such as mercaproimidazoline, diorthotolyl guanidine, benzothiazyl disulfide, (zinc salt of) 2-mercaptobenzothiazole, tetramethylthiuram disulfide, tetramethylthiuram monosulfide, zinc diethyl dithio carbonate, ethylene thiourea and cyclohexyl benzothiazyl sulfonamide may be used in the present invention. Although the blend of this invention possesses many desirable properties, the composition may be stabilized against heat or oxygen/ozone or UV-radiation. This can be performed by the incorporation of stabilizers into the blend. Satisfactory stabilizers comprise phenols and their derivatives, amines and their derivatives, compounds containing both hydroxyl and amine groups, hydroxyazines, oximes, diarylosazones, diacetyl diarylosazones, N-substituted ureas, bisphenol sulfides, diamino durenes, ρ-alkoxy-N-akylanilines, benzophenones and benzotriazoles. Representative compounds useful as stabilizers include aldol-α-naphthyl amine, 1,2-dihydro-2,2,4-trimethylquinoline, N-isopropyl-N'-phenyl-ρ-phenylene diamine, phenyl-β-naphthyl amine, N,N'-diphenyl-ρ-phenylene diamine, N,N'-di-β-naphthyl-ρ-phenylene diamine, 2,2'-methylene-bis (4methyl-6-t-butyl phenol), 2-mercaptobenzoimidazole, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, N-isopropylxanthate, 1,3-dibutylthiourea. The properties of the composition can be moldified by incorporation of various conventional inorganic fillers, such as carbon black, zinc oxide, titanium oxide, silica gel, aluminum oxide, whisker, wallastenite clay and glass fiber. The composition may also contain various additives such as plasticizer, pigments, flame retardants, nucleating agents, and blowing agents. The vulcanized elastomeric molded articles of the present invention may be economically and practically applied to a variety of purposes, such as a tubing, hose, tire, belt, wire coating, shock-absorber, acoustical sealant, electric insulator, coated fabric, sealant, O-ring, shoe soling, heel lift, packaging materials, flooring materials, roofing materials, automotive applications, factory applications and gears. The following examples further illustrates the invention. EXAMPLE 1 Copolyester (A) In a glass flask having stainless steel stirrer with helical ribbon type screw, 94.5 parts of dimethyl terephthalate, 41.5 parts of dimethyl isophthalate, 94.5 parts of 1,4-butanediol and 62.0 parts of poly(tetramethylene oxide)glycol having a molecular weight of about 1000 were placed in the presence of 0.10 parts of tetrabutyl titanate. The mixture was heated with stirring at 210° C. for 2 hours to distill off methanol from reaction system. The recovered methanol was 42.6 parts corresponding to 95% of the theoretical weight. After adding 0.42 parts of "Irganox"1098 to the reaction mixture, the reaction temperature was then raised to 245° C. and the pressure on the system was reduced to 0.2 mmHg for a period of 50 minutes. Polymerization was continued for 2 hours under these conditions. The intrinsic viscosity of the product in orthochlorophenol at 25° C. was 1.05 and the polymer showed a melting point of 160° C. Copolyester (B) Using 199 parts of dimethyl terephthalate, 216 parts of 1,4-butanediol and 200 parts of poly(tetramethylene oxide)glycol under the same reaction conditions as in copolyester A), copolyester (B) was prepared. The copolyester (B) exhibits a melting point of 201° C. and an intrinsic viscosity of 1.50. Elastomer Compositions Blends of copolyester (A) or (B) with some types of unvulcanized rubbers were prepared in the following blend ratios using an extruder (having 30 mm φ screw) and heated at 200° C. After mixing, the desirable vulcanizing agents, vulcanizing auxiliary agents and vulcanization accelerators were added to the blended rubber on a roller mill at from 70°-80° C., the vulcanization was performed at a temperature of from 140°-150° C. for 30 minutes using a press mold. Typical properties of these blends were listed in Table 1 in comparison with unblended rubbers. TABLE 1__________________________________________________________________________ Example ControlNumber 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 1-12__________________________________________________________________________Copolyester A A A A A A B B -- -- -- --Rubber SBR*.sup.1 SBR SBR NBR*.sup.2 CR*.sup.3 EPDM*.sup.4 NBR SBR SBR NBR CR EPDMBlend ratio (75/25) (50/50) (25/75) (25/75) (25/75) (25/75) (50/50) (50/50) (0/100) (0/100) (0/100) (0/100)(copolyester/rubber)Thermal Resistance*.sup.5 (%) 98 90 77 90 82 88 95 93 36 56 53 79UV Resistance*.sup.6 (%) 98 82 61 55 70 72 62 86 25 20 65 58Oil Resistance*.sup.7 (%) 6 14 16 10 16 23 6.8 9.9 44 14 21 51Compression Set*.sup.8 (%) 10 12 13 12 6.8 16 8.4 10 15 11 6.3 17Durometer Hardness*.sup.9 A 62 61 58 56 59 62 61 60 58 50 55 63__________________________________________________________________________ *.sup.1 SBR: Nippon Zeon "Nipol" 1502 *.sup.2 NBR: Nippon Zeon "Nipol" 1043 *.sup.3 CR: Du Pont "Neoprene" GNA *.sup.4 EPDM: Du Pont "Nodel" 1040 *.sup.5 Thermal Resistance: Retention of elongation at break after aging at 100° C. for 10 hours in gear oven. *.sup.6 UV Resistance: Retention of elongation at break after UV irradiation at 50° C. for 50 hours in PhadeO-Meter. *.sup.7 Oil Resistance: Weight increasing rate after immersion to ASTM No 3 Oil at 100° C. for 50 hours. *.sup.8 Compression Set: ASTM BMethod, 100° C., 70 hours. *.sup.9 Durometer Hardness: ASTM D2240 EXAMPLE 2 With 60 parts of copolyester (A) were mixed 40 parts of SBR, 5 parts of zinc oxide, 2 parts of stearic acid and 20 parts of carbon black on a Banbury mixer at 180° C. for 10 minutes. Then 2 parts of sulfur and 2.5 parts of benzothiazyldisulfide were added to the mixture on a rubber roll heated at 70° C. A portion was then molded and vulcanized at 150° C. under a pressure of 50 kg/cm 2 for 30 minutes. This vulcanized compound blend showed good elastic properties as listed in Table 2. TABLE 2______________________________________Physical Properties Test Method______________________________________Tensile Strength (kg/cm.sup.2) 450 ASTM D-412Elongation at Break (%) 430 D-412Tensile Set (%) 27 D-412(100% Strain)100% Modulus (kg/cm.sup.2) 80 D-797300% Modulus (kg/cm.sup.2) 140 D-797Durometer Hardness 88A D-2240______________________________________ EXAMPLE 3 By mixing 60 parts of SBR (Nippon Zeon "Nipol" 15024 with 40 parts of block copolyetherester (B) by a twin-screw extruder having 45 mm screws at 200° C., a finely mixed blend was prepared. To 100 parts of the blend, 4 parts of zinc oxide, 1 part of stearic acid, 10 parts of MPC black, 1.5 parts of sulfur and 1.5 parts of DM were added on a rubber mill at a temperature of 80° C., and then the compound was molded and vulcanized at 150° C. for 30 minutes. The properties of the resulting rubber blend are shown in Table 3 in comparison with four control rubber compositions. Control 1 SBR having no copolyester components. Control 2 The blend without the process of extrusion: Block copolyetherester (B) was blended with SBR and the same vulcanizing agents on a rubber mill. In this case, copolyetherester (B) did not finely disperse into the SBR matrix and formed a macro domain of about 50μ. Consequently the blend showed poor mechanical properties. Control 3 Blend of blockcopolyetherester with previously vulcanized SBR: When 40 parts of block copolyetherester (B) was blended with 60 parts of previously vulcanized SBR using an extruder heated at 200° C., the compatibility between the two components was too poor to form a finely divided structure. The mixture was press-molded to prepare test pieces. Control 4 Polybutylene terephthalate having an intrinsic viscosity of 1.2 was used in place of block copolyetherester (B) in Example 3. Blending was performed in the similar manner except at 240° C., and the resulting rubber blend showed a macro phase separation and poor elastic properties. TABLE 3__________________________________________________________________________ Control 4 Example polybutylene 3 1 2 3 terephthalate/ (B)/SBR SBR (B)/SBR (B)/SBR SBRComposition (40/60) (0/100) (40/60) (40/60) (40/60)__________________________________________________________________________divided state <<50μ -- >>50μ >>50μ >50μ(divided particle size) (1-10μ)Tensile Strength (kg/cm.sup.2) 200 110 120 140 400Elongation at Break (%) 460 600 50-300 25-400 30Shore Hardness A 62 60 60-70 59-75 95Compression Set (%)(100% Strain) 15 16 40 45 53Thermal Resistanceat 100° C. O X O O O__________________________________________________________________________ EXAMPLE 4 Substantially following the procedures described in Example 1, a block copolyetherester (C) was prepared from the following materials. ______________________________________Terephthalic acid 162 partsIsophthalic acid 87 parts1,4-Butanediol 240 partsPoly(tetramethylene oxide)glycol, 130 partsnumber average molecular weight1000______________________________________ 70 parts of "Hycar" 1072, nitrile rubber having pendant carboxylic groups prepared from 27% of acrylonitrile, 71% of butadiene, 2% of acrylic acid and 30 parts of copolyetherester (C) was blended in a 30 mmφ extruder heated at 200° C., and an almost transparent blend was prepared. To 100 parts of the blend were added 5 parts of zinc oxide, 1 part of stearic acid, 0.5 parts of sulfur, 1 part of cyclohexylbenzothiazyl sulfonamide (CZ) and 2 parts of tetramethylthiuram disulfide (TT) and kneaded on a rubber roller mill. Portion of the compound was then molded and vulcanized at 155° C. under a pressure of 50 kg/cm 2 for 30 minutes. For comparison nitrile rubber having no copolyetherester was prepared. TABLE 4______________________________________ Example 4 Control copolyester(C)/ nitrile rubber nitrileComposition (30/70) rubber______________________________________Tensile Strength (kg/cm.sup.2) 150 38Elongation at Break (%) 380 330Tensile Set (%) 4.0 4.5(100% Strain)100% Modulus (kg/cm.sup.2) 120 84After Aging at 100° C. for 50 hrTensile Strength (kg/cm.sup.2) 150 21Elongation at Break (%) 340 190100% Modulus (kg/cm.sup.2) 125 130Weight Increase after oil absorption(%)ASTM No. 3 oil 17 2470° C. × 50 hr______________________________________ EXAMPLE 5 In the similar manner as in Example 1, copolyester (D) was prepared from the following materials. ______________________________________Dimethyl terephthalate 126.1 partsDimethyl isophthalate 67.9 parts1,4-Butanediol 270 parts______________________________________ The copolyester (D) has a melting point of 168° C. and an intrinsic viscosity of 1.23. Seventy five parts of SBR ("Nipol" 1052) and 25 parts of copolyester (D) were subjected to a melt-compounding procedure by a 30 mmφ extruder heated at 200° C. A blend in which copolyester (D) particle was dispersed finely at about from 1-5 microns was prepared. To 100 parts of the blend were mixed 5 parts of zinc oxide and 2 parts of stearic acid on a Banbury Mixer for 30 minutes, and then 2 parts of sulfur and 2.5 parts of benzothiazyl disulfide were added and the mixture was kneaded on a rubber roll mill heated at 70° C. The resulting blended composition was molded and vulcanized at 150° C. under the pressure of 50 kg/cm 2 for 30 minutes. Test specimens were subjected to some tests listed in Table 5 with the test values therefor. TABLE 5______________________________________ Example Control 5 Copolyester(D) SBR______________________________________Tensile Strength (kg/cm.sup.2) 170 590 150Elongation at Break (%) 780 320 750Tensile Set (%) 19 90 15(100% Strain)300% Modulus (kg/cm.sup.2) 52 3,000 40Shore Hardness 70A 60D 56AAfter Aging at 100° C. for 7 hrTensile Strength (kg/cm.sup.2) 150 610 85Elongation at Break (%) 576 270 310Shore Hardness 73A 60D 74A______________________________________ EXAMPLE 6 In the manner described in Example 1 copolyester (E) was prepared from the following materials. ______________________________________Dimethyl terephthalate 113.5 partsDimethyl phthalate 61.1 parts1,4-Butanediol 121.5 parts______________________________________ The copolyester (E) exhibits a melting point of 170° C. and an intrinsic viscosity of 1.30. Seventy parts of nitrile rubber ("Hycar" 1042) and 30 parts of copolyester (E) were blended by a 30 mmφ extruder heated at 210° C. To 100 parts of the blend were added and mixed 5 parts of zinc oxide, 1 part of stearic acid, 25 parts of MPC black, 2 parts of sulfur and 1.5 parts of tetrathiuram disulfide on a rubber roll mill at 70° C., and the portion was molded and vulcanized at 150° C. for 30 minutes. For comparison a composition, of which copolyester component was added and kneaded along with above mentioned additives on a rubber roll mill heated at 70° C., was prepared and tested. TABLE 6______________________________________ Example 6 Control Copolyester Copolyester (E)/NBR (E)/NBR NBRComposition (30170) (30/70) (100)______________________________________Mixer for copolyester Extruder Roll heated --blend heated at 70° C. at 210° C.Particle size ofcopolyester in NBR matrix <50μ >>50μ -- (1-10μ)Tensile Strength (kg/cm.sup.2) 420 210 250Elongation at Break (%) 400 100-400 300JIS Hardness 71A 40-96A 67AOil Resistance excellent good goodAbrasion Resistance excellent good goodOzone Resistance good poor poorAdhesion topolyethyleneterephthalate excellent poor poorfabrics______________________________________

An intimate polyblend of about 5-90% by weight of a thermoplastic copolyester or block copolyester elastomer and about 95-10% by weight of a vulcanizable synthetic or natural rubber. The preferred copolyester is a copolyester of polybutylene terephthalate and the prefered block copolyetherester is polybutylene terophthalate-poly (tetramethylene oxide) glycol block copolyester. These polyblends can be vulcanized to elastomeric molded articles which exhibit an excellent oil and oxygen/ozone resistance even at elevated temperatures, a high impact strength, an increased scuff resistance and an improved flexibility at low and high temperatures. The vulcanized molded articles also have an improved adhesive property with polyester fibers or fabrics.

DESCRIPTION 1. Field of the Invention The invention disclosed broadly relates to semiconductor processes and more particularly relates to reactive ion etching techniques in integrated circuit fabrication processes. 2. Background of the Invention In the evolution of semiconductor fabrication processes, original field effect transistor devices were made by depositing a layer of metal on top of a gate insulator such as silicon dioxide. As device dimensions continued to decrease, it became more and more difficult to obtain good registration between the gate electrode structure and the edges of the source and drain diffusions in the silicon substrate. The prior art then evolved into the self-aligned silicon gate processes wherein the gate electrode was formed of a refractory material such as polycrystalline silicon which was deposited on top of a thin silicon dioxide gate insulator layer. This step would then be followed by the ion implantation of the source and drain regions into the silicon substrate, making use of the dimensions represented by the pre-existing gate structure, to define the edges of the resultant source and drain regions. This was called self-aligned silicon gate technology. As the technology further evolved, it was found that the relative conductivity of the polycrystalline silicon material which was employed not only as gate electrode structures but also as interconnection circuitry, was not sufficient to enable the efficient conduction of electrical currents. Thus, the technology evolved into the deposition of composite layers for the gate structure and the signal line interconnection structure. Typically, a layer of polycrystalline silicon was deposited followed by a layer of a refractory metal or metal silicide such as tungsten silicide. The higher conductivity of the tungsten silicide in the composite would enable improved conductivity for the electrical currents which had to be conducted therein. Reference to FIG. 1 will illustrate a cross-sectional view of such a composite of polycrystalline silicon layer 16 and tungsten silicide layer 18 on top of the silicon dioxide gate insulator layer 14 on a silicon substrate 10. The device region would be determined by the edges of the recessed oxide layers 12, and it is in that device region 13 that the field effect transistor device is to be formed by etching out the gate structure from the polycrystalline silicon layer 16 and tungsten silicide layer 18. Reference can now be made to FIG. 2 which shows the result of a typical prior art approach to forming the gate electrode structure 15. Typically, the thin oxide insulating layer 14 was approximately 250 angstroms in thickness, the polycrystalline silicon layer 16 was approximately 1500 angstroms in thickness, and the tungsten silicide layer 18 was approximately 2500 angstroms in thickness. On top of the tungsten silicide layer 18 there would typically be formed a patterned photolithographic layer of photoresist 20 whose outline dimensions would approximate the desired outline dimensions of the resultant gate electrode 15. In the prior art, reactive ion etching techniques would be employed using as a typical etchant, carbon tetrafluoride. The carbon tetrafluoride would be maintained at a pressure of approximately 25 milliTorr (mT) in a reactive ion etching chamber. Typical prior art reactive ion etching chambers apply a radio frequency field having a frequency of typically 13.56 MHz. In this RF field, the carbon tetrafluoride molecules would dissociate forming ionic species and neutral species which included carbon polyfluoride (CF x ) and fluorine. As is well-known in the prior art, any grounded element exposed to a positively charged plasma will acquire a net negative DC potential based on electrostatic principles. Thus, the positively charged ions of the etchant are attracted to this self-biased negative potential on the workpiece, such as the semiconductor wafer which is exposed to the plasma in the reactive ion etching chamber. Typically, CF 3 + ions are attracted to the workpiece and etch the silicon dioxide exposed. Fluorine ions are typically negatively charged and therefore are typically not in the vicinity of the workpiece. However, neutral and positively charged fluorine are attracted to the negatively biased workpiece and etch the silicon and the tungsten silicide which are exposed. Since neutrally charged fluorine atoms, molecules and free radicals outnumber positively charged fluorine ions in the vicinity of the negatively biased workpiece, and since these neutrally charged fluorine constituents are not dramatically influenced by the DC electric field in the vicinity of the workpiece, they tend to etch isotropically (in all directions), thereby producing poorly defined structures. Reference to FIG. 2 will illustrate the result of such poor directionality in the typical prior art reactive ion etching process. As can be seen, because of the poor directionality, the sidewalls 24 of the polycrystalline silicon layer 16 and the tungsten silicide layer 18 are undercut. This reduces the desired cross-sectional area for the current conducting electrode, thereby producing hot spots and possible catastrophic failure in the resultant integrated circuit device. In order to enhance the directionality, prior art workers would reduce the pressure of the ambient, thereby increasing the mean free path of flight and therefore the average kinetic energy per collision for the etchant ions. This would enhance the directional etching over the nondirectional etching action. However, by virtue of the higher kinetic energy, a greater amount of energy was available for any chemical reaction which would result once the etchant molecule came in contact with the workpiece molecule or atom. Therefore, little selectivity was maintained between the rate of etching for silicon and the rate of etching for silicon dioxide. Therefore, as can be seen in FIG. 2, over etching would frequently occur in the vertical direction so that the silicon dioxide gate insulator layer 14 would be etched completely through and a substantial portion (up to 1000 angstroms) of the silicon material on either side of the gate electrode 15, would be removed. The problem which would arise with this configuration, as shown in FIG. 2, is that undesirable charge states would be created in the resultant surface of the silicon adjacent to the gate electrode. This would result in poor field effect transistor properties and electrically deep junctions. Electrically deep junctions create the short channel effects which are undesirable for small dimensioned FET devices, as is well-known in the prior art. OBJECTS OF THE INVENTION It is therefore an object of the invention to provide an improved process for forming gate electrode structures in field effect transistor devices. It is another object of the invention to provide an improved semiconductor fabrication process for forming composite gate electrode structures in field effect transistor devices. It is still a further object of the invention to provide an improved semiconductor fabrication process which has a greater directionality and a greater selectivity in the etching of composite gate electrode structures for field effect transistor devices. SUMMARY OF THE INVENTION These and other objects, features and advantages of the invention are accomplished by the fabrication process disclosed herein. A four-step process is disclosed. The first step involves the use of a mixture of carbon tetrafluoride or an equivalent etching component mixed with a portion of molecular hydrogen or other suitable component which will getter the free fluorine produced in the reactive ion etching chamber. By gettering the free fluorine, anisotropic (directional) etching can be achieved. Step 1 is continued so that the tungsten silicide and polycrystalline silicon layers are etched almost completely through, but a residual 500 angstrom to 1000 angstrom thick layer of polycrystalline silicon is left at the bottom of the etched portions. The second step in the process then employs a mixture of the carbon tetrafluoride etchant and a higher proportion of hydrogen or other suitable component which will more extensively getter the fluorine ions, atoms and molecules. The resultant fluorine deficient ambient will result in the production of a layer of a fluorocarbon polymer on all exposed surfaces. The third step in the process provides for the removal of the protective fluorocarbon polymer layer from horizontal surfaces which are desired to be etched. A composition of, for example 50 percent molecular hydrogen and 50 percent molecular nitrogen is introduced to the reactive ion etching chamber at a relatively low pressure. This will enable a highly directional reactive ion etching of the polymer layer on horizontal exposed surfaces. Vertical exposed surfaces will not be etched as extensively because of the directionality of the etching ions, and therefore a protective coating remains on all vertical exposed surfaces, such as the sidewalls of the desired resultant gate electrode structure. The fourth step of the process then introduces carbon tetrafluoride or other suitable etchant and a small portion of oxygen into the chamber. This etchant removes the residual horizontal layer of polycrystalline silicon at the bottom of the etched areas, however it has a high selectivity for silicon and will not significantly etch the underlying silicon dioxide gate insulator layer. As a result, a very precisely defined gate electrode structure made up of composite layers of polycrystalline silicon and tungsten silicide, is formed without damage to the silicon substrate lying on either side of the gate electrode structure. DESCRIPTION OF THE FIGURES These and other objects, features and advantages of the invention can be more fully appreciated with reference to the accompanying figures. FIG. 1 is a cross-sectional view of a beginning stage in the inventive process, wherein a layer of polycrystalline silicon 16 and a layer of tungsten silicide 18 have been deposited over the silicon dioxide gate insulator layer 14 on the silicon substrate 10. FIG. 2 is a view of the result of a prior art process for the formation of a gate electrode in an FET device. FIG. 3 illustrates the first step in the inventive process, wherein an anisotropic (directional) etching step is carried out. FIG. 4 illustrates the second step in the inventive process, wherein the formation of a fluorocarbon polymer is carried out. FIG. 5 is an illustration of the third step in the inventive process, wherein the directional removal of the fluorocarbon polymer is carried out on all horizontal surfaces. FIG. 6 is an illustration of a fourth step in the inventive process, wherein the residual polycrystalline silicon layer 16' is removed from the bottom portion of each etched area. DISCUSSION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates the starting point for the inventive process disclosed herein. A silicon substrate 10 has had formed on its surface a recessed silicon dioxide layer 12, the edges of which form the device region 13. On the surface 17 of the silicon substrate 10 in the device region 13, a thin layer of silicon dioxide 14 is formed. Typically the silicon dioxide layer 14 has a thickness of approximately 250 angstroms and serves as the gate insulator layer in the final FET device. On top of the silicon dioxide layer 14 is deposited a layer of polycrystalline silicon 16 which typically has a thickness of approximately 1500 angstroms. The polysilicon layer 16 can typically be doped with phosphorus to form an N-type conductivity. Thereafter, a layer of a mixture of tungsten and silicon 18 can be formed on the surface of the polycrystalline silicon layer 16. In a subsequent high temperature sintering step, the tungsten silicide constituents in the layer 18 will be alloyed so as to form a tungsten silicide alloy. FIG. 3 illustrates the first step in the inventive process wherein an anisotropic (directional) etching step is carried out to etch through all of the tungsten silicide layer 18 which is desired to be removed and most of the polycrystalline silicon layer 16 which is desired to be removed. This is performed by introducing as an etching gas a mixture of carbon tetrafluoride and approximately 11 percent by volume of molecular hydrogen. The pressure of the etchant gas mixture is maintained at approximately 10 milliTorr and the power per unit area for the RF field is maintained at approximately 0.24 watts per square centimeter. The objective of the mixture of the etchant gas is to provide a highly directional reactive ion etch. In order to do this, reliance is placed upon the molecular hydrogen to chemically combine with the free fluorine produced in the chamber. Free fluorine, if not otherwise sequestered, will isotropically (nondirectionally) etch silicon and tungsten silicide surfaces. This will produce an undesirable undercutting which is to be avoided. Therefore, the molecular hydrogen is introduced to combine with the free fluorine to getter the fluorine so that the primary etching mechanism is ionized carbon trifluoride or carbon difluoride which is propelled in a vertical direction to contact and etch the exposed tungsten silicide and polycrystalline silicon layers 18 and 16. Other fluorine bearing etchant species can be employed to obtain the highly directional etching desired in this first step. For example, CHF 3 --H 2 (H 2 less than 10 percent); C 2 F 6 --H 2 (H 2 less than 25 percent); or other fluorine deficient plasma producing constituents. The unifying principle is that the hydrogen present will bind up the fluorine, thereby reducing the amount of free fluorine which can isotropically etch. As can be seen in FIG. 3, the first step anisotropic etching process is stopped at a point where from 500 angstroms to 1000 angstroms of residual polycrystalline silicon layer 16' remains on the surface of the silicon dioxide layer 14 in the regions desired to be etched. This end point detection is performed in the conventional manner. For example, many state-of-the art reactive ion etching chambers include optical spectroscopy or laser interferometric measurement tools which enable the operator to reliably detect an end point for etching, such as that shown in FIG. 3. The reason for stopping the etching process of step 1 before the polycrystalline layer 16 is completely etched through, is that the etching composition used in step 1 has a poor selectivity, and will not adequately distinguish between silicon dioxide and silicon in its etching rate. Another consideration and problem in the prior art is the degree of erosion of the photoresist layer 20 when exposed to prior art reactive ion etching compositions. Typically, the free fluorine present in the ambient of the etching chamber attacks the organic photoresist composition in layer 20, thereby reducing the precise delineation of the shape for the resultant structure to be formed. By gettering much of the free fluorine through the use of the molecular hydrogen as described for step 1 of the inventive process, less erosion is suffered for the resist layer 20. Therefore, a more sharply delineated resist image is maintained during the etching process. Turning now to FIG. 4, the second step in the inventive process is disclosed, wherein the formation of a fluorocarbon polymer is obtained for all exposed surfaces. In order to accomplish this, a significantly greater degree of gettering for the fluorine constituents in the ambient of the chamber is required. In order to accomplish this, the composition of the etchant gas mixture is modified to increase the proportion of molecular hydrogen. For example, a composition of carbon tetrafluoride and 42 percent by volume of molecular hydrogen has been found to be suitable for the preferential deposition of a fluorocarbon polymer on all exposed surfaces. This fluorocarbon polymer deposition process is further enhanced by increasing the pressure of the ambient to approximately 500 milliTorr and reducing the power level for the RF energy to 0.05 watts per square centimeter. In this manner, a layer of fluorocarbon polymer 30 is deposited on the vertical sidewalls of the gate structure 15, a layer of fluorocarbon polymer 30' is deposited on the horizontal surfaces at the bottom of the areas to be etched, and a layer 30" of fluorocarbon polymer is deposited on the top surface of the resist layer 20. The purpose of depositing the fluorocarbon polymer layer 30 is to protect the sidewalls 24 of the gate electrode structure from inadvertent etching by any free fluorine which happens to be in the vicinity and has not been adequately gettered by the molecular hydrogen, during the subsequent polysilicon etching step. Turning now to FIG. 5, step 3 of the inventive process performs the directional removal of the horizontal portions 30' and 30" of the polymer layer 30. In order to accomplish this, a suitable etchant gas mixture is introduced into the chamber which will remove the fluorocarbon polymer. An example of such a composition is 50 percent molecular hydrogen and 50 percent molecular nitrogen. This composition is introduced at a pressure of approximately 10 milliTorr, in order to provide the high directionality which is desired. A power level of approximately 0.24 watts per square centimeter is maintained. In this manner, the horizontal layers 30' and 30" of the fluorocarbon polymer are removed from all horizontal surfaces. The result of this step is shown in FIG. 5. FIG. 6 illustrates the fourth step in the inventive process, providing for the removal of the residual polycrystalline silicon layer 16' at the bottom horizontal surface of the areas to be etched. This is achieved by introducing an etching composition of carbon tetrafluoride and approximately nine percent by volume of molecular oxygen. This composition is provided since it will not etch in any substantial way, any exposed silicon dioxide layers. However, at a pressure of approximately 100 milliTorr and a power density of approximately 0.10 watts per square centimeter, the etchant does not have a very good directionality, and therefore there is some slight undercutting at the very base of the polycrystalline silicon layer 16 where the polycrystalline silicon residual portion 16' is removed. However, the undercutting is slight and is not considered harmful. As can be seen in FIG. 6, the remaining fluorocarbon polymer layer 30 on the sidewalls 24 of the gate electrode structure 15 protects the sidewalls 24 from any further etching by the etchant composition in step 4 of FIG. 6. As a result, the resulting gate electrode structure 15 has a full, designed-for cross-section which enables relatively high current conduction to be maintained. The resulting inventive process provides a well-defined precisely dimensioned gate electrode structure while at the same time preventing any unwanted etching of the silicon substrate in the region surrounding the gate electrode structure. Although a specific etching composition, pressures and power densities have been described above, other compositions and process parameters can be employed without departing from the spirit of the invention. For example, the gate electrode composite structure 15 can be a layer of polycrystalline silicon 16 which has a refractory metal silicide layer 18 on top of it. Such suitable refractory metal silicides can be in addition to tungsten silicide, tantalum silicide, molybdenum silicide, titanium silicide, and niobium silicide. With regard to possible alternate etching gas compositions for producing the polymer layer in step 2 described above, the following alternate compositions can be employed as substituting for the preferred embodiment of CF 4 --42 percent H 2 . Alternate compositions can include CF 4 --H 2 where the proportion of H 2 can be any proportion greater than 40 percent and less than 75 percent by volume. Other alternate compositions can include C 2 F 6 --H 2 where the H 2 proportion is greater than 25 percent by volume. Also, CHF 3 --H 2 where the H 2 proportion is greater than 10 percent by volume. In addition, C 3 F 8 without the addition of any additional H 2 . Still further, CH 2 F 2 can be employed or CH 3 F can be employed, each without the addition of any additional H 2 . Another alternate composition is CHF 3 --C 2 F 6 , wherein the C 2 F 6 proportion is greater than 20 percent. Still another alternate composition is C 2 H 2 --C 2 F 6 where the C 2 F 6 proportion is greater than 40 percent by volume. Each of the above alternate compositions behaves under the unifying principle that free fluorine is bound up, thereby increasing the tendency to form the polymer. Indeed, the greater the carbon-to-fluorine atomic ratio in the compositions, the greater will be the tendency to form a polymer. Other alternate compositions for the etchant which will directionally etch the polymer in step 3, include molecular oxygen, molecular hydrogen, molecular nitrogen, a mixture of molecular hydrogen and molecular nitrogen, and molecular ammonia. A unifying principle for the selection of these etching compositions is that they be introduced at a relatively low pressure of less than 25 milliTorr. The relatively low pressure increases the mean free path for the ions in the etching chamber, thereby enhancing the directionality of their etching action. Although a specific embodiment of the invention has been disclosed, it will be understood by those of skill in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and the scope of the invention.

A reactive ion etching technique is disclosed for etching a gate electrode out of layers of tungsten silicide and polycrystalline silicon without etching the underlying layer of silicon dioxide which serves as the gate dielectric and which covers the source and drain regions. The key feature of the invention, wherein the gate, which has been partially etched out of the tungsten silicide and polycrystalline silicon layers, is coated with poly tetra-fluoroethylene (teflon) to protect the sidewalls of the gate from being excessively etched in the lateral direction while the etching continues at the bottom on either side of the gate. The process is especially suitable for formation of tungsten silicide structures since no subsequent thermal steps are required which would otherwise cause a delamination of the tungsten silicide. In addition to eliminating undercutting, the process does not disturb the gate oxide over the source and drain areas, which would otherwise create a leaky device unsuitable for applications such as dynamic RAMs. The entire process can be carried out in a single pump down and therefore contamination levels can be minimized.

BACKGROUND OF THE INVENTION I. Field of the Invention This invention relates to derrick rigs used for attaching drill tubing to or removing drill tubing from a drill string at a well head. II. Description of the Prior Art The conventional way of lengthening or shortening a drill string made up of interconnected pipe sections at a well head is by means of a derrick, i.e. a framework tower constructed over the well head and including a hoist for raising or lowering the drill string. Once the drill string has been raised or lowered by a distance corresponding to the length of one or more pipe sections, the drill string is clamped at the well head and either projecting pipe sections are removed (if the drill string is being shortened) or new pipe sections are added (if the drill string is being lengthened), and the process is repeated. This procedure requires an operator, usually referred to as a derrickman, to transfer the pipe sections between the drill string and a storage station for the pipe sections. This is inefficient and can be dangerous for the derrickman. Attempts have been made in the past to automate this procedure to avoid the need for a derrickman. However, these attempts have generally required an operation in which pipe sections have to be laid out on the ground, where the pipe couplings may be contaminated with mud or the like, and in which single pipe sections are handled individually. OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide a derrick assembly capable of conveying pipe sections automatically between a drill string and a storage rack for the pipe sections. Another object of the invention, at least in its preferred forms, is to provide such an assembly capable of handling interconnected double pipe sections. SUMMARY OF THE INVENTION According to the invention there is provided a derrick assembly for raising or lowering a drill string made of interconnected pipe sections, comprising: a derrick frame having lateral sidewalls and a base together defining an elongated channel having an open outer side opposite to said base; a rack positioned within said channel adjacent to one lateral sidewall thereof leaving part of said channel clear for manipulating said drill string, said rack comprising at least one element extending between said base and said open outer side for housing pipe sections therebetween substantially longitudinally aligned within said channel; a gantry extending across said open outer side of said channel, said gantry being movable longitudinally of said channel; and a pipe gripping unit supported by said gantry for selectively holding or releasing pipe sections, said gripping unit being movable on said gantry towards or away from said base and laterally between said sidewalls; whereby said pipe gripping unit may be manipulated on said gantry to transfer pipe sections between said rack and said clear part of said channel for attachment to or detachment from said drill string. The invention also relates to a racking assembly comprising the gantry and gripping unit as defined above. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a transporter vehicle at a slant well head, the transporter vehicle being provided with a derrick assembly according to a preferred form of the present invention to form a slant service rig; FIG. 2 is a rear elevation of the slant service rig of FIG. 1; FIG. 3 is a cross-section of the derrick assembly along the line III--III of FIG. 1; FIG. 4 is a top plan of the view of FIG. 3; FIG. 5 is a side elevation of the derrick assembly in the region of the cross-section of FIG. 3; FIGS. 6 and 7 are an end view and side view, respectively, of gripper elements; FIG. 8 is a view similar to FIG. 3 showing the unit in the stowed condition; FIGS. 9 to 11 are enlarged views of a gantry in isolation; FIGS. 12 to 14 are views in isolation of a carriage unit slidable on the gantry; and FIG. 15 is a schematic hydraulic circuit diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the accompanying drawings, FIGS. 1 and 2 show a slant service rig incorporating one form of a derrick assembly 10 according to the present invention, FIG. 3 is a cross-section of the assembly 10 taken on the line III--III of FIG. 1 and FIG. 4 is a plan view of the assembly 10 of FIG. 3. In the assembly 10, a derrick frame 11 is pivotally attached to a transporter vehicle 12 positioned at a slant well head 13 having a working floor 13A, the derrick frame 11 being aligned relative to the horizontal with the same slant angle as the well head. The illustrated frame 11 has an 84 foot clear working height so that it can accommodate double lengths of pipe sections and is preferably telescoped for easier transportation. With a 140,000 lb. load capacity, the derrick frame 11 can accommodate up to 7500 ft of stored tubing. The derrick frame 11 is pivoted to the desired position by hydraulic cylinders 14 and is held in place by adjustable supports (stiff legs) 15 which can be locked into various fixed positions by hydraulic latch pins 16 which engage holes 17. The derrick frame 11 is an open assembly of girders forming a base 18 (see FIG. 3) and lateral sidewalls 19 and 20, the outer side 21 of the derrick frame being open. The base and sidewalls together define an elongated channel having an open side opposite the base. The derrick frame incorporates a rack R in the channel formed by twelve upright dividers 22 extending from the base 18 towards the outer side 21 and running along the length of the storage section of the channel in the derrick frame and forming between them open-ended storage slots 23 for drilling pipe sections 24. If preferred, the dividers 22 need not be continuous and may instead be formed by aligned upright posts spaced at suitable intervals along the channel in the derrick frame 11. A rack floor RF is provided (see FIG. 2) to support the ends of the pipe section. The dividers 19 extend laterally from sidewall 20 only partially across the body of the derrick frame 11 leaving a clear channel part 25 between the final divider 22A and the sidewall 19 of the derrick frame 11. As can be seen most clearly from FIG. 2, in use the clear channel part 25 is aligned with the well head 13 so that a drill pipe section may be positioned in the clear channel while being added to or removed from the drill string at the well head. In fact, as mentioned earlier, the length of the derrick frame 11 is such that double sections of drill pipe 24 (i.e. two sections of normal length already attached together) may be stored in storage slots 23 or manipulated in clear channel part 25 by split blocks 26 (FIG. 3). As shown in FIGS. 3 and 4, a pipe racking assembly 27 is fixed across the open outer side 21 of the derrick frame 11, approximately midway along the length of the derrick frame, for the purpose of removing double pipe sections 24 from the storage slots 23 to the clear channel 25, and vice versa. The racking assembly 27 is slidably mounted on the outer ends of sidewalls 19 and 20 of the derrick frame 11 via roller units 28 and includes an open framework gantry 29 supporting a pipe gripping unit comprising a laterally movable carriage 30 and an elongated pipe boom 31, positioned beneath the carriage 30, extending longitudinally of the derrick frame 11 and carrying pipe gripping elements 32. Movements of the pipe boom 31 towards and away from the base 18 are controlled by a hydraulic cylinder 33 and guided by a pair of chrome guide posts 34 extending through collars 34A fixed to the movable carriage 30. The lateral position of the carriage 30, and consequently also the pipe boom 31, is controlled by a second hydraulic cylinder 35 and is guided on rails provided on the gantry, as will be explained more fully later. This allows the pipe boom 31 to be lowered to the bottom of any one of the storage slots 23, as shown in dotted lines at the right hand side of FIG. 3, to collect a pipe section 24 from the rack R, to raise it above the rack as shown in solid lines, to move it laterally to a position above the clear channel 25 as shown in dotted lines at the left hand side of FIG. 3 and then to lower the pipe section to a position 36 aligned with the longitudinal axis of the drill string for attachment to the drill string. The racking assembly can of course be operated in reverse to remove a pipe section from the drill string and to place the pipe section in any one of the slots 23 of the rack R. The racking assembly 27 is shown in side view in FIG. 5. Roller units 28 slidably support the pipe racking assembly 27 on each side of the derrick frame 11. The longitudinal position of the racking assembly on the derrick frame is controlled by a pair of hydraulic cylinders 37 attached to the sidewalls of the derrick frame. The entire racking assembly 27 can thus be moved along the derrick frame 11 by several feet (normally 12.5 feet) to the position indicated by dotted lines at the left hand side of FIG. 5 (e.g. the bottom of the derrick). This allows pipe sections (not shown in FIG. 5) to be moved longitudinally in the direction of the axis of the drill string so that attachment to and removal from the drill string may take place. The pipe boom 31 carries three gripping elements 32, two at each longitudinal end and one approximately centrally. These gripping elements are shown in more detail in FIGS. 6 and 7 which show a gripping element 32 at one extreme end of the boom 31, but the other gripping elements are essentially the same. Pipe boom 31 has a circular cross-section along most of its length but has "I" shaped sections 31A at the positions of gripping elements 32. The I-shaped sections have pairs of lugs 38 extending from each face near the top for receiving and pivotally retaining lugs 39 of operating cylinders 40. A pivot unit 41 extends from the lower edge 42 of the I-shaped section 31A and receives a pivot 43 for gripping jaws 44. The gripping jaws are pivotally attached to operating rods 45 extending from the lower ends of operating cylinders 40. Operation of hydraulic cylinders 40 causes gripping jaws 44 to rotate around pivot 43 towards or away from each other to grip or release a pipe section 24. Gripping elements 32 have a designed slip assembly to accommodate 203/8, 207/8, 301/2 and 401/2 inch tubing. This slip prevents the tubing from slipping through the grippers. It will be understood from the above description that the racking assembly 27 has the ability to move pipe sections 24 towards or away from the base 18 in the planes of the slots 23, sideways above the rack R to or from the clear channel part 25 and longitudinally of the derrick frame 11 while being securely supported at three widely spaced positions by gripping elements 32 attached to pipe boom 31 which can grip or release the pipe sections as desired. The racking assembly therefore provides a convenient and safe way of transferring pipe sections between a drill string and a pipe section storage station. FIG. 8 is a cross section similar to FIG. 3 showing the racking assembly 27 in the stowed condition for transportation. It will be seen that the gantry 29 has been lowered into the derrick frame 11 and the pipe boom 31, operating cylinder 33 and guide posts 34 have been rotated to a horizontal position to lie across the open outer side 21 of the derrick frame 11. This arrangement has the advantages that the projecting cylinder 33 and posts 34 are folded away and the gantry 29 is lowered into the frame 11 so that the rig 12 will have minimum overall height. Naturally, during transportation, the derrick frame 11 is lowered to the horizontal position on the vehicle 12 from the slant position shown in FIG. 1. The conversion of the racking assembly to the stowed condition shown in FIG. 8 is permitted by the design of the roller units 28 and the design of the movable carriage 30. The design details of these elements are described in more detail below. FIGS. 9, 10 and 11 are, respectively, a top view, a cross section along the line X--X of FIG. 9 and a side elevational view of the gantry 29 in isolation. The gantry consists of two transverse elements 61, four legs 63 and two longitudinal elements 64 connected together in the manner shown. The transverse elements 61 each have a small elongated rectangular rail 65 extending from an inner sidewall towards each other and these rails movably support the carriage 30 (see FIG. 13). The legs 63 each have a pair of holes 65 extending in the longitudinal direction of the derrick frame 11 at the bottom ends of the legs and a single hole 66 just below the attachment to the longitudinal elements 64. These holes are used to fix the gantry 29 in the roller units 28 either in the operating condition (holes 65) or in the stowed condition (holes 66). FIGS. 12, 13 and 14 are, respectively, a plan view, an end elevation and a side elevation of the carriage 30 which is movable carried on the rails 65 of the gantry 29. The carriage is in two parts 30A and 30B which are hingedly connected together by downwardly projecting lateral hinges 50. The two parts of the carriage 30A and 30B are held in the position shown in the drawings by locking element 51 which includes a pair of lugs 52 attached to the first part of the carriage 30A and a second lug 53 attached to the second part of the carriage 30B, the lugs having aligned holes receiving a removable locking bolt 54. Only after the bolt 54 has been removed can the two parts of the carriage move relative to each other around the hinges 50 from the operating position to the stowed position. The part 30B of the carriage includes collars 34A for receiving the guide posts 34 and a hole 56 for receiving an operating rod of cylinder 33 (the cylinder is mounted on carriage part 30B). Thus, when the part 30B pivots about the hinges 50, the operating cylinder 33 (not shown) and guide posts 34 (not shown) also pivot to the stowed position as shown in FIG. 8. When the gantry 29 is in the operating position, legs 60 are held in the roller units 28 by bolts extending through the pair of holes 65 and corresponding holes in the roller units 28. The bolt 54 is also in position through holes in the lugs 52,53 of the carriage 30 to lock the cylinder 33 and guide posts 34 in the upright position. When the equipment is to be stowed, first of all the pipe boom 31 is moved over the clear channel part 25 (see FIG. 3) and is lowered until it rests against a block track below blocks 26 welded to base 18 of the derrick frame 11. The cylinders are then pressurized until they take the weight of the gantry 29 and the bolts are removed from the pairs of holes 65 at the ends of the legs 63 of the gantry. The cylinder is then used to lower the gantry 29 to the stowed position and a bolt is placed in each of the holes 66 in the legs of the gantry to lock the gantry in place. The boom 31 is then raised to the upright position, the carriage 30 is moved as far to the left hand side as possible, bolt 54 is removed from the lugs 52, 53 and the cylinder 33 and guide posts 34 are pivoted hydraulically to the stowed position. The reverse procedure sets up the equipment for operation. It will be appreciated that the derrick assembly may be used to service a vertical well, in addition to a slant well as shown, merely by raising derrick frame 11 to the vertical position. The rack R may be designed with a small degree of slant relative to the derrick frame 11 (e.g. three degrees of slant) to prevent the pipes from falling out of the rack R when the derrick frame 11 is vertical. In the apparatus of the present invention, at least in the preferred forms, pipe sections (preferably double lengths) are conveniently stowed in the derrick frame itself and are manipulated entirely by power devices between the drill string and the storage station. The equipment is thus efficient and safe. A hydraulic control system for the derrick assembly of the invention is shown in FIG. 15. It includes a hydraulic pump 70 with an inlet from hydraulic fluid reservoir 71. The fluid outlet from the pump is supplied to the system via feed line 72 and the fluid returns to the reservoir via return line 73 through return flow filter 74. The control unit includes a directional valve 75 and four solenoid valves 76a, 76b, 76c and 76d. The solenoid valve 76a is used to actuate arm cylinder 33 and the flow circuitry includes a counterbalance valve 77. The solenoid valve 76b actuates horizontal carriage cylinder 35. The gripper cylinders 40 are actuated by solenoid valve 76c and the flow circuitry for the gripper cylinders includes an accumulator 78 and a check valve 79. The solenoid valve 76d is used to actuate the virtual carriage cylinders 37. The fluid circuitry for these cylinders includes a flow divider/combiner valve 81 and a pair of counterbalance valves 82. While preferred forms of the invention have been described in detail, it will be apparent to persons skilled in the art that various changes and modifications could be made without departing from the scope of the invention as defined by the following claims.

A derrick assembly capable of conveying pipe sections between a drill string and a rack for storing the pipe sections. The assembly includes a frame having lateral sidewalls and a base together defining an elongated channel having an open outer side opposite to the base. A rack for housing pipe sections is positioned within the channel adjacent to one lateral sidewall leaving part of the channel clear for manipulating the drill string. The rack is formed by a number of elements extending between the base and the open outer side for housing pipe sections oriented generally longitudinally within the channel. A gantry extends across the open outer side of the channel and is movable longitudinally of the channel. The gantry supports a pipe gripping unit for selectively gripping or releasing pipe sections capable of moving towards or away from the base and laterally between the sidewalls. The pipe gripping unit can thus convey pipe sections between the rack and the clear part of the channel by appropriate movements in the stated directions.

RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application Ser. No. (U.S.S.N.) 60/992,877, entitled “Composite Armor Material and Method of Manufacture”, filed on Dec. 6, 2007. The entire disclosure of U.S. Ser. No. 60/992,877 is incorporated herein by reference. FIELD OF THE DISCLOSURE [0002] This disclosure relates to composite armor materials and methods of manufacturing such a materials. Armor produced using the disclosed methods and composite armor materials can include one or more of the following advantages: a) an outer layer or strike face providing excellent hardness and toughness b) a middle or core layer that absorbs substantial compressive energy and substantially impedes pressure waves associated with ballistic impact, and c) an inner layer (i.e., a spall liner) having improved reinforcement to prevent ballistic penetration. Additional advantages afforded by the claimed material include resistance to chemical attack, a high strength-to-weight ratio, and easy production of a multitude of armor geometries. BACKGROUND [0003] Armor has been used throughout history as protective clothing or outer layer intended to prevent harm from projectiles. Today's advanced armor is a layered composite material. In general, modern composite armor includes three layers: (1) an outer region also known as a strike face that is intended to blunt and disrupt the impact of an incoming projectile and to distribute the resulting force, (2) a middle or core region designed to absorb energy and attenuate pressure waves, and (3) an inner region known as a spall liner to minimize and/or prevent complete penetration of the projectile or blast by-products. SUMMARY OF THE DISCLOSURE [0004] The present disclosure applies to materials used in armor (e.g., armored clothing/fabric, armored vehicles) and methods of manufacturing such materials. By employing deposition (e.g. electrodeposition) of laminate materials (e.g., nanolaminate materials, microlaminate materials), greater strength-to-weight ratios can be achieved as compared with conventional armor. In addition, the strike face of the disclosed material has excellent hardness and toughness, the core region can absorb substantial compressive energy and attenuate pressure waves, while the spall liner provides reinforcement to prevent ballistic or blast by-product penetration as compared to conventional armor. Methods described herein (e.g., electrodeposition) provide advantages including the ability to produce a multitude of armor geometries and the ability to create a cohesive layered material, i.e., a well-bonded layered material whose layers/regions work together to minimize damage from an impacting projectile. [0005] One aspect of the present disclosure is to provide a layered material that minimizes damage caused by an impacting projectile. The layered material includes a strike face region that blunts and disrupts the impacting projectile and distributes the force of impact over a comparatively large area; a core region designed to absorb energy from an impacting projectile and attenuate blast-induced pressure waves; and a spall liner region adapted to prevent penetration by-products of the impacting projectile. The strike face can include a compositionally or structurally modulated nanolaminate material that modulates between hard and tough constituent materials or phases. The core region can include a nano- or microlaminate material that reinforces a compliant phase material such as, for example, a polymer or foam. The spall liner can include a nano- or microlaminate reinforced long-range periodic material, such as fibrous material. [0006] In another aspect, embodiments described in the present disclosure are directed to composite armor material comprising a plurality of layers, wherein the plurality of layers comprises an electrodeposited modulated material including a modulation wavelength less than about 1000 microns. Such embodiments can include one or more of the following features. The composite armor material may comprise a porous substrate including an accessible interior void structure at least partially filled with the electrodeposited modulated material. The composite armor material may be compositionally modulated. In some embodiments, the composite armor material may be structurally modulated. [0007] Embodiments of this aspect of the disclosure can also include one or more of the following features. In some embodiments, the composite armor material can have a plurality of layers arranged to define a strike face region, a core region, and a spall liner region, where the strike face region provides toughness and hardness to distribute force of an impacting projectile, and the core region provides energy absorption to absorb energy from the impacting projectile, and the spall region provides strength to inhibit penetration of the armor material. The strike face region may comprise a periodic hard-tough transitions, wherein the periodic hard-tough transitions may be graded. In some embodiments, the strike face region comprises a laminated material. In some embodiments, the core region comprises a metal phase and a compliant phase, wherein the metal phase may comprise a laminated material, and the compliant phase may include a porous template, in which void regions of the porous template may be filled by a gas or liquid. In some embodiments, the compliant phase may include a low density solid, such as a polymer or a foam having a density of less than about 5 g/cc. In some embodiments, the spall liner region of the composite armor material may comprise fibers and a laminated material, wherein the fibers may be reinforced with a sheath formed of the laminated material, and the fibers may be disposed within a matrix of the laminated material. In other embodiments, the boundaries between regions of the plurality of layers in the composite armor material are graded. [0008] Another aspect of this disclosure is to provide a method for the manufacture of a composite armor material, wherein one or more of the regions within the material is produced through electrodeposition. For example, at least one of the strike face region, core region, and spall liner region is made using electrodeposition of nanolaminate or microlaminate materials. [0009] In another aspect, embodiments described herein are directed to methods of producing a composite armor material. The methods includes providing an electrolyte containing a metal; providing a porous substrate; immersing the porous substrate in the electrolyte; passing an electric current through the porous substrate so as to deposit the metal onto the porous substrate; and changing one or more plating parameters in predetermined durations between a first value, which is known to produce a material with one property, and a second value, known to produce a material with a second property, to form a portion of at least one of a strike face region, a core region, and a spall liner region. [0010] Embodiments of the above methods can also include one or more of the following features. The plating parameter of the method can include one or more of pH set point value of the electrolyte bath, electrolyte composition of the bath, applied plating current, applied plating voltage, and mass transfer rate. The plating parameter can be change, in some embodiments, according to one of a square wave, a triangle wave, and a sine wave. BRIEF DESCRIPTION OF THE DRAWINGS [0011] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosure. [0012] FIG. 1 is an illustration of a cross-sectional view of an electrodeposited armor. [0013] FIG. 2 is a an illustration of a cross-sectional view of a strike face region of the electrodeposited armor of FIG. 1 . [0014] FIG. 3A is a graph showing a waveform of iron content in a nickel-iron compositionally modulated electrodeposited material and FIG. 3B is a corresponding composition map. [0015] FIG. 4 is an illustration of several embodiments of a porous template. [0016] FIG. 5 a is a scanning electronmicrograph (SEM) image of a liquid nitrogen-chilled fracture surface of a metal nanolaminate deposited over a reticulated foam substrate at a magnification of 24×. FIG. 5 b is a SEM image of the same fracture surface at a magnification of 100×. FIG. 5 c is a SEM image of the same fracture surface at a magnification of 600×. [0017] FIG. 6 is an illustration of a cross-sectional view of a composite material utilized within a spall liner region of the composite armor of FIG. 1 . [0018] FIG. 7 is an illustration of a cross-sectional view of another composite material utilized within the spall liner region of the composite armor of FIG. 1 . [0019] FIG. 8 is an illustration of a cross-sectional view of an embodiment of an electrodeposited compositionally modulated material. [0020] FIG. 9 a is an illustration of a cross-sectional view of a porous substrate formed from a carbon fiber tow reinforced with an electrodeposited nanolaminated metal. FIGS. 9 b and 9 c are illustrations of another porous substrate reinforced with electrodeposited metal. Specifically, FIG. 9 b is an illustration of a reticulated foam including 6 struts and FIG. 9 c is a cross-sectional view of one of the struts showing the nanolaminated metal reinforcing the strut (substrate). [0021] FIG. 10 is an illustration of a cross-sectional view of a composite material. This composite material includes a consolidated porous substrate with a compositionally modulated electrodeposited material filling at least a portion of an open, accessible void structure of the porous substrate. [0022] FIG. 11 is an illustration of a cross-sectional view of the compositionally modulated material of FIG. 10 along one of the voids. [0023] FIG. 12 is an illustration of an electroplating cell including a working electrode attached to a porous substrate. [0024] FIGS. 13 a, 13 b, 13 c, 13 d, 13 e are graphs showing electrodeposition conditions and resulting compositional maps for the deposition conditions. FIG. 13 a is a plot of applied frequency to a working electrode in an electrochemical cell versus time. FIG. 13 b is a plot of applied amplitude to a working electrode in the electrochemical cell versus time. FIG. 13 c is a plot of applied current density to a working electrode in the electrochemical cell versus time. FIG. 13 d is an envisioned resulting deposit compositional map corresponding to the applied current density given in FIG. 13 c, that is for one frequency modulation cycle. FIG. 13 d is an envisioned compositional map corresponding to application of ten frequency modulation cycles of deposition. [0025] FIGS. 14 a - 14 c are illustrations of cross-sectional views of various embodiments of composite materials. FIG. 14 a is an illustration of a composite including an electrochemically infused particle bed having a particle distribution that gradually increases from the exterior surfaces of the composite into the center of the composite. FIGS. 14 b and 14 c are other illustrations of a composite including an electrochemically infused particle bed. In FIG. 14 b , the particles have a repeating size distribution. In FIG. 14 c the particles have a graded size distribution. [0026] FIGS. 15 a and 15 b are illustrations of two separate embodiments of a compositionally modulated material disposed within the void structure of four particles. [0027] FIG. 16 is an illustration of a cross-sectional view of an embodiment of a composite material including a nanostructured capping layer deposited on an exterior surface of a porous substrate. [0028] FIG. 17 is an illustration of a cross-sectional view of an embodiment of a consolidated, conductive porous substrate with a tailored filling of a compositionally modulated electrodeposited coating disposed within its accessible void structure. Deposition conditions for this embodiment have been tailored to not only vary a thickness of the coating throughout the depth of the consolidated conductive porous substrate, but also to cap or seal the composite with a dense compositionally modulated layer that closes off accessibility to the interior void structure. [0029] FIG. 18 is an illustration of a flow cell for electrodepositing a compositionally modulated material into a void structure of an electrically conductive porous substrate. [0030] FIG. 19 is an illustration of a flow cell for electrodepositing a compositionally modulated material into a void structure of an electrically non-conductive porous substrate. DETAILED DESCRIPTION [0031] Referring to the drawings, FIG. 1 illustrates one embodiment of an electrodeposited composite armor comprising 1) a hard strike face intended to a) blunt and disrupt impacting projectiles and b) distribute the force of impact over a comparatively large area; 2) an energy absorbing core designed to a) absorb additional energy from the impacting projectile and b) attenuate blast-induced pressure waves; and 3) a spall liner designed to prevent complete penetration by products of the impact event. One or more additional regions can be added to the embodiment of FIG. 1 . [0032] Features of the strike face ( 1 ) include both superior hardness and toughness, which can be achieved by the controlled placement of hard and tough constituent materials within the strike face volume. Periodic hard-tough transitions can serve to arrest crack growth and improve fracture toughness. [0033] Referring to FIG. 2 , the strike face, for example, may consist of a thick compositionally or structurally modulated material ( 4 ) with a modulation wavelength ( 5 ) varying between 1 and 1000 nm. The local hardness within the deposit can be controlled through the modulation wavelength, the grain size, and/or the composition/phase. Above a certain minimum, typically 2-20 nm, smaller modulation wavelengths produce stronger, harder deposits through Hall-Petch strengthening. Below this wavelength cutoff (e.g., less than about 2-20 nm), hardness and strength decrease with decreasing wavelength. Wavelength modulations therefore can impart modulations in the local hardness of the laminate. For example, it is believed that as the wavelength decreases from 1000 nm towards ˜2-20 nm, hardness and strength increases; once below the 2-20 nm range, it is believed that the strength and hardness begin to decrease. The same approach holds true with structurally modulated materials, such as materials that are modulated in grain size or phase. For example, in embodiments where the grain size is modulated, hardness peaks at a grain size of approximately 2-20 nm. For example, in alloy systems which exhibit phase transitions such as fcc→bcc at a given alloy composition, a comparatively ductile fcc alloy can be interposed between strong and hard bcc material to form the structurally (phase) modulated material. The strike face may also contain ceramic particles such as boron carbide, silicon carbide, silicon nitride, or alumina embedded within the electrodeposited metal matrix, which may itself be a compositionally modulated alloy as described above. Modulating the concentration of ceramic inclusions would provide additional hardness modulation, and would additionally function to abrade impacting projectiles ( 6 ). Hard regions ( 7 ) may therefore be characterized by of one or more of the following: 1-20 nm grains, 2-20 nm wavelengths, bcc phases, and ceramic particle-rich regions, while tough regions ( 8 ) include one or more of the following >20 nm grains or wavelengths, <2 nm grains or wavelengths, regions of low/no ceramic inclusions, and fcc phases. In all of the cases described above, an additional embodiment may include gradation of the transition between hard and tough regions, such that the interface is blurred and delamination impaired as shown in FIG. 3 . [0034] In some embodiments, such as illustrated in FIG. 4 , strike faces may be produced by electrodepositing a tough metal phase ( 9 ) through one or more hard ceramic templates ( 10 ; i.e., a substrate, a porous substrate) including, for example, perforated ceramic plates ( 10 a ) and/or arrays of ceramic tiles ( 10 b ). The metal phase may itself be nano- and/or micro-laminated. The ceramic template may be modified, either by surface functionalization or roughening, to optimize the adhesion between itself and the metal. [0035] The energy-absorbing material of the core layer ( 2 ) includes a minor volume fraction (<50%, e.g., 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%) metal phase reinforcing and/or binding an otherwise soft/compliant phase, which may include gases, liquids, or solids such as polymers or low density solids (e.g., <5 g/cc). An example of such a core material is a reticulated foam reinforced with a metal nano-/microlaminate coating ( 11 ) as shown in FIGS. 5 a, 5 b, and 5 c. Another embodiment may include polymeric or foam templates (porous templates), analogous to the ceramic templates described above in FIG. 4 ( 10 a, b ), which have been infiltrated with nano- or micro-laminated metal having the structures described in the paragraphs accompanying FIG. 2 above. The common feature of these core designs is their substantial compressive energy absorption and their impedance to pressure waves induced by blasts. Thus, a core region material has a compliant phase (e.g., a foam, or other porous material, which can include a compliant solid such as a polymer) having a form which absorbs energy (e.g., a foam, a bed of beads filled with a liquid or gas.) The core region also includes a metal phase that reinforces and or binds (e.g. encapsulates bed of beads, nanolaminate coating on exterior of foam) the compliant phase. [0036] The spall liner ( 3 ) component of the composite armor design comprises a strong reinforcing material with long range periodicity such as woven carbon fiber, woven S2 glass, or woven Kevlar. A representative block of spall liner material is shown as ( 12 ) in FIG. 6 below. FIG. 6 illustrates in cross-section a woven fibrous composite panel with a polymer matrix ( 14 ) for a single tow of reinforcing fiber ( 13 ). The exterior of this fibrous panel has been further reinforced with a nano-/microlaminated metal coating ( 15 ). In a variant ( 16 ) of the previous embodiment shown as FIG. 7 , the fibers themselves may be reinforced with a thin nanolaminated metal sheath ( 17 ) prior to polymer infusion. A further embodiment replaces the polymer matrix entirely with a nanolaminated metal, infused through a non-conductive woven fiber material (e.g. S2 glass, Kevlar) or conformally plated onto a conductive fiber material (e.g. graphite, metalized S2 glass, or metalized Kevlar). [0037] The nano- and/or microlaminated materials included in the strike face, core layer, and/or the spall liner can be produced by electrodeposition (electroplating) under controlled, time-varying conditions. These conditions include one or more of the following: applied current, applied voltage, rate of agitation, and concentration of one or more of the species within the electroplating bath (e.g., a bath including one or more of an electrodepositable species such as nickel, iron, copper, cobalt, gold, silver, zinc, or platinum). Nano- or microlaminations are defined here as spatial modulations, in the growth direction of the electrodeposited material, in structure (e.g. grain size, crystallographic orientation, phase), composition (e.g. alloy composition), or both. Nanolaminates include a modulation wavelength that is less than 1 micron—i.e., the modulation wavelength is nanoscale. (See International Patent Publication No. WO2007021980 for a further description of nanolaminate materials and electrodeposition of nanolaminate materials; WO2007021980 is herein incorporated by reference in its entirety.) Microlaminates include a modulation wavelength that is less than 1000 microns. Metal nano- or microlaminates can be applied over a variety of substrates (e.g., preforms). In some embodiments the substrate includes a porous preform such as a honeycomb, fiber cloth or batting (woven or nonwoven), a reticulated foam (see FIGS. 5 a, 5 b, 5 c and 9 b and 9 c ), or a tow of fibers (see FIG. 9 a ), most of which possess little structural integrity in their original form, and can therefore be shaped to the desired component geometry prior to electrodeposition. In addition, metal nano- or microlaminates can be deposited throughout a porous preform formed of an unconsolidated material (e.g., a bed of powder or beads) or through a porous preform created by perforated ceramic plates or tiles. Metal laminates can be deposited into the open, accessible interior void structure of a porous preform, as well as on an exterior surface of any preform (solid substrate or porous preform). Furthermore, plating conditions (i.e. parameters) can be controlled to effect both uniform nano- or microlaminate growth throughout the preform, as well as preferential growth and densification near the external surface of the porous preform. That is, deposition of the nano- or microlaminate material can be controlled such that the laminate's thickness increases throughout the porous preform (or at least a portion of the preform). In this fashion, all three layers ( 1 , 2 , and 3 ) of the armor can be produced in a single production run without removing the part from the plating tank. Methods and Materials [0038] In some embodiments, nano- and/or microlaminated materials included within the strike face, the core layer, and/or the spall liner can include compositionally or structurally modulated materials. The compositionally modulated or structurally modulated materials can be formed through the use of electrodeposition. Some exemplary electrodeposition techniques and materials are provided within this section entitled “Methods and Materials.” These techniques and materials are not meant to be exhaustive, but rather are merely illustrative of possible embodiments of the technology disclosed herein. [0039] The term “compositionally modulated” describes a material in which the chemical composition varies throughout at least one spatial coordinate, such as, for example, the material's depth. For example, in an electrochemical bath including a nickel-containing solution and an iron-containing solution, the resulting compositionally modulated electrodeposited material 20 ( FIG. 8 ) includes alloys having a chemical make-up according to Ni x Fe 1−x , where x is a function of applied current or voltage and mass transfer coefficient at the deposition surface. Thus, by controlling or modulating at least one of the mass flow of the bath solution or the applied current or voltage to electrodes, the chemical make-up of a deposited layer can be controlled and varied through its depth (i.e., growth direction). As a result, a compositionally modulated electrodeposited material, as illustrated by material 20 shown in FIG. 8 , may include several different alloys as illustrated by layers 30 , 32 , 34 , 36 , and 38 . [0040] A “structurally modulated material” is similar to a compositionally modulated material, except that in a structurally modulated material the structure (e.g., grain size, phase, crystallographic orientation, etc.) is modulated rather than the composition. The remainder of this section will describe compositionally modulated materials. However, the same techniques can be used to create structurally modulated materials as well. For example, electrodeposition variables such as the flow rate which affects the deposition rate can be manipulated to grow the deposited material with a finer or larger grain size. Similarly, the growth rate and constituents of the deposited material can be manipulated to control the phase of the electrodeposited material. [0041] Referring to FIG. 8 , layers 32 and 36 represent nickel-rich (x>0.5) deposits in a compositionally modulated laminate material, whereas layers 30 , 34 , and 38 represent iron-rich (x<0.5) deposits. While layers 32 and 36 are both nickel rich deposits, the value for x in each of layers 32 and 36 need not be the same. For example, the x value in layer 32 may be 0.7 whereas the x value in layer 36 may be 0.6. Likewise, the x values in layers 30 , 34 , and 38 can also vary or remain constant. In addition to the composition of the constituents (e.g., Ni and Fe) varying through the depth of the electrodeposited material 20 , a thickness of each of the layers 30 to 38 varies through the depth as well. FIG. 8 , while not to scale, illustrates the change or modulation in thickness that can be made through the layers 30 , 32 , 34 , 36 , and 38 . [0042] FIGS. 10 and 11 illustrate a different embodiment of a composite material 18 (e.g., a material included in one or more of layers 1 , 2 , or 3 of the armor in FIG. 1 ). In this embodiment, a porous substrate 19 is a consolidated porous body. That is, the porous substrate 19 in this embodiment is a unitary piece that includes a plurality of voids 25 that define an accessible, interior void structure. Examples of consolidated porous bodies include, foams, fabrics, meshes, fibrous panels, ceramic plates, ceramic titles, and partially sintered compacts. The compositionally modulated material 20 (a different embodiment than shown in FIG. 8 ) is electrodeposited throughout the accessible, interior void structure to form a coating along the walls of the porous substrate 19 defining the voids 25 . [0043] Referring to FIG. 11 , the compositionally modulated material 20 disposed within the plurality of voids 25 (as shown in FIG. 10 ) includes multiple alloys illustrated as distinct layers 31 , 33 , 35 , and 37 . As described above, the compositionally modulated material 20 is varied in both constituent concentration (i.e., to form the different alloy layers making up the material 20 ) and in thickness of the layers. In the embodiment shown in FIG. 11 , nickel-rich layers 33 and 37 further include a concentration of particles disposed therein, thereby forming particle-reinforced composite layers. As shown in FIG. 11 , layers 33 and 37 need not include the same concentration of particles, thereby allowing the compositionally modulated material 20 to be further tailored to provide optimal material properties. While not wishing to be bound by any particular theory, it is believed that increasing the concentration of the particles in a layer increases the hardness of that particular layer. The concentration of particles per layer can be controlled through modulating the flow rate of the bath during electrodeposition. The particles can have any shape, such as spherical particles, pyramidal particles, rectangular particles, or irregularly shaped particles. In addition, the particles can be of any length scale, such as for example, millimeter sized (e.g., 1 to 5 millimeter), micron-sized (e.g., 100 microns to 0.1 microns), nanometer sized (e.g., 100 nm to 1 nm). In some embodiments, 85% or more (e.g., 87%, 89%, 90%, 93%, 95%, 96%, 97%, 98%, 99%, 100%) of the nanosized particles have an average grain size within a range of 10 nm to 100 nm. In certain embodiments, 85% or more of the nanosized particles have an average grain size within a range of 20 nm to 50 nm, 30 nm to 50 nm, 10 nm to 30 nm, or 1 to 10 nm. Examples of some suitable particles include carbide particles, alumina particles, glass particles, polymer particles, silicon carbide fibers, and clay platelets. [0044] To form or deposit the compositionally modulated electrodeposited material 20 , the porous substrate 19 can be submerged into an electrochemical cell. Referring to FIG. 12 , an electrodeposition cell 50 , in one embodiment, includes a bath 55 of two or more of metal salts, a cathode (i.e., working electrode) 60 , an anode (i.e., a counter electrode) 65 , and a power supply (e.g. a potentiostat) 70 , which electrically connects and controls the applied current between the working and counter electrodes, 60 and 65 , respectively. The cell 50 can also include a reference electrode 75 to control the potential of the substrate relative to a fixed, known reference potential. In general, when an electrical current is passed through the cell 50 , an oxidation/reduction reaction involving the metal ions in the bath 55 occurs and the resulting product is deposited on the working electrode 60 . As shown in FIG. 12 , the porous substrate 19 is positioned in contact with the working electrode 60 . For example, in certain embodiments, the porous substrate is formed of a conductive material and functions as an extension of the working electrode 60 . As a result, the resulting product of the oxidation/reduction reaction deposits within the accessible interior void structure. In other embodiments, the porous substrate 19 is formed of a nonconductive material and thus, electrodeposition occurs at a junction between the working electrode 60 and the porous substrate 19 . [0045] In general, one of the advantages of the methods and resulting composite materials described in this disclosure is a wide range of choices of materials available for deposition into the interior void structure 25 of the porous preform 19 or on the exterior of a porous or solid preform. For example, salts of any transition metal can be used to form the bath 55 . Specifically, some preferred materials include salts of the following metals: nickel, iron, copper, cobalt, gold, silver, zinc, and platinum. In addition to the wide range of materials available, electrodeposition techniques have an additional advantage of easily modifiable processing conditions. For example, a ratio of the metal salts and other electrodepositable components, such as, for example, alumina particles, can be controlled by their concentration within the bath. Thus, it is possible to provide a bath that has a Ni:Fe ratio of 1:1, 2:1, 3:1, 5:1, 10:1 or 20:1 by increasing or decreasing the concentration of a Fe salt within the bath in comparison to the Ni salt prior to deposition. Such ratios can thus be achieved for any of the electrodepositable components. Where more than two electrodepositable components are provided, such ratios can be achieved as between any two of the components such that the overall ratios for all components will be that which is desired. For example, a bath with Ni, Fe and Cu salts could yield ratios of Ni:Fe of 1:2 and a Ni:Cu of 1:3, making the overall ratio of Ni:Fe:Cu 1:2:3. In addition, a bath with Ni salt and alumina particles could yield a ratio of Ni:Al 2 O 3 of 2:1, 2:1, 1:2, 3:1 or 1:3 by increasing or decreasing the concentration of particles within the bath. [0046] FIGS. 13A , 13 B, and 13 C illustrate applied conditions to an electrochemical cell, such as that illustrated as 50 in FIG. 12 , for depositing the compositionally modulated material 20 . FIG. 13D illustrates a resulting composition map for the applied conditions shown in FIGS. 13A , 13 B, and 13 C. FIG. 13C shows the current density over a period of 130 seconds applied to a working electrode (e.g., working electrode 60 in FIG. 12 ). The applied current drives the oxidation/reduction reaction at the electrode to deposit a material product having the form A x B 1−x , where A is a first bath constituent and B is a second bath constituent. While FIG. 13C illustrates a current density range of between −20 to −100 mA/cm 2 , other current density ranges are also possible for example, a current density range of between about −5 to −20 mA/cm 2 may be advantageous in some embodiments. [0047] Another way of tailoring the modulation of the compositions of the deposited alloys (A x B 1−x , where x varies) is with respect to a composition cycle. Referring to FIG. 13D , a composition cycle 80 defines the deposition of a pair of layers. The first layer of the composition cycles is A-rich and the second layer is B-rich. Each composition cycle has a wavelength. A value assigned to the wavelength is equal to the thickness of the two layers forming the composition cycle 80 . That is, the wavelength has a value that is equal to two times the thickness of one of the two layers forming the composition cycle (e.g., λ=10 nm, when thickness of Ni-rich layer within the composition cycle is equal to 5 nm). By including one or more composition cycles the deposited material is compositionally modulating. In an advantageous embodiment, the compositionally modulated electrodeposited material includes multiple composition cycles (e.g., 5 composition cycles, 10 composition cycles, 20 composition cycles, 50 composition cycles, 100 composition cycles, 1,000 composition cycles, 10,000 composition cycles, 100,000 composition cycles or more). [0048] The applied current density as shown in FIG. 13C is determined from an applied variation in frequency of the current per time ( FIG. 13A ) in combination with an applied variation in amplitude of the current per time ( FIG. 13B ). Referring to FIG. 13A , an applied frequency modulation, shown here as a triangle wave, effects the wavelength of the composition cycles. As shown by comparing FIGS. 13A and 13D , the wavelength of the composition cycles decreases as the frequency increases. While FIG. 13A illustrates this effect with an applied triangle wave, any waveform (i.e., a value that changes with time) may be applied to control or modulate the frequency and thus control or modulate the thickness/wavelengths of the deposited material. Examples of other waveforms that may be applied to tailor the changing thickness/wavelength of each of the deposited layers/composition cycles include sine waves, square waves, sawtooth waves, and any combination of these waveforms. The composition of the deposit (i.e., x value) can also be further modulated by varying the amplitude. FIG. 13B illustrates a sine wave modulation of the applied amplitude of the current applied to the working electrode. By changing the amplitude over time, the value of x varies over time such that not all of the Ni-rich layers have the same composition (nor do all the Fe-rich layers have the same composition). Referring to FIGS. 3A and 3B , in some embodiments, the value of x is modulated within each of the layers, such that the compositionally modulated electrodeposited material is graded to minimize or mask composition discontinuities. As a result of applying one or more of the above deposition conditions, the compositionally modulated electrodeposited material can be tailored to include layers that provide a wide range of material properties and enhancements. [0049] One such enhancement is an increase in hardness. Without wishing to be bound to any particular theory, it is believed that regions of nanolaminate material (i.e., regions in which all of the composition cycles have a wavelength less than about 200 nm and preferably less than about 80 nm) exhibit a hardness not achievable by the same materials at greater wavelengths. This hardness is believed to arise from an increase in the material's elastic modulus coefficient, and is known as the “supermodulus effect.” In certain embodiments, for example, the composite material 20 of FIG. 11 , the compositionally modulated electrodeposited material 20 is deposited to include one or more regions, which provide the composite material 18 with the supermodulus effect. That is, the compositionally modulated electrodeposited material 20 disposed within the void structure 25 of the porous substrate 19 or on an exterior surface of a solid or porous substrate includes one or more regions in which all of the composition cycles include wavelengths less than 200 nm, and preferably less than about 80 nm. In one embodiment, the wavelengths are less than about 70 nm. In another embodiment, the hardness of the composite material 18 is enhanced by including varying concentrations of particles (e.g., Al 2 O 3 , SiC, Si 3 N 4 ) within an electrodeposited metal. For example, by increasing the concentration of Al 2 O 3 particles dispersed within layers of an electrodeposited Ni metal, an increase in Vicker's Hardness from 240 VHN to 440 VHN is achievable. [0050] In some embodiments, the compositionally modulated electrodeposited material can include regions in which the composition cycles include wavelengths less than 200 nm (and thus which may exhibit the supermodulus effect) and also include regions in which some portion (e.g., at least or about: 1%, 2%, 5%, 7%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 92% 95%, 97%, 99% and 100%) of the composition cycles include wavelengths greater than 200 nm. The portion(s) of the composition cycles that include wavelengths greater than 200 nm could also be represented in ranges. For example, the composition cycles of one or more regions could include a number of wavelengths greater than 200 nm in a range of from 1-2%, 2-5%, 1-5%, 5-7%, 5-10%, 1-10%, 10-20%, 20-30%, 30-40%, 40-50%, 50-60%, 60-70%, 70-80%, 80-90%, 90-92%, 90-95%, 95-97%, 95-99%, 95-100%, 90-100%, 80-100%, etc., with the balance of the composition cycles being less than 200 nm in that region. Without wishing to be bound by any particular theory, it is believed that, as hardness increases, ductility decreases. As a result, in order to provide a composite material that is enhanced to include regions of increased hardness and regions of increased ductility, the compositionally modulated electrodeposited material, in some embodiments, can include one or more regions in which all of the composition cycles have a wavelength of about 200 nm or less including wavelengths less than 1 nanometer, one or more regions in which all of the composition cycles have a wavelength greater than 200 nm, and/or one or more regions in which a portion of the composition cycles have a wavelength of about 200 nm or less and a portion have a wavelength greater than 200 nm. Within each of those portions, the wavelengths also can be adjusted to be of a desired size or range of sizes. Thus, for example, the region(s) having composition cycles of a wavelength of about 200 nm or less can themselves have wavelengths that vary from region to region or even within a region. Thus, is some embodiments, one region may have composition cycles having a wavelength of from 80-150 nm and another region in which the wavelengths are less than 80 nm. In other embodiments, one region could have both composition cycles of from 80-150 nm and less than 80 nm. [0051] In certain embodiments, the compositionally modulated material can be tailored to minimize (e.g., prevent) delamination of its layers during use. For example, it is believed that when a projectile impacts a conventional laminated material, the resulting stress waves may cause delamination or debonding due to the presence of discontinuities. However, the compositionally modulated electrodeposited materials described herein can include a substantially continuous modulation of both its composition (i.e., x value) and wavelength such that discontinuities are minimized or eliminated, thereby preventing delamination. [0052] Referring to FIGS. 14A-14C , a different embodiment of a compositionally modulated material 20 is shown. In addition to compositionally modulating the electrodeposited material 20 to form the composite 18 , the porous substrate material 19 can also be made of a material that is modulated through its depth. For example, as shown in FIG. 14A , in one embodiment, the porous substrate 19 is formed of particles 22 that gradually increase in size from an exterior 100 of the compact to an interior 110 of the composite 18 . The particles in such embodiments can range from, e.g., 5 nm on the exterior 100 to 50 microns in the interior 110 , 5 nm on the exterior 100 to 10 microns in the interior 110 , 5 nm on the exterior to 1 micron in the interior 110 , 10 nm on the exterior 100 to 10 microns in the interior 110 , or from 10 nm on the exterior 100 to 1 micron in the interior. The differently sized particles 22 contribute to the material properties of the composite 18 . For example, smaller particles have a greater surface area energy per unit volume than larger particles of the same material. As a result, the porous substrate 19 can be tailored to provide additional advantageous material properties to different regions of the composite 18 . Referring to FIGS. 15B and 15C , the porous substrate 19 can have other particle arrangements to provide different material properties to the composite 18 . For example, in FIG. 15 B the particles have a repetitive size distribution and in FIG. 15C the particles have a graded distribution. [0053] FIGS. 15A and 15B show an enlarged cross-sectional view of the compositionally modulated electrodeposited material 20 disposed between four adjacent particles 22 of a porous substrate 19 . In FIG. 16A , the particles 22 forming the porous substrate 19 are non-conductive particles (e.g., alumina particles, glass particles). As a result of their non-conductivity, electrodeposition occurs between two electrodes disposed on either end of the porous substrate 19 and the compositionally modulated electrodeposited material 20 is deposited in a bottom-up fashion. Thus, the compositionally modulated electrodeposited material fills the entire void structure 25 between the four particles. In the embodiment shown in FIG. 15B , the particles 22 are electrically conductive. As a result, electrodeposition can occur within the conductive porous material to produce layers that are initiated at a particle/void interface 120 and grow inwards to fill at least a portion of the interior void structure 25 . [0054] As illustrated in the embodiments of FIG. 16 and FIG. 17 , in addition to electrodepositing into a porous preform, the compositionally modulated material 20 can also be deposited on the exterior surfaces 100 of the porous substrate 19 to form a nanolaminate or microlaminate coating. For example, after the accessible interior void structure 25 is at least partially filled in the case of an electrically conductive porous substrate or substantially filled in the case of a non-conductive porous substrate, an additional or capping layer 150 can be deposited onto the substrate to seal off the interior porous structure 25 as shown in FIG. 17 . [0055] In certain embodiments, the filling of the accessible interior void structure 25 is tailored such that the thickness of the compositionally modulating electrodeposited material 20 varies throughout the composite 18 . For example, FIG. 17 illustrates a composite material 18 formed of a porous conductive foam 19 and a Ni x Fe 1−x compositionally modulated material 20 . The thickness of the compositionally modulated material 20 continuously increases (i.e., thickens) from the interior portion 110 of the porous substrate 19 to the exterior 100 . To create this thickening, the current density during deposition is continuously increased. In addition to including the compositionally modulated material 20 disposed throughout the void structure 25 of the porous substrate 19 , a dense layer of the compositionally modulated material, referred to as the capping layer 150 is further applied to the exterior 100 of the substrate 19 to close off the accessible pore structure 25 . [0056] Methods of forming the composite 18 using electrodeposition can include the following steps: (1) forming a bath including at least two electrodepositable components, (2) connecting a preform, such as, for example the porous perform 19 , to the working electrode 60 , (3) inserting the preform, the working electrode 60 , and the counter electrode 65 into the bath 55 , and (4) applying a voltage or current to the working electrode 60 to drive electrodeposition. [0057] In general, in one embodiment, the voltage or current applied to the working electrode 60 varies over time so that the compositionally modulated material is electrodeposited into the voids 25 of the porous preform 19 . Thus, in some embodiments, the voltage or current is applied to the electrode 60 with a time varying frequency that oscillates in accordance with a triangle wave. In other embodiments, the voltage or current is applied to the electrode with a time varying frequency that oscillates in accordance with a sine wave, a square wave, a saw-tooth wave, or any other waveform, such as a combination of the foregoing waveforms. The voltage or current can be applied for one waveform cycle as shown in FIG. 13A , or preferably for two or more cycles (e.g., three cycles, five cycles, 10 cycles, 20 cycles). FIG. 13E shows the envisioned composition map for a 10 cycle deposit. [0058] In addition to controlling the voltage or current, other deposition conditions can also be monitored and varied to tailor the compositionally modulating material 20 . For example, it is believed that the pH of the bath has an effect upon the quality of the deposited material. Thus, in some embodiments, the pH of the bath is controlled during electrodeposition. For example, prior to deposition a pH set point (e.g., a pH of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14) or range (e.g., a pH of 1-2, 2-3, 3-4, 5-6, 6-7, 7-8, 8-9, 9-10, 10-11, 11-12, 12-13, or 13-14) is determined. During electrodeposition, the pH of the bath is monitored and if a difference from the set point is determined, pH altering chemicals, such as, for example, HCl, H 2 SO 4 , sulfamic acid, or NaOH, are added to the bath to return the bath to its pH set point. [0059] The concentration of the electrodepositable components in the bath can also be monitored and controlled. For example, concentration sensors can be positioned within the cell 50 to monitor the concentrations of the metal salts as well as any depositable particles within the bath. During electrodeposition of the compositionally modulated material 20 , the concentrations of the depositable components (e.g., metal salts, particles) can become depleted or at least decreased from a predetermined optimal level within the bath. As a result, the timeliness of the deposition of the compositionally modulated material 20 can be effected. Thus, by monitoring and replenishing the concentrations of the depositable components electrodeposition can be optimized. [0060] In certain embodiments, flow rate of the bath can be modulated or varied. As described above, both the applied current or voltage and the mass flow rate of the depositable components effects the x-value of the electrodeposit (e.g., Ni x Fe 1−x ). Thus, in some embodiments, the flow rate of the bath containing the depositable components is varied in addition to the applied voltage or current to produce the modulation in the value of x. In other embodiments, the applied voltage or current remains constant and the flow rate is varied to produce the modulation in the value of x. The flow rate of the bath can be increased or decreased by providing agitation, such as, for example, a magnetically-controlled mixer or by adding a pump to the cell 50 . By agitating the bath or by agitating the preform the mass transfer rate of the electrodeposited material is effected in that electrodepositable species may be more readily available for deposition thereby providing improved deposition conditions. [0061] FIGS. 18 and 19 illustrate embodiments of an electrochemical cell 50 that includes a pump 200 . In general, these cells 50 are referred to as flow cells because they force a bath solution through a porous substrate. Referring to FIG. 18 , the flow cell includes a porous working electrode 60 , which is also the porous electrically-conductive substrate 19 , and a porous counter electrode 65 . The working electrode 60 , the counter electrode 65 and the reference electrode 75 are in communication and are controlled by the potentiostat 70 . The bath fluid 55 including the depositable components is forced through the porous working electrode 60 (and thus the porous substrate 19 ) and the counter electrode 65 at a flow rate adjustable at the pump 200 . Thus, in certain embodiments, the flow rate of the pump 200 can be controlled in accordance with a triangle wave, square wave, sine wave, a saw tooth wave, or any other waveform, such that the flow rate can be modulated to produce the compositionally modulated material 20 . [0062] FIG. 19 illustrates another embodiment of a flow cell 50 for use with non-conductive porous substrates 19 . In this cell 50 , the working electrode 60 and the counter electrode 65 are disposed within a wall of the cell 50 and the bath fluid 55 is forced through the porous non-conductive substrate 19 . Electrodeposition occurs in a bottom-up fashion, that is, the deposition of material 20 proceeds from the working electrode 60 to the counter electrode 65 substantially filling the void structure along the way. [0063] The methods and composite materials described herein can be tailored to provide the unusual combination of strength, ductility, and low-density. For example, the porous substrate 19 forming the matrix of the composite material 18 can be formed of a light-weight ceramic material or can include a relatively large amount (e.g., 40% by volume, 50% by volume, 60% by volume) of accessible interior void space 25 . The compositionally modulated material 20 electrodeposited into the accessible, interior void space 25 can be tailored to provide strength at least in part through nanolaminate regions and ductility at least in part through micron or submicron sized laminated regions. [0064] In some embodiments, the composite material 18 is deposited on a solid preform (e.g., substrate) and/or a porous preform with closed porosity instead of a porous substrate with open porosity. In these embodiments, the composite material 18 is deposited on the exterior surface of the preform.

An armor material and method of manufacturing utilize nano- and/or microlaminate materials. In one embodiment, the armor material comprises a layered composite material including a strike face, a core layer, and a spall liner. The strike face achieves hardness and toughness by the controlled placement of hard and tough constituent materials through the use of nano- and/or microlaminate materials. The core layer achieves energy absorption through the use of nano- or microlaminated coated compliant materials. The spall liner provides reinforcement through the use of nano- or microlaminated fiber reinforced panels. In one embodiment, nano- and/or microlaminated materials can be manufactured through the use of electrodeposition techniques.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit of U.S. Provisional Patent Application No. 61/224,335, filed Jul. 9, 2009. All subject matter set forth in provisional application No. 61/224,335 is hereby incorporated by reference into the present application as if fully set forth herein. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to transport containers for safely moving flat screen display devices such as LCD, plasma, and LED flat display screens, interactive white boards, and like items that are large, flat shaped items which have sensitive surfaces that can easily be damaged if not well protected during transport from contact with surfaces inside the case. [0004] 2. Description of the Related Art [0005] Flat screen display devices such as liquid crystal display (LCD), plasma, and LED displays, interactive white boards, and the like have created a need for specialized transport containers to move these large, expensive items without damaging them. The screen surfaces are susceptible to damage if they are bumped or rubbed. Thus, rental companies, moving companies, conference centers, sound and video contractors, and performance staging companies are all in need of a light weight, stable, reusable transport case that can fully protect these delicate, flat shaped devices during transport. [0006] U.S. Pat. No. 7,466,372 B2 to Kim discloses a transport case for the liquid crystal cells that are ultimately manufactured into a display, but this case is not designed to accommodate and protect a large end product display. [0007] U.S. Pat. No. 7,140,508 to Kuhn discloses a flat shaped wooden shipping case for valuables such as framed paintings. This wooden case has a shipping holder to secure the painting within the case, and further utilizes vacuum insulation panels to protect the contents from fire and extreme temperature changes. The shipping holder disclosed in this patent encloses the entire perimeter of the painting. This case is not suitable for moving delicate flat screen items because it is too heavy, it does not provide a means to keep the item oriented vertically up, and it does not have a means to protect packaging materials from rubbing against the delicate screen surface. [0008] U.S. published application 20080272136 entitled Transport Case For Transport Of High Value Heavy Transport Goods discloses a transport case designed to transport very heavy items, such as printers, that must be removed from the case with a lift truck. It features a sliding object carrier at the base of the case that can move the item closer to the side of the case where the lift truck is situated. The lid of this case also comprises the sides of the case when closed so that when the lid is removed, there are no sides in the way of the lift truck when the case is opened. This case is not useful for flat screen items because lift trucks are not necessary for flat screen items, and the moving companies and conference center industries do not wish to use lift trucks to move flat screen items. Further, it does not incorporate the novel shape that is ideal for stabilizing flat screen items in an upright orientation, and the design features that can protect a large screen area from being touched. SUMMARY OF THE INVENTION [0009] It is an object of the present invention to achieve a transport case for moving large, delicate, valuable flat screen items that is lightweight so it is manageable, and shaped to accommodate large, flat screen items and keep them in their vertical, upright position throughout the moving process. [0010] It is further an object to achieve a case that protects the flat screen item from the impact of any bumps by suspending the item in shock absorbing cushion away from the rigid interior surfaces of the case. [0011] It is further an object to achieve a case that protects the delicate screen surface of the item to be moved from rubbing or contacting any cushioning, packaging, or assemblies designed to hold the item within the case. [0012] It is further an object to achieve a case that incorporates rollers at the base to further stabilize the case in an upright position and to provide for easy movement of the large case. [0013] It is further an object to incorporate useful handles to facilitate the lifting and moving of a large case and lid. [0014] It is further an object to incorporate lid securing straps. [0015] In one preferred embodiment, a transport case for moving large, flat screen devices includes a base and a mating lid. The lid is configured such that the lower portion slides over the corresponding top portion of the base to form a fully enclosed container. The base and lid are shaped such that the resultant case has a small depth compared to its height and width (i.e. a flat screen shape), to accommodate large, flat screen items. The case is wider at the lateral ends to provide a stable surface to keep the case in an upright orientation and prevent it from tipping over. The lower portion of the lid that overlaps with the top portion of the base at the widened lateral ends incorporates a horizontal shelf that rests on the corresponding top vertical edge of the base to hold the lid in suspension above the item to be transported. The wider base also serves to accommodate the end supports of a cradle system that keeps the item to be transported in cushioned suspension away from the interior sides of the case. The cradle system opening is adjustable to ensure that various sized items can be securely held within the case without any part of the cradle holding assembly touching the delicate flat screen area of the item to be transported. The case is made of lightweight plastic that is reinforced to ensure the sides do not collapse onto and touch the item inside without adding any appreciable weight to the case. Wheels, handles, and straps to secure the lid over the base can be added for additional convenience and security. BRIEF DESCRIPTION OF THE DRAWINGS [0016] There are shown in the drawings certain exemplary embodiments of the invention as presently preferred. It should be understood that the invention is not limited to the embodiments disclosed as examples, and is capable of variation within the scope of the appended claims. In the drawings, [0017] FIG. 1 is an exploded perspective view of an embodiment of the present invention with the lid separated from the base, [0018] FIG. 2 is a perspective view of an embodiment of the present invention with the lid closed over the base, [0019] FIG. 3 is an exploded perspective view of an embodiment of the present invention showing the cradle assembly of the base, [0020] FIG. 4 is an exploded perspective view of an embodiment of the present invention showing the reinforced channels of the base, and [0021] FIG. 5 is a cross sectional front view of an embodiment of the present invention with the lid closed over the base. DETAILED DESCRIPTION OF THE INVENTION [0022] Referring to FIGS. 1-5 , flat display transport cases according to embodiments of the present invention are now described. [0023] FIG. 1 is an exploded view of an embodiment of the invention with the lid separated from the base. The case 1 comprises a base 2 and a mating lid 3 . The base 2 has a bottom 4 , an opening at the top 5 , and a plurality of sides 6 extending upward from the bottom 4 . The lid 3 comprises a top 7 , an opening at the bottom 8 (opening not visible), and a plurality of sides 9 extending downward from the top 7 . [0024] The base 2 and the lid 3 are cooperatively shaped, with the opening 8 at the bottom of the lid 3 having a larger perimeter than the opening 5 at the top of the base 2 , so that the lid 3 can slide over the base 2 in an overlapping fashion, creating a fully enclosed storage compartment inside. FIG. 2 depicts an embodiment of the invention with the lid 3 closed over the base 2 . The lid 3 and the base 2 are cooperatively shaped such that the overlapping portion of the lid 10 slides over the corresponding top portion of the base 11 (hereinafter “nested portion of the base”), which is not visible in FIG. 2 because it is nested under the overlapping portion of the lid 10 . [0025] The base 2 and lid 3 are sized and shaped to cooperatively form a case 1 that accommodates a large, flat item in a vertical orientation. Thus, in the top up orientation depicted in FIG. 1 and FIG. 2 , the resulting case has a relatively thin depth as compared to its height and width. [0026] Referring to FIG. 1 , it can be seen that the depth of the base widens at both lateral ends 12 as compared to the middle 13 . The overlapping portion of the lid 10 correspondingly widens at the lateral ends. This unique shape provides a stable base to prevent the case 1 from tipping over on its side. This unique shape simultaneously creates a horizontal lid surface barrier 14 that prevents the lid 3 from resting on the top of the item to be transported. Thus, in the closed position, the lid 3 is prevented from resting on the top of the item to be transported, and instead, rests upon the vertical top edges of the base 35 that correspond to the horizontal lid surface barriers 14 . This unique shape also perfectly accommodates the cradle assembly that is installed into the interior bottom 4 of the base 2 , described further herein. [0027] The case 1 of the disclosed embodiments is fabricated of polyethylene plastic that is rotationally molded as a single piece, and is then divided into nested base 2 and overlapping lid 3 by cutting out a thin, transverse slice at the location that will become the mating edges of the base 2 and lid 3 . Rotational molding is a process known in the art for economically producing precision shaped plastic structures of uniform thickness. It produces molded plastic that is approximately 0.150 inches thick, resulting in a surprisingly light and manageable case given its size. Using a single mold as opposed to two molds results in less wasted plastic. [0028] Although thin molded plastic has the advantage of being light, durable, and low cost, it would not be ideal for fully protecting broad screen items such as large plasma displays without some reinforcement. The challenge is providing the reinforcement without appreciably increasing the overall weight of the case. Thus, in order to prevent the sides from collapsing in and possibly touching the delicate screen of the item inside, the inventors herein devised a way to reinforce the broad sides 17 of the front and back of the case (labeled on FIG. 2 and FIG. 4 ) without adding substantially to the weight of the case 1 . [0029] More specifically, in the disclosed embodiments, reinforcing channels 15 are molded into the base 2 and lid 3 as shown in FIG. 1 . The channels 15 are designed to receive metal braces 16 (depicted in FIG. 4 ) that are riveted to the interior of the channel, or attached therein by any suitable means. FIG. 4 is an exploded view that depicts an advantageous arrangement of reinforcing channels 15 for the base 2 . This embodiment utilizes two channels 15 that wrap around the bottom 4 and receive the braces 16 as depicted. This advantageous arrangement holds the central portion of the broad sides of the base 17 rigidly away from the contents of the case. No bracing is utilized at the lateral ends 12 of the base 2 because the cradle assembly end supports 20 (discussed further herein) provide the needed reinforcement at the lateral ends 12 . [0030] Corresponding channels 15 are incorporated into the lid 3 as depicted in FIG. 1 and FIG. 2 . Since the height of the lid 3 is not as great as the height of the base 2 , it is not necessary to wrap the channels around the top of the lid 7 to prevent the middle sides 17 of the lid 3 from collapsing and touching the item within the case. Instead, the lid 3 of FIG. 1 has an array of molded in ribs 18 to increase the rigidity of the top without adding the weight of metal braces. [0031] Aluminum is a useful brace material in that it is sufficiently rigid, yet light and resistant to corrosion. This novel process of utilizing the strategic placement of reinforcement channels only where needed, in combination with other case structures, allows the case to remain very light weight, yet rigid enough in critical locations to fully protect the contents from contact. [0032] Upon reading this disclosure, those skilled in the art may recognize other suitable materials and possible channel arrangements for utilizing lightweight materials in conjunction with bracing channels to practice the disclosed invention. The above disclosure is intended to fully disclose the invention, including preferred embodiments, and is not intended to limit the scope of the claims to the exact materials or channel layouts disclosed herein. The invention may be practiced with other suitable materials and may be practiced with or without reinforcing channels. [0033] The base 2 further comprises a cradle assembly to hold the item to be transported in cushioned suspension above the interior of the bottom of the base 4 . FIG. 3 is an exploded view of the base 2 that depicts a cradle assembly in accordance with the present invention. The cradle assembly is comprised of two cushioned end supports 20 , and two middle cushions 21 . The end supports 20 are separately molded polyethylene plastic in the disclosed embodiment. They are comprised of a bottom 22 , and three sides 23 . The top 24 and the fourth vertical side 25 are left open to receive and hold the item to be transported. [0034] The end supports 20 are secured to the interior bottom and sides of the base 2 (not fully depicted) by rivets or any other suitable means. The interior bottom 4 of the base 2 may be formed with protrusions (not depicted) to guide the proper alignment of the end supports 20 onto the interior bottom 4 of the base 2 during assembly. To provide a fully cushioned cradle, the disclosed end supports 20 can be interiorly lined on all surfaces ( 22 and 23 ) with a type of molded foam known in the art as closed cell polyethylene foam 26 . The molded foam lining 26 can be permanently adhered to the end supports with a pressure sensitive adhesive that is known in the art to be suitable for this use. [0035] Additional strips of adhesive backed molded foam 27 can be adhered to the foam lining 26 to adjust the size of the end support opening (defined by the open top 24 and the open fourth vertical side 25 ). The exploded view of FIG. 3 shows how wider strips 27 a can be used at the lateral ends to shorten the depth of the end support opening, and narrower strips 27 b can used to adjust the width of the end support opening at precisely selected locations to allow the foam 27 b to touch only the frame of the item to be transported and not touch the delicate screen area. These additional strips of foam 27 can either be permanently attached, such as with pressure sensitive adhesive, or they can be removably attached, such as with Velcro, to allow custom adjustments to a single case 1 for a variety of flat screen items. [0036] The two middle cushions 21 can be fabricated of the same foam in the shape depicted in FIG. 3 . They can be permanently adhered to the interior bottom 4 of the base 2 , spaced in a roughly equidistant manner between the two end supports 20 . The middle cushions 21 are shaped to support the bottom edge of the item to be transported, and to work in unison with the end supports 20 to support the item to be transported in cushioned suspension above the interior bottom 4 of the case. FIG. 5 is a cross sectional view of a closed case that depicts the cradle assembly installed into the bottom of the base 4 . This embodiment also includes lid foam cushions 28 on the interior of the top 7 of the lid 3 . [0037] It can be seen from FIG. 5 how the bottom of the item to be transported (item to be transported not depicted) would rest on horizontal foam surfaces 26 and 21 in suspension above the rigid interior bottom of the base 4 . The vertical sides 23 (see FIG. 3 ) of the end supports 20 hold the corresponding vertical sides of the item to be transported firmly in place. The foam lining 26 of the vertical sides provides cushioning from impacts, and the custom foam strips 27 reduce the depth and width of the end support opening to snuggly hold the frame of the item to be transported without touching the delicate screen area. See also FIG. 1 for a view of the tops of the end supports 20 with associated cushioning ( 26 , 27 a, 27 b ). [0038] Those skilled in the art will recognize and appreciate that a cradle assembly in accordance with this invention can be fabricated of different materials and shapes. The detail provided above is intended to provide a full and complete disclosure including preferred embodiments, and is not intended to limit the scope of the claims to the specific cradle assembly embodiments disclosed above. [0039] To enhance the mobility of the case 1 , rolling mechanisms 29 (labeled in FIG. 2 ) can be attached to the exterior bottom of the base 4 in any suitable fashion known in the art. The disclosed embodiments utilize four caster wheels 29 (three are visible), two at each lateral end. The casters 29 are bolted to the exterior bottom 4 of the base 2 in standard fashion. For enhanced directional control while moving the case 1 , the disclosed embodiments utilize two swiveling casters on one end (the forward end during movement), and two non-swiveling casters on the other end. [0040] The above arrangement of rolling mechanisms 29 are preferred for enhanced mobility and directional control, but those skilled in the art will recognize that any suitable number, orientation, and type of rolling mechanisms, or no rolling mechanisms at all, can be utilized to practice the invention. [0041] The FIG. 2 embodiment includes two straps 30 to secure the lid 3 to the base 2 . The straps may be fabricated of heavy duty 1.5″ nylon web. They can be permanently secured to the front of the base at any suitable location (attachment point not shown), and wrap around the bottom of the base 4 being securely buckled at the top of the lid 7 (buckles not depicted). Camphered edges 31 as shown in FIG. 2 can be utilized to prevent gaps between the straps 30 and the exterior bottom of the base 4 . In the disclosed embodiment, the straps 30 completely encircle the closed case 1 . It should be appreciated that the invention can be practiced without straps 30 , or with any variety of lid securing arrangements or devices known in the art. [0042] The case 1 of the present invention can be further equipped with a variety of handles. A useful arrangement is as depicted in FIG. 1 and FIG. 2 . The lid 3 is equipped with two lift bars 32 , one at each end, to facilitate lifting the lid 3 on and off the base 2 . The lift bars 32 can be fabricated with annodized aluminum tubing, or any other suitable handle type known in the art. A corresponding handle recess 33 is useful to allow plenty of room for a hand to grasp the bar 32 . The base 2 has two molded in end lift handles 34 , one on each end, to facilitate lifting the base 2 either alone, or with the lid 3 installed as needed. ( FIG. 5 depicts lift handles in cross sectional front view.) [0043] It will be appreciated that many varieties and arrangements of handles can be utilized within the scope of the invention, and that the invention is not limited to any particular handle arrangements. Handles are not necessary to practice the invention. [0044] The closed case embodiment of FIG. 2 has the following approximate dimensions: 35 inches high, 54 inches wide, 16 inches deep at the widened depth, and 10 inches deep elsewhere. These dimensions are useful to accommodate the variety of sizes of large flat screen display devices that are prevalent in the market at the time of this application. [0045] The above disclosure is intended to fully disclose the invention including preferred embodiments. Modifications and variations of the present invention that would be obvious to a person of ordinary skill in the art are deemed to be within the scope of the present invention. For instance, those skilled in the art will appreciate that the invention can be practiced with a variety of lid and base arrangements, and the nested arrangement that incorporates the shelf to hold the lid above the item to be transported are not the only lid and base arrangements that can be used to practice the invention.

A case for moving flat screen displays (plasma lcd and led), interactive white boards, digital signage and the like, comprising: a base and a mating lid; said base and said mating lid forming a fully enclosed storage compartment when fitted together; said base and said mating lid shaped to form a case that has a small depth compared to its height and width to create a storage compartment that is suitably shaped to accommodate a flat shaped item in a vertical orientation; said base having lateral ends that are wider in relation to the middle to create a stable base for the case; said base further comprising a cradle assembly to hold the item to be transported in cushioned suspension above the bottom surface of said base.

[0001] This is a Continuation-in-Part of Application Ser. No. 60/145,568, filed Jul. 26, 1999. BACKGROUND OF THE INVENTION [0002] The present invention relates to combination drug therapy for the treatment of Gaucher's disease and other glycolipid storage diseases. [0003] Gaucher's disease is a glycolytic storage disease caused by a genetic deficiency in activity of the catabolic enzyme beta-glucocerebrosidase. Beutler, Proc. Natl. Acad. Sci. USA. 90, 5384-5390 (1993). Manifestations of this disease are impaired hematopoiesis, bone fractures, a thinning of the bone cortex and massive enlargement of the spleen and liver. [0004] In recent years, several therapies have been proposed for the treatment of Gaucher's disease. An early therapeutic approach involved replacement of the deficient enzyme. See, for example, Dale and Beutler, Proc. Natl. Acad. Sci. USA 73, 4672-4674 (1976); Beutler et al., Blood 78, 1183-1189 (1991); and Beutler, Science 256, 794-799 (1992). [0005] Leading commercial products for enzyme replacement are CEREDASE (glucocerebrosidase), which is derived from human placental tissues, and CEREZYME (recombinant human glucocerebrosidase), both of which are produced by Genzyme Corp. See, for example, U.S. Pat. Nos. 3,910,822; 5,236,838; and 5,549,892. See also U.S. Pat. Nos. 5,879,680 and 6,074,684 on cloned DNA for synthesizing human glucocerebrosidase. [0006] Conjugates of the glucocerebrosidase enzyme with polyethylene glycol (PEG) have also been advanced by Enzon Inc. for treatment of Gaucher's disease. See, for example, U.S. Pat. Nos. 5,705,153 and 5,620,884. [0007] Still another approach for treatment of the disease is gene therapy, which involves an ex vivo gene transfer protocol. See, for example, U.S. Pat. No. 5,911,983. [0008] Another recent approach involves administration of the totally synthetic drugs, N-butyldeoxynojirimycin and N-butyldeoxygalactonojirimycin, as described, respectively, by Platt et al., J. Biol. Chem. 269, 8362-8365 (1994); Id. 269, 27108-27114 (1994). See also, U.S. Pat. Nos. 5,472,969; 5,786,368; 5,798,366; and 5,801,185. [0009] N-butyldeoxynojirimycin (N-butyl-DNJ) and related N-alkyl derivatives of DNJ are known inhibitors of the N-linked oligosaccharide processing enzymes, α-glucosidase I and II. Saunier et al., J. Biol. Chem. 257, 14155-14161 (1982); Elbein, Ann. Rev. Biochem. 56, 497-534 (1987). As glucose analogs, they also have potential to inhibit glycosyltransferases. Newbrun et al., Arch. Oral Biol. 28, 516-536 (1983); Wang et al., Tetrahedron Lett. 34, 403-406 (1993). Their inhibitory activity against the glycosidases has led to the development of these compounds as antihyperglycemic agents and as antiviral agents. See, e.g., PCT Int'l. Appln. WO 87/030903 and U.S. Pat. Nos. 4,065,562; 4,182,767; 4,533,668; 4,639,436; 5,011,829; 5,030,638; and 5,264,356. [0010] In particular, N-butyl-DNJ has been developed as an inhibitor of human immunodeficiency virus (HIV) as described by Fleet et al., FEBS Lett. 237, 128-132 (1988), and by Karpas et al., Proc. Nat'l. Acad. Sci. USA 85, 9229-9233 (1988), U.S. Pat. No. 4,849,430; and as an inhibitor of hepatitis B virus (HBV) as described by Block et al., Proc. Natl. Acad. Sci. USA 91, 2235-2239 (1994), PCT Int'l. Appln. WO 95/19172 and U.S. Pat. No. 6,037,351. BRIEF DESCRIPTION OF THE INVENTION [0011] In accordance with the present invention, a novel method and composition is provided for the treatment of a patient affected with Gaucher's disease or other such glycolipid storage diseases. The method of the invention comprises administering to said patient a therapeutically effective amount of both a N-alkyl derivative of 1,5-dideoxy-1,5-imino-D-glucitol having from about two to about 20 carbon atoms in the alkyl chain and a glucocerebrosidase enzyme. The N-alkyl substituent can be a short-chain alkyl group such as, e.g., ethyl, butyl or hexyl, or a long-chain alkyl group such as, e.g, nonyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl and eicosyl. [0012] A therapeutically effective amount is meant an amount effective in alleviating or inhibiting Gaucher's disease or other such glycolipid storage diseases in said patient. The glucocerebrosidase provides enzyme replacement for non-breakdown of glucocerebroside and the N-alkyl-DNJ jointly provides glycolipid inhibitory action. By use of the combination drug therapy of the invention, the medical benefits of both types of drugs should accrue to the patient with reduced amounts of either or both drugs than otherwise necessary to obtain equivalent or enhanced therapeutic results. That is, an additive or synergistic effect can reduce the frequency of the administration of the glucocerebrosidase enzyme and lower the dose of the long-chain N-alkyl-DNJ otherwise required for monotherapy of the disease. [0013] The alkyl group in the short-chain N-alkyl-DNJ compounds preferably contains four to six carbon atoms (e.g., butyl or hexyl). A most preferred compound is N-butyl-1,5-dideoxy-1,5-imino-D-glucitol, also known as the N-butyl derivative of deoxynojirimycin (DNJ), which also is abbreviated herein as N-butyl-DNJ. [0014] The alkyl group in the long-chain N-alkyl-DNJ compounds preferably contains nine to ten carbon atoms (i.e., nonyl and decyl). A most preferred compound is N-nonyl-1,5-dideoxy-1,5-imino-D-glucitol, also known as the N-nonyl derivative of deoxynojirimycin (DNJ), which also is abbreviated herein as N-nonyl-DNJ. [0015] In the field of general organic chemistry, the long-chain alkyl groups are known to provide more hydrophobic properties to compounds than are the short-chain alkyl groups. That is, solubility with water decreases with increase in chain length and decrease in temperature. For example, at 46° C., caproic acid (short-chain hexyl group) dissolves 10% by weight of water, whereas stearic acid (long-chain octadecyl group) dissolves only 0.92% even at the higher temperature of 69° C. Bailey's Industrial Oil and Fat Products, ed. Daniel Swern, 3d ed. 1964, p. 126. [0016] The long-chain N-alkyl derivatives of DNJ are known amino-sugar compounds. They were originally described as members of a group of short-chain and long-chain N-alkyl derivatives of DNJ having both glucosidase I inhibitory activity and antiviral activity, although no data on the long-chain N-alkyl derivatives was disclosed. See, e.g., DE 3,737,523, EP 315,017 and U.S. Pat. Nos. 4,260,622; 4,639,436; and 5,051,407. [0017] In another early study, although N-alkylation of the base DNJ reduced the concentration required for 50% inhibition of glucosidase I, the inhibitory activity was reduced as the length of the N-alkyl chain was increased from N-methyl to N-decyl according to Schweden et al., Arch. Biochem. Biophys. 248, 335-340, at 338 (1986). [0018] As far as the antiviral activity of the amino-sugar compounds against any particular virus is concerned, the activity of any specific analog cannot be predicted in advance. For example, in biologic tests for inhibitory activity against the human immunodeficiency virus (HIV), slight changes in the structure of the N-substituent were shown to have pronounced effects upon the antiviral profile as reported by Fleet et al., FEBS Lett. 237, 128-132 (1988). As disclosed in U.S. Pat. No. 4,849,430, the N-butyl derivative of DNJ was unexpectedly found to be more than two log orders more effective as an inhibitor of HIV than the N-methyl analog and three log orders more effective than the N-ethyl analog. [0019] In another study of N-alkyl derivatives of DNJ for activity against glycolipid biosynthesis, the N-hexyl derivative of DNJ required a dose of 0.2 mg/ml, whereas the corresponding N-butyl analog required a dose of only 0.01-0.1. On the other hand, the N-methyl analog was inactive. Thus, it was believed that effective carbon chain length of the N-alkyl group for this activity ranged from 2 to 8 according to U.S. Pat. No. 5,472,969. No disclosure was made therein concerning the N-nonyl or other long-chain N-alkyl derivatives of DNJ. [0020] N-nonyl-DNJ has been reported to be effective as an inhibitor of the Hepatitis B virus (HBV) based on inhibition of alpha-glucosidases in the cellular endoplasmic reticulum (ER) according to Block et al., Nature Medicine 4(5) 610-614 (1998). [0021] The effectiveness of the long-chain N-alkyl derivatives of DNJ in the method of the invention for treatment of Gaucher's disease and other such glycolipid storage diseases is illustratively demonstrated herein by inhibitory activity of N-nonyl and N-decyl DNJs against glycolipid biosynthesis in Chinese hamster ovary (CHO) cells and human myeloid (HL-60) cells. [0022] CHO cells are well-known glycoprotein-secreting mammalian cells. A typical CHO cell line is CHO-K1 which is available to the public from the American Type Culture Collection, Bethesda, Md., under accession number ATCC CCL 61. [0023] HL-60 cells are human promyelocytic cells described by Collins et al., Nature 270, 347-349 (1977). They are also readily available from the American Type Culture Collection under accession number ATCC CCL 240. [0024] Effective activity of N-nonyl-DNJ also is further illustratively demonstrated herein in conventional bovine kidney cells (e.g., MDBK, ATCC CCL 22) and hepatoma cells (e.g., HepG2, ATCC HB 8065). [0025] The unpredictability of the N-nonyl-DNJ against glycolipid biosynthesis is demonstrated herein by its inhibitory activity in the foregoing two cell lines. The N-nonyl-DNJ was unexpectedly found to be from about ten- to about twenty-fold better in the CHO cells and about four hundred times better in the HL-60 cells than N-butyl-DNJ at equivalent concentrations. The N-decyl-DNJ was demonstrated to be an effective inhibitor in HL-60 cells at 50 times lower concentrations than N-butyl-DNJ. These results were further unexpected in view of the increased hydrophobic nature of the long-chain N-alkyl derivatives of DNJ. [0026] The N-nonyl-DNJ also exhibits a more dramatic difference than N-butyl-DNJ in uptake which permits its use at a substantially lower level. In tests of organ distribution, the N-nonyl-DNJ was taken up five times better into the brain than N-butyl-DNJ. Thus, the N-nonyl-DNJ is believed to be a substantially better compound than N-butyl-DNJ for treating glycolipid storage disorders which involve the non-systemic side. [0027] N-nonyl-DNJ and N-decyl-DNJ can be conveniently prepared by the N-nonylation or N-decylation, respectively, of 1,5-dideoxy-1,5-imino-D-glucitol (DNJ) by methods analogous to the N-butylation of DNJ as described in Example 2 of U.S. Pat. No. 4,639,436 by substituting an equivalent amount of n-nonylaldehyde or n-decylaldehyde for n-butylaldehyde. The starting materials are readily available from many commercial sources. For example, DNJ is available from Sigma, St. Louis, Mo., whereas n-nonylaldehyde, also known as 1-nonanal or pelargonaldehyde, and n-decylaldehyde, also known as decanal, are commercially available from Aldrich, Milwaukee, Wis. It will be appreciated, however, that the N-alkyl-DNJ used in this combination drug therapy is not limited to any particular method of synthesis of the N-butyl-DNJ, N-nonyl-DNJ, N-decyl-DNJ, or other N-alkyl derivatives of DNJ. [0028] The glucocerebrosidase used in the combination drug therapy also is a known drug as described above. For example, it can be derived from human placental tissue by conventional isolation and purification techniques or prepared by recombinant DNA procedures. Conventional methods of isolation and purification from human placental tissue are described By Dale and Beutler, Proc. Natl. Acad. Sci. USA 73, 4672-4674 (1976) and in U.S. Pat. No. 3,910,822. Suitable methods of production by recombinant DNA are described in U.S. Pat. Nos. 5,236,838, 5,549,892 and 5,879,680. The glucocerebrosidase can also be conjugated with carrier molecules such as, for example, polyethylene glycol (PEG) as described in U.S. Pat. Nos 5,705,153 and 5,620,884. It will be appreciated, however, that the glycocerebrosidase used in the combination drug therapy is not limited to any particular method of production. [0029] The N-butyl-DNJ, N-nonyl-DNJ, N-decyl-DNJ, and other N-alkyl derivatives of DNJ, can be used for treatment of patients afflicted with Gaucher's disease and other glycolipid storage diseases by conventional methods of administering therapeutic drugs. Thus, the active compound is preferably formulated with pharmaceutically acceptable diluents and carriers. The active drug can be used in the free amine form or the salt form. Pharmaceutically acceptable salt forms are illustrated, e.g., by the HCl salt. The amount of the active drug to be administered must be an effective amount, that is, an amount which is medically beneficial against Gaucher's disease or other glycolipid storage disease but does not present adverse toxic effects which overweigh the advantages that accompany its use. [0030] Other glycolipid storage diseases to which the method of the invention is directed are, e.g., Tay-Sachs disease, Sandhoff disease, Fabry disease, GM1 gangliosidosis and fucosidosis. DETAILED DESCRIPTION OF THE INVENTION [0031] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as forming the invention, it is believed that the invention will be better understood from the following preferred embodiments of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0032] [0032]FIG. 1 shows thin layer chromatography of (a) CHO and (b) HL-60 treated cells. Cells were cultured for four days in the presence of radiolabelled palmitic acid and the following concentrations of compound: a) control, no compound b)   50 μM NB-DNJ c)    5 μM NB-DNJ d)  2.5 μM NB-DNJ e)  0.25 μM NB-DNJ f) 0.025 μM NB-DNJ g)   50 μM NN-DNJ h)    5 μM NN-DNJ i)  2.5 μM NN-DNJ j)  0.25 μM NN-DNJ k) 0.025 μM NN-DNJ [0033] After extraction the radioactively labelled glycolipids were separated by TLC and visualized by radioautography. NB-DNJ is N-butyl-DNJ. NN-DNJ is N-nonyl-DNJ [0034] [0034]FIG. 2 shows double reciprocal plots of the inhibition of the ceramide glucosyltransferase by N-butyl-DNJ (NB-DNJ). HL-60 cell ceramide glucosyltransferase activity was measured using (a) ceramide concentrations of 5-20 μM and (b) UDP-glucose concentrations of 0.59-5.9 μM. NB-DNJ concentrations of 5-100 μM were used. The inhibition constants (K i ) were calculated by plotting the Lineweaver-Burk slope against inhibitor concentration as shown in the inserts. [0035] [0035]FIG. 3 shows inhibition of HL-60 cell ceramide glucosyltransferase activity by N-butyl-DNJ (open circles) and N-nonyl-DNJ (closed circles). Activity was expressed as a percentage of control without inhibitor and the IC 50 values calculated from the rate curves shown. N-butyl-DNJ=27.1 μM; N-nonyl-DNJ=2.8 μM. [0036] [0036]FIG. 4 shows structural relationship between NB-DNJ and ceramide glucosyltransferase substrate. [0037] (a) Ceramide structure from the crystal structure of glucosylceramide. The acceptor hydroxyl is on C1 1 . [0038] (b) The structure NB-DNJ (N-alkyl) based on NMR studies and molecular modelling. [0039] (c) One possible overlay of ceramide and NB-DNJ. [0040] [0040]FIG. 5 is a bar graph of estimated radioactivity. Radiolabelled N-butyl-DNJ and N-nonyl-DNJ were added to cultured CHO, MDBK and HepG2 cells for the times (hours) indicated. Cells were extensively washed and acid precipitated. After solution in NaOH, cell associated radioactivity was determined as a percentage of radiolabelled compound added. [0041] [0041]FIG. 6 is a bar graph which shows organ distribution of radiolabelled N-butyl-DNJ (NB-DNJ) and N-nonyl-DNJ (NN-DNJ). Mouse body fluids and organs were collected for different times (30, 60, 90 minutes) after gavage with radiolabelled compound. Radioactivity in each sample was determined and expressed as a percentage of radioactivity recovered. Solid bars, NN-DNJ, hatched bars, NB-DNJ. [0042] In order to illustrate the invention in greater detail, the following specific laboratory examples are carried out. Although specific examples are thus illustrated herein, it will be appreciated that the invention is not limited to these specific, illustrative examples or the details therein. EXAMPLE I [0043] A comparison was made between N-butyl-DNJ and N-nonyl-DNJ for glycolipid biosynthesis inhibition which showed that potency is cell and chain length dependent. Chinese Hamster Ovary (CHO) cells and human myeloid (HL-60) cells grown in the presence of varying concentrations of inhibitor in addition to a precursor (radiolabelled palmitic acid) of glycolipid biosynthesis were treated with solvents to extract the glycolipids by the procedure described by Platt et al., J. Biol. Chem. 269, 8362-8365 (1994). [0044] The radiolabelled lipids were separated by TLC (FIG. 1) and bands corresponding to glucosylceramide and lactosylceramide were quantitated by scanning densitometry to estimate the reduction in glycolipid biosynthesis. These data were plotted to obtain inhibitory constants (IC 50 ) for both cell lines and compounds (Table 1). [0045] These data show that cell lines have different sensitivities to both N-butyl- and N-nonyl-DNJ. HL-60 cells are more than 10 times more sensitive to N-butyl-DNJ and 100 times more sensitive to N-nonyl-DNJ than CHO cells. This cell specificity is unexpected. In addition, N-nonyl is between 10 and 365 times more effective than N-butyl-DNJ. [0046] Detailed work to probe the kinetics of inhibition of the ceramide glucosyltransferase, the enzyme inhibited by alkylated deoxynojirimycin compounds, has demonstrated that these compounds are competitive inhibitors for ceramide and non-competitive inhibitors for UDP-glucose (FIG. 2). N-nonyl-DNJ has a 10-fold increased potency over N-butyl-DNJ in inhibiting ceramide glucosyltransferase in in vitro assays (IC 50 values of 2.8 μM and 27.1 μM respectively, see FIG. 3). [0047] The mechanism of action of alkylated deoxynojirimycin compounds is proposed to be that of ceramide mimicry and a model demonstrating this mimicry at the molecular level is shown in FIG. 4. An energy minimized molecular model of NB-DNJ and ceramide predicts structural homology of three chiral centers and the N-alkyl chain of NB-DNJ, with the trans-alkenyl and N-acyl chain of ceramide. This increased in vitro potency does not explain the dramatic difference in inhibition of glycolipid biosynthesis in cellular systems. [0048] The activity is explained by the differential uptake into cells. In three cell lines, CHO, MDBK and HepG2, radiolabelled N-nonyl-DNJ and N-butyl-DNJ were incubated for up to 24 hours and the amount of cell-associated radioactivity determined. In all cases N-nonyl-DNJ was increased by 3.5-5.0 fold. It is clearly the combination of the inhibitory effect and increased uptake that is important in potentiating the inhibition by N-nonyl-DNJ. [0049] Further evidence that longer alkyl chains are taken up much better than the shorter alkyl chains has been obtained by in vivo studies with mouse. After oral gavage with radiolabelled N-nonyl-DNJ and N-butyl-DNJ for 30, 60, and 90 minutes, the body fluids were collected and organs removed for estimations of radioactivity (FIG. 5). The amount of radioactivity recovered in the liver and brain was 10 fold higher for N-nonyl-DNJ than N-butyl-DNJ after 90 min (see Table 2). [0050] Evidence was obtained that longer (than C9) chain DNJ compounds are more effective ceramide glucosyltransferase inhibitors. This follows from proposed mechanism of action studies that demonstrate enhanced potency correlates with ceramide mimicry (FIG. 4). More specifically, N-decyl-DNJ (C10) shows inhibition at 50 times lower concentrations than N-butyl-DNJ in the HL-60 cell-based assay described above. In view of the above data, the long-chain N-alkyl derivatives of DNJ are more effective for treatment of glycolipid storage diseases. TABLE 1 Cells N-butyl-DNJ (IC 50 , μM) N-nonyl-DNJ (IC 50 , μM) CHO 25-50   2-2.7 HL-60 1.8-7.3 0.02-0.4 [0051] Table 1. Inhibition of glycolipids by N-butyl- and N-nonyl-DNJ. Radiolabelled glucosylceramide and lactosylceramide bands from FIG. 1 were quantitated by scanning densitometry and the percentage of control (no treatment, track a, FIG. 1) expressed in comparison to compound dose. From the linear curve, an IC 50 value was obtained. A range of values is quoted to represent variability of the radiolabelled products. TABLE 2 % recovered N-nonyl-DNJ % recovered N-butyl-DNJ Time (min) Liver Brain Liver Brain 30 27.1 0.4 8.5 0.2 60 12.6 0.3 2.8 0.1 90 13.5 0.4 0.9 0.03 [0052] Table 2. Recovery of radiolabelled compounds after administration in the normal mouse. Mouse body fluids and organs were collected at different times after gavage with radiolabelled compound. Radioactivity in each sample was determined and expressed as a percentage of radioactivity recovered (data from FIG. 5). EXAMPLE II [0053] When the N-butyl-DNJ, N-nonyl-DNJ, N-decyl-DNJ or other N-alkyl-DNJ as defined herein is used in combination with the glycocerebrosidase enzyme for the treatment of Gaucher's disease or other such glycolipid storage disease, the medical benefits of both types of drugs accrue to the patient with reduced amounts of either or both drugs than otherwise necessary by monotherapy to obtain equivalent or enhanced therapeutic results. These therapeutic benefits are obtained with a dosage of about 0.1 to 1000 mg of the N-alkyl-DNJ and a dosage of about 7.5 to 60 U per Kg of body weight of the glucocerebrosidase enzyme. [0054] One concern with combination therapy is that β-gluco-cerebrosidase is also inhibited by NB-DNJ. The IC 50 value is 520 μM in an in vitro assay, 25 fold higher than that required to inhibit the ceramide glucosyltransferase activity (IC 50 , 20.4 μM) (Platt et al., J. Biol. Chem. 269, 27108-27114, 1994). Therefore, the kinetic equilibrium for the metabolism of glucocerebroside in the presence of 5-50 μM NB-DNJ will favor reduced substrate and not cause storage by inhibition of glucocerebrosidase (Platt, et al., id 1994). In practice, it is extremely difficult to sustain steady state serum concentrations in excess of 50 μM NB-DNJ in orally dosed animals (Platt, et al., J. Biol. Chem. 272, 19365-19372, 1997). In the clinical trial of ND-DNJ a steady-state plasma concentration was achieved after 4-6 weeks of treatment. An oral dosing regime of 100 mg three times daily showed a peak plasma concentration of 6.8 μM (1.5 μg/ml) (Cox et al., Lancet 355, 1481-1485, 2000). [0055] However, in vivo the co-administration of NB-DNJ and glucocerebrosidase could lead to inhibition of enzyme activity and compromise potential combination therapy. It was therefore important to determine the kinetics of infused enzyme in mice treated with NB-DNJ. After five weeks of oral administration of NB-DNJ (4800 mg/Kg/day), sufficient to sustain a stable serum concentration of 50 μM (Platt et al., id, 1997), mice were tail vein injected with Ceredase® at 5-10 U/Kg. Glucocerebrosidase activity was measured after injection using 4-methylumbelliferyl-β-glucoside as substrate and peak serum activity and half life for enzyme was calculated (TABLE 3). TABLE 3 Peak Activity Half Life Group (n) (mU/ml) ± sem (min) ± sem Untreated control (8) 11.56 ± 3.11 2.079 ± 0.392 NB-DNJ Treated (7) 27.39 ± 7.24 3.361 ± 0.491 [0056] Table 3. Serum β-glucocerebrosidase activity in mice untreated or treated with 4800 mg/Kg/day NB-DNJ. Student's t-test was used to determine P-Values for activity and half life of enzyme in the two groups and were 0.076 and 0.064 respectively. [0057] These data reveal that the infused β-glucocerebrosidase activity was not inhibited in the presence of NB-DNJ. An apparent elevation was observed, but due to the variability in the analysis this did not show statistical significance. One possible explanation for an apparent increase in activity is that exposure to low concentrations of imino sugar stimulated hydrolysis by stabilizing the active site. Other lysosomal enzymes are known to be stabilized by imino sugar inhibitors (Fan et al., Nature Med. 5, 112-115, 1999). The circulatory half life of the enzyme was found to be similar to previously published values (Friedman et al., Blood 93, 2807-2816, 1999). [0058] However, in the presence of NB-DNJ the half life was extended, indicating that inhibitor protects enzyme from inactivation or reduces clearance by receptor mediated uptake (Friedman, et al., id, 1999). [0059] The foregoing data thus suggest that the pharmacological profile of β-glucocerebrosidase would not be compromised in the present of low concentrations of NB-DNJ, but can show improvement. [0060] Various other examples will be apparent to the person skilled in the art after reading the present disclosure without departing from the spirit and scope of the invention. It is intended that all such other examples be included within the scope of the appended claims.

A novel combination drug therapy is disclosed for the treatment of a patient affected with Gaucher's disease or other such glycolipid storage diseases. The method comprises administering to said patient a therapeutically effective amount of both a N-alkyl derivative of deoxynojirimycin (DNJ) and a glucocerebrosidase enzyme to alleviate or inhibit the glycolipid storage disease. The alkyl group has from about two to about 20 carbon atoms and preferably is butyl, nonyl or decyl.

TECHNICAL FIELD OF THE INVENTION [0001] The present invention generally relates to the texturing of materials used by the microelectronics and microsystems industry and more particularly the texturing of spinet iron oxides. STATE OF THE ART [0002] Obtaining the texturing of the materials used is often desired for many applications in microelectronics and more generally for the production of microsystems. [0003] Texturing, here, means the ordered characteristic of the crystallographic structure which such materials can gain. The most current example is silicon the physical and electric properties of which are significantly different, depending on the state thereof: single-crystal, wherein only one crystalorientation is present; polycrystalline, wherein the grains of a polycrystalline sample may have a marked crystal orientation but wherein the latter may also be randomly oriented relative to one another as this is the case for a powder; and eventually amorphous, wherein no crystal orientation can be detected, with the amorphous state corresponding to the case where the material is not crystallised at all. [0004] A range of materials likely to be adapted to numerous applications in microelectronics is that of iron oxides which can be found as various chemical products. A part thereof, currently called spinel iron oxides, revealed particularly adapted to the implementation of miscellaneous devices such as the non volatile memories (FeRAM), conductive-bridging resistive memories (CBRAM), infrared photodetectors, and to other applications taking advantage of their magnetic characteristic, for instance spintronics. [0005] This more particularly relates to magnetite the chemical composition of which is Fe3O4 and maghemite the chemical composition of which is Fe2O3 in its so-called gamma phase (γ-Fe2O3). [0006] Texturing a spinel iron oxide layer makes it possible to confer properties which are liable to significantly improve the operation of the devices wherein such layers are used. [0007] For most of the spinel iron oxide (for example Fe 3 O 4 ), the growth direction to be favoured, in the ecase of magnetism, is the crystalline [111] direction (or <111> taking into account all of the directions). The coefficients specified in square brackets correspond to direction index. The notation used for the texture is (111) (or {111} taking into account all of the crystalline planes), where indices into brackets correspond to Miller indices, that is the conventional way to call the planes in a crystal. [0008] These notations, using direction indices and Miller indices, are widely used by the whole microelectronic industry and is well known by the person skilled in the art. [0009] Indeed, the [111] direction is called “axis of easy magnetization” in the literature, axis along which it is easier to align the magnetization for these compounds. [0010] The table hereunder gives the physical properties of magnetite and maghemite for a better understanding of the invention. [0000] Magnetite Maghemite Fe 3 O 4 γ-Fe 2 O 3 Mesh parameter in nm 0.8936 0.83474 (10 −9 metre): Density 5.18 4.87 Type and resistivity at Semi-conducting Insulating 300° K in Ohm · cm: 5 × 10 −3 1 × 10 19 Type of magnetism: Ferrimagnetic Ferrimagnetic [0011] Magnetite and maghemite can be formed using many known techniques and more particularly: oxydation of less oxidized phases (Fe or FeO); by MBE, the acronym for <<molecular beam epitaxy>> i.e. a technique consisting in sending one or more molecular jet(s) onto a substrate previously selected to make an epitaxial growth; by PLD, the acronym for <<pulsed laser deposition>> which is a method of thin film deposition using a high intensity laser beam also called a <<pulsed laser ablation>> and which makes it possible to sputter the atoms of a target which are going to condense on a substrate; by magnetron cathodic sputtering; by IBD, the acronym for <<ion beam deposition>>: by ultrasonic spray pyrolysis according to the so-called <<sol-gel>> technique [0018] To obtain a textured magnetite or maghemite layer, the known solutions start from under-layers made of materials such as: sapphire (Al 2 O 3 ); silicon (Si); gallium arsenide (GaAs); copper (Cu); ruthenium (Ru); strontium titanate SrTiO 3 ; zinc oxide (ZnO); platinum (Pt) and more particularly magnesium oxide (MgO). [0019] For example, the publication entitled <<Atomic and electronic structure of the Fe 3 O 4 (111)/MgO(111) model polar oxide interface>> by V. K. Lazarov, M. Weinert, S. A. Chambers, M. Gajdardziska-Josifovska, published in 2005 in the <<Physical Review B 72>> published by <<The American Physical Society>>, recommends to obtain a magnetite layer (Fe 3 O 4 ) the crystalline structure of which is (111)-oriented by epitaxial growing from a magnesium oxide (MgO) layer. [0020] It should be noted that, to obtain the texturing of magnetite, the magnesium oxide under-layer must be mono-crystalline, and have an (111) orientation. This necessarily implies constraints as regards the method. [0021] More particularly, this solution requires to obtain a single-crystal magnesium oxide <<bulk substrate>>, which is expensive, and in practice induces a limitation of the size of the substrate. In addition, it is impossible to obtain complex or <<MEMS>>, the acronym for <<microelectromechanical systems>> stackings which refers to microelectromechanical systems, and no conventional microelectronics equipment can define patterns on this type of substrate. [0022] An alternative solution consists in using a thin textured (111) layer in contact with the spinel iron oxide layer. However, this requires to orientate such thin layer beforehand, using underlying crystalline substrates, which have also been carefully oriented. This alternative solution is thus very expensive too and always raises problems as regards the making of complex stackings and MEMS, even though the definition of patterns by conventional equipment is then possible anyway. [0023] It should also be noted that, in order to obtain the texturing of the magnesium oxide layer (MgO) with a crystal (111) orientation, high temperatures must be implemented in a range from 500° C. to 800° C. Such temperatures are not compatible with the presence of a circuit underlying the spinet iron oxide layer. [0024] The underlying circuit is typically an integrated circuit (IC), for example of the CMOS type, the acronym for <<complementary metal-oxide-semiconductor>>, which refers to the most commonly produced type of electronic circuits at present, by the microelectronics industry. [0025] As texturing must be executed in a layer located above a circuit and requires temperatures from 500° C. to 800° C., the manufacturing of the device thus becomes complex and thus very expensive. As a matter of fact methods for transferring previously structured layers should then be implemented to obtain this result. All the more so since the integrated circuit itself is already interconnected, i.e. has gone through the so-called <<BEOL>>, the acronym for <<back-end of line>> manufacturing steps and high temperature which might damage it can no longer be implemented. [0026] Therefor a need exists which consists in limiting or even in eliminating at least some of the drawbacks of the known solutions to obtain a spinel iron oxide layer textured in the growth [111] direction. SUMMARY OF THE INVENTION [0027] To reach this objective, one aspect of the present invention relates to a method for manufacturing a spinet iron oxide layer (also called a spinel structure iron oxide), textured along a preferred crystal orientation in the [111] direction, with the spinel iron oxide layer being a ferrite layer or a doped ferrite layer. The method comprises the production of a bottom layer of titanium (Ti) or titanium oxide (TiO x ) the thickness of which is preferably greater than or equal to eight nanometres; and then the production of a spinel iron oxide layer on said bottom layer. [0028] When developing the present invention, it was found that the spinel iron oxide layer has an excellent texturing when it is deposited onto a bottom layer of titanium (Ti) or titanium oxides (TiO x ). [0029] Surprisingly, such texturing of the spinel iron oxide layer along the [111] direction is obtained whereas the bottom layer has no preferred crystal orientation along the [111] direction. Obtaining a face-centered cubic structure for the spinel iron oxide layer from a bottom layer having a very different crystallographic structure (hexagonal structure for titanium and tetragonal for TiO 2 ) is, of course unforeseeable. Besides, the mesh parameters of ferrite and of the bottom layer are little compatible, a priori, which makes the result of the invention even more surprising. It seems that such an excellent texturing is a natural tendency, with the grains of magnetite or maghemite arranging relative to the bottom layer of titanium (Ti) or titanium oxide (TiO x ). [0030] Then it is not necessary to provide a textured bulk substrate, such as an MgO substrate. Preparing a thin textured layer is not necessary either. The invention thus makes it possible to reduce or even eliminate the drawbacks of the known solutions to obtain a textured ferrite layer. More particularly, the nature of the Ti or TiO x layer is independent of the N-2 layer (the layer prior to the deposition of TiO 2 ), which makes it possible to insert such textured iron oxides at any stage of a conventional microelectronics process or during the production of complex structures of the MEMS type. Demonstrations have been made on an amorphous and crystalline underlayer. [0031] The cost of production for such a layer is thus significantly reduced. [0032] Besides, texturing the ferrite layer obtained with the invention does not depend much on the preferred orientation of the bottom layer, which still makes it possible to reduce the constraints of the method. [0033] Much advantageously, the method according to the invention is not very sensitive to the conditions of the deposition of the spinel iron oxide layer and the bottom layer. The invention thus makes it possible to widen the scope of the method. [0034] Advantageously too, the invention does not depend much on the materials underlying the bottom layer. It can thus be implemented in many devices. [0035] Another very advantageous aspect lies in that the texturing power conferred by the bottom layer is obtained even though there is no direct contact between the latter and the spinel iron oxide layer. Even better, such texturing power is little dependent on the nature of the intermediate layer in contact with ferrite, so long as this intermediate layer is not amorphous. This makes it possible to use various intermediate materials, for instance conductive materials or on the contrary insulating materials, in order to meet the constraints of the concerned application. [0036] Advantageously too, the method of the invention does not require the application of high temperatures to obtain the textured ferrite layer. This method is thus totally compatible with the current techniques in the CMOS microelectronics industry. [0037] Optionally, the method according to the invention may also have at least any one of the following characteristics: Advantageously, the thickness of the bottom layer is greater than or equal to 10 nanometres, preferably greater than or equal to 15 nanometres and more preferably greater than or equal to 20 nanometres. The thickness is measured along a direction perpendicular to the main faces of the substrate whereon the various layers are positioned. If the bottom layer has disk-shaped faces, the thickness thereof is then measured perpendicularly to such faces. According to one embodiment, the spinel iron oxide layer is a layer of magnetite (Fe 3 O 4 ) or a layer of maghemite (Fe 2 O 3 ) or a layer formed of a mixture of magnetite (Fe 3 O 4 ) and maghemite (Fe 2 O 3 ). According to another embodiment, the layer of spinel iron oxide is a layer of doped magnetite or maghemite. Advantageously, the spinel iron oxide layer is a layer of magnetite or of maghemite doped with: transition metals such as, for example: manganese (Mn), zinc (Zn), titanium (Ti), cobalt (Co), copper (Cu), cadmium (Cd), metals belonging to the alkaline earths such as for example magnesium (Mg), alkaline metals such as, for example: lithium (Li), sodium (Na) and lithium (Na with Li). Or still doped with at least one among the following elements: chromium (Cr), nickel (Ni), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), and/or (Au). According to an advantageous embodiment, the bottom layer is produced by physical vapour deposition (PVD). According to an advantageous embodiment, the production of the spinel iron oxide layer comprises chemical vapour deposition (CVD). Preferably, the production of the spinel iron oxide layer comprises chemical vapour deposition from metalorganic precursors (MOCVD). Preferably, the production of the spinel iron oxide layer comprises chemical vapour deposition at a deposition temperature of less than 450° C. According to an advantageous embodiment, the bottom layer is in contact with the spinet iron oxide layer. Then there is no intermediate layer between the spinel iron oxide layer and the bottom layer. According to another advantageous embodiment, the method comprises, prior to the producing of the spinel iron oxide layer, a step of producing at least one intermediate layer on the bottom layer so that the intermediate layer is positioned between the bottom layer and the spinel iron oxide layer after producing the spinel iron oxide layer. Advantageously, the intermediate layer is a layer of aluminium (Al), platinum (PI), or molybdenum (Mo). Advantageously, the intermediate layer has a thickness of less than 100 nanometres. The invention is also advantageous in that it can be applied to a very wide range of thicknesses for this layer. Preferably, the intermediate layer is in contact with the bottom layer and in contact with the spinel iron oxide layer. [0052] Another aspect of the present invention relates to a microelectronic device comprising a spinel iron oxide layer preferably textured along the spinel iron oxide layer growth [111] axis, with the spinel iron oxide layer being a ferrite layer or a doped ferrite layer. The device comprises a bottom layer of titanium (Ti) or titanium oxide (TiO x ) the thickness of which is preferably greater than or equal to eight nanometres and whereon the spinel iron oxide layer is positioned. [0053] Optionally, the device according to the invention may also have one of the following characteristics: According to an advantageous embodiment, the bottom layer is in contact with the spinel iron oxide layer. According to another embodiment, the device comprises at least one intermediate layer positioned between the bottom layer and the spinel iron oxide layer. Advantageously, the distance between the bottom layer and the spinel iron oxide layer is smaller than or equal to 100 nanometres. The invention is also advantageous in that it can be applied to a very wide range of distances. Advantageously, the device is so configured as to be used as a microbolometer or ferroelectric random access non volatile memories (FeRAM), or conductive-bridging resistive memories (CBRAM), or micromechanical or electromechanical systems (MEMS, NEMS) or optic, optoelectronic (MOEMS), or spintronic systems comprising at least one micro-electronic device according to the invention. [0058] Another aspect of the present invention relates to a microbolometer or a ferroelectric random access non volatile memory (FeRAM), or a conductive-bridging resistive memory (CBRAM), or a micromechanical or electromechanical system (MEMS, NEMS) or an optic, optoelectronic (MOEMS), or spintronic system comprising at least one micro-electronic device according to the invention. [0059] The other objects, characteristics and advantages of the present invention will appear upon reading the following description and referring to the appended drawings. It should be understood that other advantages can be incorporated herein. BRIEF DESCRIPTION OF THE FIGURES [0060] The aims, objects, characteristics and advantages of the invention will be more easily understood upon reading the detailed description of an embodiment of the latter which is illustrated by the following appended drawings, wherein: [0061] FIG. 1 shows, for reference, a diffractogram of a sample of not textured magnetite powder. [0062] FIG. 2 shows the diffractogram of a sample of magnetite obtained from a titanium underlayer. [0063] FIG. 3 shows the diffractogram of a sample of magnetite obtained from a titanium oxide underlayer. [0064] FIG. 4 shows the diffractogram of a sample of magnetite wherein an intermediate layer of molybdenum has been introduced between the bottom layer made of titanium and magnetite. [0065] FIG. 5 shows the diffractogram of a sample of magnetite wherein an intermediate layer of platinum has been introduced between the bottom layer made of titanium oxide and magnetite. [0066] FIG. 6 is a picture obtained with transmission electron microscopy equipment of a section of a magnetite layer on a bottom layer made of titanium oxide. [0067] The figures are given as examples and are not restrictive to the invention. They are principle schematic representations intended to facilitate the understanding of the invention and are thus not necessarily at the same scale as the practical applications. More particularly, the relative thicknesses of the various layers are not representative of reality. DETAILED DESCRIPTION OF THE INVENTION [0068] It should be noted that in the present invention, the words <<on>>, <<is deposited over>> or <<underlying>> or the equivalent thereof do not mean <<in contact with>>. Thus, for instance, depositing a first layer onto a second layer does not necessarily mean that the two layers are directly in contact with each other, but this means that the first layer at least partially covers the second layer by being either directly in contact therewith or by being separated therefrom by at least another layer or at least another element. [0069] The method of the invention applies to obtaining a layer of magnetite Fe 3 O 4 or maghemite having a chemical composition Fe 2 O 3 in its so-called gamma phase (γ-Fe 2 O 3 ). The invention also relates to the layers made of a mixture of magnetite and maghemite. As will be mentioned more precisely in the description hereunder, it also covers the case where the ferrite layer is doped. [0070] In the present patent application, a spinel iron oxide layer can also be called a spinel structure iron oxide layer. Spinel iron oxides have a face-centered cubic structure (CFC). The layer can be doped so long as the spinel structure (Face-centered cubic CFC) has not been modified. [0071] For clarity and conciseness, within the scope of the present invention, “spinel iron oxide layer” will refer to: a layer of magnetite, a layer of maghemite, a layer of a mixture of magnetite and maghemite, a layer of doped maghemite and/or of doped magnetite. [0072] In the description hereunder, the invention will be disclosed in greater details for the embodiments wherein the spinel iron oxide layer is a layer of one among magnetite or maghemite. However, all the characteristics and steps of the embodiments will be applicable to the embodiments wherein the spinel iron oxide layer is a layer of the other one among magnetite or maghemite or a layer of a mixture of magnetite and maghemite or still a layer of maghemite or magnetite or a mixture of magnetite and maghemite which is doped. [0073] The method of the invention, which is disclosed hereafter, enables to provide ferrite in thin layers with a significantly marked crystallographic texturing. As discussed in the section on the state of the art, texturing here means the oriented feature of the crystallographic structure that such materials can acquire, opposite to the extreme case of a polycrystalline material having all the crystal orientations in an equivalent way, which is the ideal case for a powder. For instance, a powder may be composed of crystallized grains, but the grains of which are randomly oriented relative to each other. The two extreme cases of texturing are the single-crystal and the powder. [0074] The method of the invention makes it possible to obtain a good texturing of the spinel iron oxide layer starting from a bottom layer made of titanium (Ti) or titanium oxide (TiO x or TiO 2 ). [0075] The spinel iron oxide layer is deposited onto the bottom layer of titanium or titanium oxide (TiO x or TiO 2 ). This bottom layer, or underlayer is the key element of the correct texturing of these materials. [0076] Such bottom layer enables a large implementation of the method and makes it possible to reproducibly maintain a good texturing, whatever the deposition technique used: for instance MOCVD or sputtering, as mentioned hereunder. Texturing is relatively little dependent on the conditions of deposition. The texturing power of the bottom layer is also independent of the previously deposited underlayers. These may be amorphous or crystalline. The texturing power of the bottom layer is also independent of the intermediate layers in direct contact with the ferrites insofar as the intermediate layer is not amorphous). [0077] Magnetite and maghemite texturing reveals little dependency on the state of oxidation of the bottom layer, which is an advantage and gives additional flexibility to the implementation of the method. The insulating or conducting characteristics of titanium and the oxides thereof gives flexibility to the adaptation of the considered applications. [0078] To obtain a good vapour phase deposition MOCVD, a bottom layer of Ti, TiO x or TiO 2 with a thickness of at least 8 nm is preferred. A thickness of at least 15 nm is preferably selected, which makes it possible to improve the quality and the reproducibility of texturing. From 20 nm, the texturing quality almost no longer increases with the increase in the thickness of the bottom layer. [0079] According to a preferred but not restrictive embodiment, the production of a spinel iron oxide layer uses a method currently used by the microelectronics industry which is the vapour phase chemical deposition from gaseous precursors, which are, in this preferred case, metalorganic precursors (MO). This technique is referred to by its acronym MOCVD. This method can easily be implemented and is not expensive. [0080] The speed of the MOCVD deposition of magnetite and maghemite may be high. It typically ranges from 10 to 100 nm/minute. The morphology of the thin film and the stoichiometry thereof may be adjusted during the deposition. [0081] The method of the invention is perfectly adapted to industrial use and enables a good compromise, which reconciles the crystal quality of the deposited material, the cost of production and the rate of production thereof. [0082] For this purpose, the method preferably uses iron pentacarbonyl (Fe(CO) 5 ) as a precursor. This precursor requires a reactive gas of oxygen (O 2 ) to be used for forming the iron oxides. The deposition temperatures then range from the decomposition limit of the precursor which is above 150° C. and an upper limit which will mainly depend on the capacity of the underlying circuit to support high temperatures without damage. Typically, for a CMOS circuit, the limit is 450° C. Besides, it should be noted that, with a high temperature, the formation of haematite occurs, depending on the selected precursor, which must be avoided. It has been observed that this temperature is above 500° C. with iron pentacarbonyl (Fe(CO) 5 ) mentioned above and varies as a function of the selected oxygen rates. The lower limit for temperature is fixed by the precursor itself. It is typically 200° C. for Fe(CO) 5 even though, from 150° C. a partial decomposition can be observed. It should be noted that the above-mentioned temperatures can be very different if another precursor is used. For example the decomposition temperature of Fe(C 5 H 5 ) 2 is 400° C. and that of FeO 6 C 18 H 27 is 140° C. Such temperatures are not restrictive, however. An increase in temperature is a favourable factor for the texturing of the spinel iron oxide layer. However, the temperature beyond which haematite would be formed should not be exceeded. The deposition temperature is thus mainly chosen according to the constraints imposed by the layers underneath the spinel iron oxide layer, for instance. To summarize, temperature is chosen so that magnetite is preserved and it causes no damage to the underlying circuit. [0083] The pressure inside the enclosure amounts to a few milliTorr to a few Torr. [0084] A preferred texturing marked in the [111] direction of the ferrites has been observed for a wide range of deposition temperature ranging from 300° C. to 450° C. This preferred crystal orientation in the [111] direction is also noted for a large range of pressures, typically between 30 milliTorr and a few Torr. [0085] The bottom layer made of Ti is formed by physical vapour phase deposition or PVD. The deposition conditions may be within a range of temperature from the ambient temperature to 450° C. It should be noted that the microelectronics industry knows how to implement PVD type Ti deposition in a range of temperature from −20° C. to 480° C. [0086] The deposition power may vary between 200 Watts and 12 kiloWatts. Using low power and temperatures for the deposition favours the forming of small grain thin layers, which is advantageous for Ti oxidation. [0087] The objective is identical, whether for the deposition of pure Ti or Ti intended for forming TiO x or TiO 2 . To form Ti oxides, a second step is necessary: the oxidizing annealing. The deposited Ti layer is then submitted to an oxidizing annealing, typically between 350° C. and 750° C. (less than 450° C. for a CMOS application) depending on the desired type of TiO x . It should be noted that, between 300° C. and 750° C., rutile TiO 2 is obtained. At lower temperatures, a material less oxidized or oxidized only in surface, rather than the TiO x type can be obtained. At a higher temperature, the risk is that phase may change: anatase, without it being a limit to the selection of temperature however. The annealing temperature also conditions the main crystal orientation which is (100) for low temperatures and (101) for high temperatures. TiO x or TiO 2 formed directly during the deposition (for example by sputtering Ti with O 2 as a reactive gas or MOCVD of Ti with O 2 as a reactive gas) would give the same results. [0088] It should be reminded that the preferred crystal orientation of the spinel iron oxide layer is surprisingly less dependent, or even not at all dependent on the preferred crystal orientation of the bottom layer. Indeed, a spinel iron oxide layer having a preferred crystal orientation in the [111] direction is obtained whereas the bottom layer may have a (100) or (101) texture for instance. In addition, crystalline systems may be different; Fe 3 O 4 has a face-centered cubic structure whereas rutile TiO 2 has a quadratic (tetragonale) structure. [0089] The characterisation technique chosen to study the texturing of the material is X-ray diffraction (DRX). [0090] FIG. 1 shows, for reference, a diffractogram 200 of a sample of not textured magnetite powder. Such diagram conventionally shows, in this type of analysis, the intensity of the reflection peaks obtained, on the axis of ordinates, versus, on the axis of abscissae, the diffraction angle (2θ) of the X ray beam. It should be noted that 2θ is the retrieved angle (angle between the incident beam and the diffracted beam), θ is the incident angle which the sample is exposed to, i.e. the angle formed by the beam with the surface of the sample. As shown in FIG. 1 , the person skilled in the art can determine, according to the angular position of the peaks, the Miller indices 210 of the crystalline planes corresponding to the analysed crystalline structure. A large distribution of the crystal orientations is of course found for the not textured magnetite powder of this sample. It can be noted that the reference diffractogramm of maghemite is very close to that of magnetite. A slight shifting of the peaks in 2Theta (resulting from the slight difference in the mesh parameter), or even some superlattice peaks can be observed, only. Generally speaking, magnetite can hardly be differentiated from maghemite in X ray diffraction. [0091] It should be noted as from now that, with this type of indication, Miller indices multiple of each other correspond to identical crystalorientations. For example, the indices (444), (333) and (222) have the same crystal orientation as the (111) index, i.e. the growth [111] direction. [0092] More precisely, the relationship between the lines or reflection peaks (111), (222), (333) and (444) is obtained using Bragg law as follows: [0000] nλ= 2( d ( hkl ) sin θ), [0000] where n is an integer, called the reflection order λI is the wavelength of the incident X-wave d(hkl) is the interreticular spacing for given hkl index levels θ is Bragg angle [0093] As regards the line or reflection peak 111 diffraction order 2 (n=2) then: [0000] 2λ=2 d (111) sin θ [0000] λ=2( d (111)/2) sin θ [0000] λ=2 d (222) sin θ [0094] This implies the existence of all these lines, since there is no condition for the extinction thereof according to the hkl indices planes having the same parity. In the case of a crystalline structure of the <<face-centered cubic>> type the indices planes (111) or (200) diffract but, for instance, the orientation (210) does not. [0095] The lines (111), (222), (333) and (444) come from the same crystallites and their presence reveals a geometric factor inherent in Bragg law only. [0096] Within the scope of the present invention, the growing [111] direction, also called the preferred crystal orientation in the [111] direction, implies the appearance of lines (111), (222), (333) and (444) etc. The (111) planes are stacked perpendicularly relative to the normal to the surface of the substrate (or growth direction). [0097] It is important to compare the diffractograms of the following Figures, experimentally obtained with the method of the invention, with the reference shown in FIG. 1 . As a matter of fact the reference diffractogram shows the distribution of the peak intensity in the case of a powder sample, i.e. all the crystal orientations of which are potentially present in substantially identical proportions. As regards the diffracting volume, there are as many grains oriented in the [111] direction as grains oriented in the [311] direction. This makes it possible to take the structure factor of each line into account. The intensity of the diffracted beam is thus disclosed by a mathematical expression relating the coordinates of the mesh atoms, their electronic diffusion factor h, k, l indices of the planes family in the diffraction position (Miller indices). What is important is to compare the evolution of the distribution of the intensity of peaks present in the diffractograms of the following figures ( FIGS. 2 to 5 ) with the reference diffractogram ( FIG. 1 ), and thus to determine whether a crystal orientation dominates the other ones in spite of some uncertainties inherent in the analysis of textured thin films which might remain. [0098] As disclosed in details in the following, the diffractograms of FIGS. 2 to 5 very distinctly show that the (111) orientation is dominating relative to the (311) orientation which is the most intense line for a powder. [0099] FIG. 2 shows the diffractogram 300 of a sample of magnetite obtained from a (101)-oriented bottom layer of titanium (Ti) having a thickness of 20 nm. It can be seen that the layer of magnetite deposited above, on a thickness of 230 nm acquires the same crystal orientation 310 which is the main orientation (111) since, as noted above, the lines with the indices (222), (333) and (444) are equivalent. Only one different line (311) having a low intensity 320 appears in this diagram. [0100] The fact that the line (111) cannot be found on the diffractogram of FIG. 2 , whereas the lines (222), (333) and (444) are visible is only the result of the selected scanning angular range and the angle of diffraction measured which is traditionally noted 2θ. The line (111) of the ferrites deposited according to the method of the invention is positioned at 18.29°, using the Kalpha line of copper, a material the anode of the diffraction device used is made of. This results in that, for an angular measure range in 2θ between 25° and 89° it shall not be visible even though the corresponding orientation does exist. [0101] FIG. 3 shows the diffractogram 400 of another sample of magnetite obtained from an (100)-oriented bottom layer of titanium oxide (TiO 2 ) having a thickness of 20 nm. It should be noted here too that the magnetite layer which has been deposited on the top, on a thickness of 230 nm does acquire the same crystal orientation 410 which mainly occurs in the (111) orientation. As mentioned above, only one different line (311) having a low intensity 420 appears in this diagram. The presence of a peak 430 having a very low intensity corresponding to the TiO 2 of the underlayer should also be noted. [0102] It should also be noted that the midway width, or FWHM, the acronym for <<full width at half maximum>>, of the (111) peak for the magnetite deposited on TiO 2 is equal to 2.15° (as determined using a so-called <<rocking curve>> analysis, during which a tilting motion is applied to the sample), which is a very low value for a polycrystalline film deposited under these conditions. This suggests that the crystallites, in addition to texturing in the (111) orientation, are not much affected as regards their orientation relative to the plane of the sample surface. [0103] It has also been advantageously noted that an intermediate layer, deposited on Ti, TiO 2 or more generally TiO x adopts the reticular parameters of this bottom layer and makes it possible to keep an excellent texturing of the spinel iron oxide layer. [0104] The intermediate layer is preferably in contact, by one of its faces, with the bottom layer, and by the other face with the spinel iron oxide layer. The intermediate layer has no upper and no lower limit as regards thickness. The intermediate layer is preferably produced by PVD. [0105] According to an alternate solution, several intermediate layers are positioned between the bottom layer and the spinel iron oxide layer, insofar as these concern crystalline materials the crystalline parameters of which are close. [0106] Preferably, the intermediate layer is formed of at least one of the following materials: molybdenum (Mo), platinum (Pt), Aluminium (Al). All the not crystallized, and thus amorphous materials, may be excluded. [0107] The diffractograms of FIGS. 4 and 5 show the results of the texturing of the spinel iron oxide layer obtained with an intermediate layer between the bottom layer and the spinel iron oxide layer. [0108] FIG. 4 shows the diffractogram 500 of a sample of magnetite wherein an intermediate layer has been introduced between the bottom layer made of titanium (Ti) and the magnetite. In this case, the intermediate layer is molybdenum (Mo). Molybdenum is textured with an (110) orientation by the underlying titanium layer having an orientation 001. The magnetite underlayer has a thickness of 230 nm on a molybdenum and titanium underlayer having a thickness of respectively 50 nm and 20 nm. The preferred orientation of molybdenum has a peak 510 strongly marked with an (110) orientation. [0109] FIG. 5 shows the diffractogram 600 of a sample of magnetite wherein an intermediate layer of platinum (Pt) has been introduced, in this case between the bottom layer of Titanium oxide (TiO 2 ) and magnetite. Platinum is textured with an (111) orientation by the underlying titanium layer having an (101) orientation. The magnetite underlayer has a thickness of 230 nm on a platinum and titanium oxide underlayer having a thickness of respectively 50 nm and 20 nm. [0110] It can be noted that the crystalline texturing of magnetite is strongly marked in the [111] direction. This excellent texturing is confirmed by a very low FWHM of 2.15° seen on the <<rocking curve>> of the (111) peak of magnetite vs TiO 2. It should be reminded here that (111) and (222) come from the same grains. The angular value of 2.15° is a very good value which means that an important volume of crystallites (grains) have their (111) planes sloping by 2.15° or less relative to the surface of the sample which is perpendicular to the growing direction. [0111] A highly textured magnetite layer is also obtained, which has a preferred crystal orientation in the [111] direction using a bottom layer of titanium Ti and an intermediate layer of aluminium (Al). [0112] Aluminium and platinum have <<face-centered cubic>> structures the mesh parameter of which is equal to half that of Fe 3 O 4 , within a few percents. The following table illustrates the results of the texturing obtained with and without the bottom layer. The result is that the addition of the bottom layer significantly improves the texturing of magnetite. [0000] Stacking FWHM of the Preferred Other orientations used Rocking Curve orientation noted Fe 3 O 4 /Al 2.6° (111) (111) only (111)/Ti/SiO 2 (amorphous)/Si Fe 3 O 4 /Al High (above 8°) (111) (311) of the Fe 3 O 4 , (111)/SiO 2 the crystalquality of Al (amorphous)/Si is also reduced Fe 3 O 4 /Pt 2.5° (111) (111) only (111)/TiO 2 /SiO 2 (amorphous)/Si Fe 3 O 4 /Pt 5.2° (111) (311) of the Fe 3 O 4 , (111)/SiO 2 the crystalquality of Pt (amorphous)/Si is also reduced [0113] It should also be noted that the texturing bottom layer must, in any case, have a minimum thickness to be efficient. Typically, a thickness above 8 nm and preferably above 10 nm ensures a good texturing of ferrite. [0114] It should be noted that the magnetite obtained has a polycrystalline nature as shown in FIG. 6 which has been made using <<transmission electron microscopy>> or TEM equipment. This method reveals a large majority of large grains, having the same crystalorientation. As a matter of fact, this figure shows the planes parallel to the TiO 2 surface of magnetite which are well crystallised: no breaking has occurred at the stacking and this stack is kept clean and parallel. [0115] The invention also extends to doped ferrites. As a non restrictive example, an excellent texturing in the [111] direction is obtained with layers of Co x Fe 3-x O4 and Ni x Fe 3-x O4. [0116] Several dopants can be considered, among which: manganese (Mn), zinc (Zn), chromium (Cr), nickel (Ni), titanium (Ti), cobalt (Co), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au). [0117] Dopants may be present in very small, or even infinitesimal quantities, up to very high values, above atomic 30%. If D is the doping element, doping is most often noted DxFe3-xO4 with, in general, x ranging from 0 to 1, for instance x=0.5. The value of x may sometimes be above 1. From a few percents, this doping can be detected by EDX, the acronym for <<energy dispersive X-ray spectrometry>> using a MEB or TEM microscope. For smaller quantities, a large number of techniques are available to access stoichiometry: by secondary ion mass spectrometry or SIMS; or by Rutherford backscattering spectrometry or RBS. An evolution of stoichiometry can also be noted according to the variation in the mesh parameter by integrating elements having a different atomic radius which will modify the dimensions of the crystalline mesh. [0118] Besides, if the experiment results have been established using samples obtained by MOCVD type chemical vapour deposition, all the deposition methods used by the microelectronics industry are likely to be used for obtaining the ferrite layer. More particularly, so-called IBD and PLD techniques, mentioned above, are liable to be suitable, as well as magnetron cathodic sputtering and physical vapour phase deposition or PVD. [0119] As another alternative to a deposition by MOCVD, a sputtering deposition technique can be used, by sputtering a target with iron or a target with dopant, for instance a target made of nitride or cobalt, by Argon plasma and dioxygen. The following conditions may be foreseen: Temperature of the substrate: between the ambient temperature and 700° C. for instance Sputtering power around 30 W Pressure of less than 10 −3 mbar From 2 to 5% of oxygen with respect to Argon. [0124] It should also be noted that the deposits of the MOCVD type used for forming the ferrite layer revealed that the method parameters, such as temperature, pressure etc. only slightly affect the texturing of ferrite. On the contrary it is the bottom layer made of Ti or the oxides thereof which is the key element for texturing the ferrites layer. [0125] It should also be noted that the films of textured magnetite and maghemite potentially interest many other fields such as spintronics, magnetism, so-called FeRAM non volatile memories, electromechanical microsystems or MEMS. [0126] Eventually, it should be noted that the bottom layers of titanium and titanium oxides are responsible for the excellent crystallographic texturing of the magnetite obtained and that the conditions of the magnetite deposition are secondary. It has been noted that the grains of magnetite naturally arrange with respect to the bottom layer made of Ti, TiOx or TiO 2 . The texturing power of such bottom layers is independent of the layers deposited before the bottom layer and the intermediate layers in direct contact with the ferrites. This is a particularly advantageous characteristic of the method of the invention. Another advantage is that the preferred orientation of this underlayer has little, or even no effect on the (111) texturing of ferrite. [0127] The results obtained with magnetite can be extrapolated to maghemite which has a very similar crystalline structure. The change of phase between magnetite and maghemite is a topotactic reaction. A mixture of magnetite/maghemite can thus be obtained without the crystalline structure of the thin film and the preferred orientation of these grains being changed. It should be noted that it is possible to switch from magnetite to maghemite using an oxidizing annealing of magnetite. [0128] The invention is not limited to the embodiments described above and extends to all the embodiments covered by the following claims.

The invention relates to a method for producing a spinel iron oxide layer. textured according to a preferred crystal orientation along the [111] direction, with the spinel iron oxide layer being a ferrite layer or a doped ferrite layer, characterised in that it comprises: producing a bottom layer of titanium (Ti) or titanium oxide (TiOx), with the thickness of the bottom layer being greater than or equal to eight nanometres; producing a spinel iron oxide layer on the bottom layer produced beforehand. It also relates to a device comprising a layer of textured ferrite.

BACKGROUND OF THE INVENTION In the case of grinding machines for the flanks of teeth which operate by way of the screw rolling process and which have a rigid gear train between a grinding worm and a workpiece upon which gear teeth are to be formed or have a synchronous drive of the grinding worm and the workpiece, the bringing of the grinding worm into engagement with the workpiece takes place generally while the tool and the workpiece spindle is at a standstill, i.e. visually and by hand. In a known construction as seen in German Pat. No. 883,551 engagement of the grinding worm with the workpiece on machines for producing gear teeth by grinding, which is activated via two synchronous motors, takes place not by turning off the driving motors of the grinding worm and the workpiece in case of a change of the workpiece, but only by uncoupling the driver of the workpiece. The new workpiece must again be clamped onto the clamping mandrel in precisely the same position in relation to a tooth space, as the previous gear. This clamping process may, as is self evident, also be used in case of gear tooth grinding machines which have a rigid gear train between the grinding worm and the workpiece. In another prior art construction, as in German Pat. No. 1,286,883 locally fixed positioners, connected with the machine operate a phase shifter, which rotates one of two synchronous motors. The workpiece however, must be indexed at the same time, that is it must be clamped in a fixed position. In the case of another known gear tooth grinding machine U.S.S.R. Pat. No. 200,394, inductive transmitters are provided for the determination of the position of the tool and workpiece for the purpose of automatic adjustment of one or several speeds of the grinding worm in which these transmitters are connected to a phase meter. The phase meter is connected to an adjusting motor via an electric amplifier. The motor causes an axial shift of the grinding disc into synchronism with the speed of the grinding worm and the tooth gap of the workpiece. The workpiece, in order to simplify the construction of the workpiece transmitter, is inserted into its electromagnetic circuit in such a way that it serves as a rotor while the stator is made in the manner of exchangeable tooth sectors which must always correspond with the teeth of the gear that is to be processed. In order to be able to equip gear tooth grinding machines which operate in the screw rolling process with a grinding worm, for economic reasons, neither moving of the grinding worm by hand nor an alignment of the workpiece on a clamping mandrel for the purpose of maintaining the position of the teeth of the workpieces may be used. The solution to the problem according to the referenced U.S.S.R. patent is to use gears which may be energized electromagnetically. According to this proposal however, exchangeable tooth sectors are required which must always coincide with the toothing of the gear to be processed. SUMMARY OF THE INVENTION It is the object of the invention to create a device of the above-mentioned kind which makes possible automatic insertion of a tool rotating at a forced speed which may be used on gear processing machines with electronic control in which the required correctional movement is carried out by additional rotational movement of the workpiece. However, it should also be possible to use gear processing machines which have a rigid gear train between the tool and the workpiece or have synchronous drive of the tool and the workpiece. In such a case, the correctional shift is accomplished by the axial shifting of the tool. Furthermore, apparatus so constructed is also suitable for the processing of workpieces of any working material, thus, for example, also of electrically non-magnetizable materials. For the solution of this task, the invention is characterized in that during the movement of the tool and of the workpiece prior to engagement, their respective position is measured by means of determining the positions relative to a fixed predetermined reference line, whereby in case of measurements extending over a certain number of successive tooth or speed spacings, a mean value is determined. For the approach of the reference line up to engagement, a correction is made according to the measurement or to the mean value of the measurement by an axial shift of the tool or by an additional rotation of the workpiece in the corresponding directional sense. The respective position of the tool and workpiece is measured advantageously by a determination of the distance of the centerline of a tooth of the workpiece from the centerline of a gap of the tool. According to the invention, the apparatus is characterized by a measurement transmitter which may be positioned between the tool and workpiece during operation of the tool and workpiece prior to engagement. The transmitter is adapted for the measurement of pneumatic differential pressure and has one pair of nozzles for each of the tool and the workpiece, whereby each pair of nozzles comprises an adjustable reference nozzle and a measuring nozzle which may be aligned with the tool or the workpiece. The measuring nozzle produces an electric signal corresponding to the measured differential pressure. A detection circuit is connected to the measuring nozzles for detecting movement of the tool gaps and teeth of the workpiece past the measuring nozzles. A first logical circuit is connected to the detection circuit which is connected with switching means for producing measurement pulses, the frequency of which is higher than the frequency of successive tooth or speed spacings. A counter is provided connected to the output of the first logical circuit for the algebraic summation of measuring pulses controlled by the starting signals of the detection circuit depending on the logical circuit, as well as a second logical circuit for the formation of correction signals in forward and backward directions depending on the content of the counter. Embodiments of the apparatus of the invention are explained subsequently with reference to the drawings. This explanation is made with reference to a gear tooth grinding machine which operates using the screw rolling process, i.e. with a grinding worm. Of course the present process and apparatus may also be used for the hobbing of pre-toothed gears on a hobbing machine. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A shows schematically and by cross-sectional views a grinding worm; FIGS. 1B to 1E show schematically and by cross-sectional views four cases of teeth of workpieces in relation to the grinding worm of FIG. 1A at the beginning of the present process; FIG. 1F shows a grinding worm as in FIG. 1A; FIGS. 1G-1H show schematically and by cross-sectional views two more cases of teeth of workpieces in relation to the grinding worm of FIG. 1F; FIG. 2 shows schematically the determination of the mean value of the measurements via three tooth spacings or three teeth of a workpiece, i.e. the position of three workpiece teeth, relative to the position of the teeth of the grinding worm prior to and after a correctional shift; FIG. 3 shows schematically a gear tooth grinding machine with an electronic control circuit and an embodiment of the apparatus of the invention for the automatic control of the engagement of the grinding worm with the gear to be processed; FIG. 4 shows a block diagram of an electronic circuit arrangement of the control arrangement of FIG. 3; FIG. 5 is a flow diagram for the circuit arrangement of FIG. 4; and FIG. 6 is a showing of the orientation of FIGS. 6A and 6B; FIGS. 6A and 6B are detailed logic diagrams of the circuit arrangement of FIG. 4. DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to achieve engagement of the preprocessed teeth on the gear to be ground (which is moved manually or by means of an automatic charger on the grinding machine in to a clamped-down position) with the gap of the grinding worm, it is necessary in the presently described embodiment of the invention, that first the distance of the centerline of the workpiece tooth on the rotating gear closest to the gap of the grinding worm must be determined. As a starting point for the measurement of the mean distance of the workpiece tooth, one may, for example, advantageously select the starting point of the gap of the grinding worm on the head cylinder of the similarly rotating grinding worm. The measurement is accomplished in case of the present embodiment with two measuring nozzles used one at a time, one of which is directed toward the head cylinder of the grinding worm, the other toward the head cylinder of the workpiece. The teeth and the gaps between teeth moving past the measuring nozzles cause corresponding changes in pressure. In practice the pressure is not going to rise or drop absolutely abruptly at the beginning or the end of the teeth. The width of the teeth and of the gaps shown in FIGS. 1A to 1H are therefore shown schematically. In principle, they represent the signals delivered by the measuring nozzles, and not the actual width of the teeth and the gaps on the head cylinder. In FIGS. 1A to 1H cases of correspondence of teeth of workpieces to the gaps of the grinding worm, or cases of correspondence of the signals produced by the above-mentioned measuring nozzles of the grinding worm and of the workpiece gear are shown. In the FIGS. 1A and 1F, referring to the grinding worm, P designates the tooth spacing which comprises one tooth gap L S and one tooth Z S . The distance between centerlines of the gap L S of the grinding worm is designated by M LS . In all FIGS. 1A to 1H the limits of the tooth spacings P of the grinding worm are drawn with perpendicular dash-dot lines and the centerlines of the tooth gaps L S with perpendicular broken lines. In FIGS. 1B to 1E as well as 1G and 1H, six workpiece gears corresponding to the grinding worms of FIGS. 1A and 1F are shown which always comprise a first tooth gap L 0 , a first tooth Z 0 , a successive tooth gap L 1 and a successive tooth Z, as well as additional tooth gaps and teeth which are not herein shown. Furthermore, successive sections of the workpiece, lying within a tooth spacing P of the grinding worm have been indicated in the FIGS. 1B to 1E, 1G and 1H, namely: A the portion of the width of the tooth gap L 0 within the tooth spacing P, B the portion of the width of the tooth Z 0 within the tooth spacing P, C the portion of the width of the tooth gap L 1 within the tooth spacing P, and D the portion of the width of the tooth Z 1 within the tooth spacing P. It is easy to see, that the distance M ZW of the middle of the tooth of the workpiece from the above-mentioned reference point 0 at the beginning of a tooth gap L S of the grinding worm may be determined in all cases on the basis of the formula M.sub.ZW =A+(B-D)/2. (1) In this case, the centers of teeth of the workpieces are also indicated in the FIGS. 1B to 1E, 1G and 1F by perpendicular, broken lines. In order to achieve engagement of the teeth of the workpiece with the gaps of the grinding worm, the workpiece and the grinding worm must be shifted reciprocally by the amount of shifting V, shown in FIGS. 1B to 1E, 1G, 1H, prior to insertion of the rotating grinding worm into the likewise rotating workpiece. The amount of shifting V corresponds to the distance of the center of the tooth of the workpiece from the middle of the gap of the grinding worm. Since the reference point 0, for the purpose of determining the measurement, had been placed on the edge of the gap of the grinding worm as already mentioned, the amount of shifting V may be determined simply by the relation: V=M.sub.LS -M.sub.ZW. (2) Advantageously, the measurement may be accomplished by counting measuring pulses, which are always produced in the area of the teeth and tooth gaps of the grinding worm and of the workpiece moving past the measuring nozzles. As a result of an algebraic summing up of such measuring pulses, one may obtain a balance for each tooth spacing P of the grinding worm, which corresponds to the amount V of shifting. It will be of advantage in this case, if the measuring pulses are produced in dependence on the rotational speed of the workpiece and particularly if they are deduced from the pulses of a shaft encoder. With f M the frequency of the measuring pulses and f W the frequency of the workpiece pulses recorded with the shaft encoder on the workpiece, then in the simplest case: f.sub.M =f.sub.W =(ω.sub.W ·N.sub.W)/2π (3) where ω W is the angular velocity of the workpiece and N W the number of pulses per revolution of the workpiece, as taken from the shaft encoder on the workpiece. The frequency f M of the measuring pulses however, may also be the frequency f W of the workpiece pulses, multiplied by a certain factor, or in case of measurement over several tooth spacings P of the grinding worm, described subsequently, the frequency f W of the workpiece pulses divided by the number of tooth gaps. In order that the algebraic summing of the measuring pulses produced by tooth spacings P may produce a balance for all possible cases of the alignment of the teeth of the workpieces with the gaps of the grinding worm, corresponding to the shifting of the workpiece required for the approach and alignment of the centerlines in relation to the grinding worm, the balance must be formed according to a certain pattern dependent on each case of alignment. The relative positions of sections of the workpiece in relation to a tooth spacing P of the grinding worm are shown in FIGS. 1B to 1E, 1G and 1H and are designated as follows: Section E: gap L 0 inside gap L S Section F: tooth Z 0 inside gap L S Section G: gap L 1 inside gap L S Section H: tooth Z 1 inside gap L S Section I: gap L 0 inside tooth Z S Section J: tooth Z 0 inside tooth Z S Section K: gap L 1 inside tooth Z S Section L: tooth Z 1 inside tooth Z S Depending on whether a gap or a tooth of the workpiece of the gap or tooth of the grinding worm leads or lags, the measuring pulses must be summed with a minus or plus sign for the formation of the balance. Also, it must be taken into consideration whether or not in case of this leading or lagging of the gap or the tooth of the workpiece which corresponds to the respective tooth spacing P of the grinding worm and to the leading or lagging gap or to the leading or lagging tooth of the workpiece. In these cases, the measuring pulses must be added up with double the frequency of the measuring pulses. Thus the following counting pattern of measuring pulses results for the formation of the balance: Section E: L 0 inside L S : -f M /2 Section F: Z 0 inside L S : 0 Section G: L 1 inside L S : +f M /2 Section H: Z 1 inside L S : +f M Section I: L 0 inside Z S : -f M Section J: Z 0 inside Z S : -f M /2 Section K: L 1 inside Z S : 0 Section L: Z 1 inside Z S : +f M /2 Whenever a tooth Z 0 of the workpiece coincides wholly or partly with a gap L S of the grinding worm and their centerlines coincide, or correspondingly, the centerline of the succeeding gap L 1 of the workpiece coincides with the centerline of the succeeding tooth Z S of the grinding worm, the relative position of the grinding worm is correct for sections F and K of the workpiece so that no measuring pulses contributing to the corrective shift need be counted. Subsequently, numerical examples for calculating the center distance M ZW of a workpiece tooth from the starting point 0 of the pertinent gap of the grinding worm, the distance of the centerlines of the tooth of the workpiece to the gap of the grinding worm corresponding to the corrective shaft V of the workpiece in the case of measuring using a single tooth spacing P, as well as of the balance of the counting of the measuring pulses which correspond to the stated corrective shift V are listed. The examples are given for the cases of alignment shown in FIGS. 1A to 1H in which the values used are linear on the abscissa of the figures which may represent pulses, times or paths. Therefore, they may be shown as linear measurements i.e., they may be measured directly from the figures with due consideration of the scale. The following values were used as measures of reference for the scale: P=100 units M LS =35 units Case 1 of Correlation FIGS. 1A and 1B In this case the centerlines of the gap L S of the grinding worm and of the tooth Z 0 of the workpiece coincide. The centerlines spacing M ZW corresponds exactly to half the width of the gap of the grinding worm or to the distance M LS of the gap center measured from the same point of reference 0. In this case: A=21 units B=28 units C=51 units D=0. With the use of formula (1), the distance between centerlines M ZW is: M.sub.ZW =21+(28-0)/2=+35 and according to the relation (2) for the corrective shift V: V=35-35=0 The same result is obtained from the summing up of the measuring pulses in sections, E, F, G and K, whereby E=21 units F=28 units G=21 units K=30 units, namely V=-21 f M /2+0+21 f M /2+0=0 f M . Case 2 of Correlation, FIGS. 1A and 1C Here the tooth Z 0 of the workpiece is completely within the area of the gap L S of the grinding worm. However, the centerline of the tooth of the workpiece does not coincide with the centerline of the gap of the grinding worm. In this case: A=15 units B=28 units C=57 units D=0 E=15 units F=28 units G=27 units K=30 units Thus: M ZW =15+(28-0)/2=+29 V=35-29=+6 V=-15 f M /2+0+27 f M /2+0=+6 f M . Case 3 of Correlation, FIGS. 1A and 1D Here the tooth Z 0 of the workpiece is not completely inside the gap L S of the grinding worm. The distance between centerlines M ZW of the tooth of the workpiece is measured from the next point of reference 0 1 , shifted by a tooth spacing P (tooth Z 1 of the workpiece). In fact, the distance between centerlines M ZW with regard to the reference point 0 of the beginning of the gap L S of the grinding worm is negative as shown in FIG. 1D. Thus the measured distance between centerlines M ZW is given a minus sign. In case of this example: A=0 B=8 units C=72 units D=20 units F=8 units G=62 units K=10 units L=20 units Thus: M ZW =0+(8-20)/2=-6 V=35-(-6)=+41 V=0+62 f M /2+0+20 f M /2=+41 f M . Case 4 of Correlation, FIGS. 1A and 1E The tooth Z 0 of the workpiece here is precisely on the edge of the gap L S of the grinding worm with its centerline on the point of reference 0. In case of this example: A=0 B=14 units C=72 units D=14 units F=14 units G=56 units K=16 units L=14 units Thus: M ZW =0+(14-14)/2=0 V=35-0=+35 V=0+56 f M /2+0+14 f M /2=+35 f M . Case 5 of Correlation, FIGS. 1F and 1G Here the tooth of the workpiece is very broad or the workpiece delivers a very long output signal so that there exists alignment of the tooth Z 0 or Z 1 of the workpiece and of successive gaps L S of the grinding worm. As in Case 3 (FIGS. 1A and 1D), the distance between centerlines M ZW of the tooth of the workpiece is measured from the next reference point 0 1 shifted by one tooth spacing P (tooth Z 1 of the workpiece) and is negative. In case of this example: A=0 B=20 units C=34 units D=46 units F=20 units G=34 units H=16 units L=30 units Thus: M ZW =0+(20-46)/2=-13 V=35-(-13)=+48 V=0+34 f M /2+16 f M +30 f M /2=+48 f M . Case 6 of Correlation, FIGS. 1F and 1H The tooth Z 0 of the workpiece here is very narrow or the workpiece delivers a very short output signal so that there is an overlap of the gap L 0 of the workpiece with the tooth Z S of the grinding worm. In case of this example: A=78 units B=14 units C=8 units D=0 E=70 units I=8 units J=14 units K=8 units Thus: M ZW =78+(14-0)/2=+85 V=35-85=-50 V=-70 f M /2-8 f M -14 f M /2+0=-50 f M . The negative sign for the corrective shift V indicates that the shift takes place in reverse direction. As mentioned, the measurement of the distance between centerlines of the gap of the grinding worm and the tooth of the workpiece, and the determination of the required corrective shift are made advantageously in the form of a count of the measuring pulses. For the algebraic summing operation, a logical switching circuit described below may be provided. The precision of the measurement by means of measuring nozzles of a measurement transmitter unit depends above all on the precision of the form of the widths of the teeth or the bevellings of the teeth. In order to eliminate this influence as much as possible, the measurement may be made using a greater, freely selectable and adjustable number of tooth spacings P for which the mean value is formed using this greater number. The formation of the mean value may be carried out such that the deviations of the centerlines of the workpieces and the gaps of the grinding worms determined per tooth spacing, are summed algebraically with a pulse frequency f M which is as many times smaller than the pulse frequency f W of the workpiece as tooth spacings counted. As a result of this, it will become possible to keep the size of a dual counting system small and as a result the costs low. The mean value determined in this manner corresponds to a mean corrective shift V M to be carried out in the corresponding magnitude and direction by an axial shift of the grinding worm or by an additional rotary movement of the workpiece. The formation of the mean value for the corrective shift V M from the measurements by way for example of three tooth spacings P of the grinding worm is shown in FIG. 2. The measured deviations of the centerlines are designated by V 1 , V 2 and V 3 . The mean value V M is determined from: V.sub.M =(V.sub.1 +V.sub.2 +V.sub.3)/3 An axial shift of the grinding worm or an additional rotation of the workpiece by this mean value V M is carried out depending on the kind of construction of the grinding machine which is shown in FIG. 2 at the bottom of the figure. The deviations of the centerlines after the corrective shift by the mean value V M have been designated correspondingly by V 1 ', V 2 ' and V 3 '. In case of gear grinding machines which are provided with a rigid gear connection between the grinding worm and the workpiece, as well as in case of grinding machines which are actuated by a single synchronous motor, the corrective shift V M , because of the lack of means for the execution of an additional movement of rotation of the workpiece, is accomplished by an axial shift of the grinding worm. For this purpose, the grinding wheel head is equipped with an adjusting motor for execution of the axial shift of the grinding worm. In those cases, where an arrangement for the execution of axial shiftings or shifting of the grinding worm already exists, the same motor may be used under certain circumstances. The signals for the execution of the shifting, however, would have to be changed in form depending on the tooth spacing. In case of gear grinders which however are equipped with an electronically controlled positive movement arrangement, the corrective shifting may be accomplished by an additional rotational movement of the workpiece. Since electronic controls for positive movement for grinders for tooth flanks, as well as for hobbing millers, generally allow the workpiece to follow the tool, it will be effective in the present process to employ the pulses which are produced in response to the revolution of the workpiece are used for the determination of the corrective shifting. Since they correspond directly to a deviation of the angle or rotation, they may be fed directly into the electronic control system of the grinder. It is furthermore possible to carry out a count of the workpiece teeth and gaps of the grinding worm which have actually moved past the two calibrated nozzles of the sensor unit by means of a counter, the counting limit of which corresponds to the desired number of tooth spacings for which the formation of the mean value for the corrective shifting V M is carried out. In case that the number of the counted teeth of the workpiece does not coincide with the number of the counted gaps of the grinding worm, swing-out of the sensor unit from the measuring zone and also the engagement of the grinding worm with the workpiece to be processed are blocked. The grinding cycle may not be started until the cause for the trouble, which usually is to be found in an incorrect selection of the distances of the measuring nozzles from the objects that are to be measured, i.e. from the workpiece and/or from the grinding worm, is rectified. The measuring process in this case is repeated continuously. During depression of a started key for the beginning of the working cycle, the sensor unit may be moved automatically into the measuring zone, i.e. between the grinding worm and the workpiece, whereby the position of the three parts mentioned must be established at the first workpiece. The swing-out of the sensor unit from the measuring zone and the introduction of the grinding worm into the workpiece to be processed may take place automatically on command of above-mentioned counter. An embodiment of an apparatus for implementing the described process in connection with positive electronic movement control of a tooth bevel grinder will be explained subsequently on the basis of FIGS. 3 and 4. FIG. 3 illustrates as components of the grinder apparatus the above-mentioned electronic positive movement control 1 including a grinding worm 2 and of a gear-workpiece 3 to be processed, a measuring structure 20 and an electronic control system 50 of the present arrangement for the automatic engagement of the grinding worm 2 into the tooth spaces of the workpiece 3 to be ground. The grinding worm 2 is driven by an electric motor 4. A shaft encoder 5 for determining the rotary angle of the grinding worm 2 is disposed on its shaft, the output pulses of which are fed to a divider 6. The outlet of the divider 6 is connected to the input of an anti-coincidence detector unit 8. The workpiece 3 is actuated by a stepping motor 9 on the shaft of which an additional shaft encoder 10 is disposed. The output of the shaft encoder 10 is connected to an additional input of the anti-coincidence unit 8. Two outputs of the anti-coincidence unit 8, delivering signals with different signs are connected to a balance counter 11, the output signal of which is fed to a regulator 12. The control signal produced by this device is fed via a power amplifier 13 to the stepping motor 9 for the controlled drive of the workpiece 3. The measuring structure 20, provided in addition to the known positive movement control 1, includes a sensor unit 21 having a pneumatic differential pressure gauge, known per se, and a pair of nozzles for measuring the grinding worm 2 and the workpiece 3. Each of the two pairs of nozzles contains an adjustable reference nozzle 24, 25 and a measuring nozzle 22, 23. The sensor unit 21 is attached to a bracket 26 which may be swung in or out by means of which it is moved into the measuring zone between the grinding worm 2 and the gear-workpiece 3 upon a command for starting the processing action. After a completed measuring and correcting operation, the bracket 26 together with the sensor unit 21 attached to it, is given the command for swinging out of the measuring zone by a measuring counter 57, described later, which counts and monitors the number of the teeth of the workpiece and spaces of the grinding worm by which the mean value for the corrective shifting V M is determined. As a result of swinging the bracket 26 out, the command signal for moving in the workpiece 3, now being in the correct position, is given simultaneously to the grinding worm 2. A swing actuator 27 for swinging the bracket 26 in and out is provided. This may be a pneumatically operated rotary actuator the construction of which need not be described here as a number of such devices are readily commercially available and quite well known. The electronic control system 50 is connected with the above-described units via several lines. One connecting line 101 is connected to the swing actuator 27 for swinging the holder 26 in and out and delivers a starting pulse to the control system 50 after the swinging in of the holder 26. Another connecting line 141 is likewise connected with the swing actuator 27 and delivers a command signal for swinging out of the holder 26 to the former. Two connecting lines 104 and 113 are connected to the sensor unit 21 and feed the measuring signals of the measuring nozzles 23 or 22 to the control system 50. One connecting line 127 is connected with the output of the shaft encoder 10 of the drive for the workpiece 3. Finally two more connecting lines 136 and 137 are connected with the anti-coincidence unit 8, and feed polarity-separated, i.e. directionally separated correctional signals to it. FIG. 4 shows a block circuit diagram of the electronic control system 50 of FIG. 3 in which the input and output lines are designated in correspondance with FIG. 3 and are indicated with large arrows. FIG. 5 is a flow diagram and FIG. 6 a detailed logic schematic of the system of FIG. 4. The following explanation of this circuit diagram is made on the basis of the description of functions in the course of a measuring and correcting process. By way of a starting pulse which is fed from the grinder via the line 101 (FIG. 3), a starting flip-flop 51 is set, with which the arrangement is actuated or the measuring and correcting process begun. From the starting flip-flop 51, the starting signal is fed via line 102 and line 103 and branched off from it to a first logic unit 52 which is provided for the production of corrective pulses and also via the same line to a measuring counter 57 and a shift counter 59, both described below, as a reset-to-zero signal. The same signal is also coupled to line 102 of a logical AND-gate circuit 151 for its control. As soon as the starting point 0 of the first space L S of the grinding worm has been detected by the pertinent measuring nozzle 23 upon passage of the toothing of the grinding worm, a corresponding pulse signal which represents the reference point 0 of the measurement (FIGS. 1A to 1H), is delivered on line 104. This signal reaches the line 105 via a monostable circuit 63, which transforms the signal to a shorter pulse, and the set input S of a measuring flip-flop 53 via the opened gate of the logical AND-gate circuit 151 as well as the line 106, the setting inlet S of a space-flip-flop 54 of the grinding worm via the line 104', and the reset input L, of a tooth-end flip-flop 55 via a line 107, branched off from line 105. A by-pass line 104" connects line 104 to the reset input L of the flip-flop 54 so as to reset that flip-flop as soon as the signal on line 104 disappears, thus indicating the beginning of a tooth of the grinding worm. From the measuring flip-flop 53, the pulse signal representing the beginning of the space of the grinding worm is fed via a line 108 and a line 109, branched off from the former, to a second logic-unit 56 for measuring pulses. Simultaneously, the pulse signal is fed via the line 108, another logical AND-gate circuit 152 and a line 112 to the measuring counter 57. The counter 57 counts the number Q of workpiece teeth, which may be adjusted by way of which the measurements for forming the mean value for the corrective shifting V M are carried out. The space flip-flop 54 is connected with the logic-unit 56 for the measuring pulses via a line 110. A line 111, branched off from line 110, leads to the logical AND-gate circuit 152. Whenever now a signal, which indicates a space between two workpiece teeth, is delivered by the measuring nozzle 22, which is assigned to the workpiece, to the line 113 (FIG. 3), then this signal is fed via a monostable circuit 64 and a line 113' to the setting inlet S of the tooth-end flip-flop 55 and also via a line branched off from line 113, which includes an inverter 114, and a line 114', to the logic-unit 56 for the measuring pulses. From the set tooth-end flip-flop 55, a line 115 leads to another logical AND-gate circuit 153 and from here via a line 116 to the setting input S of an error flip-flop 58 which serves for monitoring whether or not any one or two workpiece teeth are registered within a measuring cycle. The cycle always last from the beginning of the space of the grinding worm to the beginning of the next space of the grinding worm. Furthermore, the output of the tooth-end flip-flop 55 is connected with the logic unit for the measuring pulses via a line 117 branched off from line 115. In order to determine whether more than one workpiece tooth is being registered within the measuring cycle mentioned, the pulse signals of the workpiece tooth-end are fed to the error flip-flop via the line 118 as well as via the logical AND-gate circuit 153, by-passing the tooth-end flip-flop 55, whereby the error flip-flop 58 is set simultaneously with the arrival of the pulse signal. As long as no pulse signal which indicates the end of the workpiece tooth is delivered via the monostable circuit 64 by the measuring nozzle 22, which is assigned to the workpiece, the tooth-end flip-flop 55 remains reset because of the pulse signal initiated from the starting point of the space of the grinding worm. In this period, therefore, an additional logical AND-gate circuit 154 is opened via a line 119. The pulse signals representing the beginnings of spaces of the grinding worm are fed to an additional set input of the error flip-flop 58 by line 121, branched off from the line 107, with which the tooth-end flip-flop 55 is by-passed, via the AND-gate circuit 154 and a line 120, where the pulse signals cause its setting. Whenever no tooth or two teeth have been registered by the error flip-flop 58 within the measuring cycle, then the measurement is wrong, i.e. a shift-counter 59, which will be described subsequently, is reset via a line 122, the measuring flip-flop 53 is reset via a line 123 branched off from line 122, and the measuring counter 57 is reset via a line 124 branched off from line 123, so that the measurement may start again in a subsequent measuring cycle. The error flip-flop 58 itself is reset via a line 125, branched off from line 22 and which leads to a delaying unit 60, and from there via a line 126, which is connected with the reset input L of the error flip-flop 58. The workpiece pulses with the frequency f W , produced by the shaft encoder 10 of the workpiece 3, are fed via line 127 (FIG. 3) to a frequency divider 61, by which a division of said frequency F W is accomplished by the adjustable factor Q which may be an integer to 1 to n. Then measuring pulses with the measuring frequency f M =f W /Q are fed from this frequency divider 61 via a line 128, and with half the measuring frequency f M /2 via a line 129 to the logic unit 56 for the measuring pulses. The shift counter 59 with its two inputs, marked by + and - for plus measuring pulses or minus measuring pulses, is connected to two outputs of the logic unit 56 for the measuring pulses via lines 130 and 131. The generation of measuring pulses, arriving on the lines 128 and 129 in the logic-unit 56, to the shift counter 59, takes place according to the signals present on the additional inlet lines 110, 114, 117 of the logic-unit 56, in accordance with the following logic table of the logic unit 56 which corresponds to the previously given counting pattern of measuring pulses. __________________________________________________________________________ Measurement ##STR1## ##STR2## ##STR3## tooth end - FFtooth__________________________________________________________________________ and Space ##STR4## ##STR5## ##STR6##SS ##STR7## ##STR8## ##STR9## ##STR10##__________________________________________________________________________ In this table: SS: stands for "grinding worm" tooth: a tooth of the workpiece is detected, i.e. a signal is present on line 114' (in view of inverter 114) tooth: there is no tooth of the workpiece detected, i.e. no signal is present on line 114' (in view of inverter 114) tooth-end-FF: the tooth-end flip-flop 55 is set, and a signal is present on line 117 tooth-end FF: the tooth-end flip-flop 55 is reset and there is no signal present on line 117 space: the space flip-flop 54 is set, and there is a signal present on line 110 space: the space flip-flop 54 is erased and there is no signal present on line 110 f M →VZ etc.: measuring pulses with the frequency f M are fed to the shift-counter VZ via the line 130 (+) or 131 (-). The plus and minus measuring pulses algebraically are summed within each measuring cycle which lasts, as already mentioned, from the starting point 0 of a space L S of the grinding worm to the starting point of the next space L S of the grinding worm. The summed pulses are fed from the shift counter 59 as the content of the counter J Z via a line 132 to a decoder 62, whereby in the case J Z >0 or J Z >0, i.e. in the case that the content of counting is different from 0, the counter content J Z is forwarded via a line 133 to the unit 52 for the corrective pulses. The case J Z =0 will be explained below. Upon receipt of the "end of measurement" signal by the counter 57 which is delivered via a line 134 to the corrective pulse logic-unit 52, after passage of Q tooth-spaces, corrective pulses are produced by the logic-unit 52 using pulses with the correction frequency f K from the frequency divider 61 via a line 135. The value of the frequency f K of the corrective pulses is fixed with due consideration of the dynamics of the correcting arrangement on the grinder for tooth flanks, since the latter must be able to obey the corrective pulses. In practice, the frequency may be about 1000 Hz. The formation of the mean value takes place automatically during the counting of the measuring cycles, since division by the number of measuring cycles required for the formation of mean values has been taken into consideration during summation since the division of the frequency f W of the workpiece pulses takes place by the factor Q, i.e. the number of workpiece teeth. Since the number of teeth of the workpiece is considerably smaller than the number of pulses of the workpiece, this formation of mean values is sufficiently accurate. Negative corrective pulses, which cause a forward movement of the workpiece 3, are introduced from the logic unit 52 for the corrective pulses on a line 136 and positive corrective pulses, which cause a backward directed rotary movement of the workpiece 3, on the line 137 into the existing control system of FIG. 3 of grinding worm 2 and workpiece 3. The negative corrective pulses are fed via a line 138, branched off from line 136, and the positive corrective pulses via a line 139 branched off from line 137, to the positive or negative input of the shift counter 59 for the purpose of resetting the shift counter by pulses up to 0. The logic-unit for the corrective pulses operates according to the following logic pattern. For the start and end of the measurement (signals on lines 103 and 134): J Z >0 (starting signal on line 133). The shift counter 59 then counts downward with the correction frequency. For J Z >0 (no starting signal on line 133), the shift counter 59 counts upward with the correction frequency. Whenever the counter content determined in the shift counter 59 is J Z =0, then a corresponding signal is delivered by the decoding unit 62 via the line 138 to the logical AND-gate circuit 155. Whenever such a signal originates within a single measuring cycle, that is within a tooth space, then nothing at all will happen. The AND-gate circuit 155 releases the signal for resetting the starting flip-flop 51 only in case of the simultaneous arrival of the "end of measurement" signal fed in on a line 139, branched off line 134, via a line 140, which is connected to the reset input of the starting flip-flop 51. The "end of measurement" signal, however, will be delivered by the measuring counter 57 only after complete passage of the selected number of Q tooth spaces or number of Q tooth spaces adjusted by the measuring counter 57 controlled by the error flip-flop 58. After the "end of measurement" signal however the shift counter 59 is reset to zero by the corrective pulses as described earlier so that a corresponding signal is fed into the logical AND-gate circuit 155 via line 138. The "end of measurement" signal is fed to the swing actuator 27 for the swinging in and out of the holder 26 on which the sensor unit 21 is attached via the line 141 and branched off from line 139. The resetting of the shift counter 59 preferably takes place as a result of the corrective pulses during the swinging out operation since the electric, positive action control, explained on the basis of FIG. 3, is sufficiently fast, to accomplish any correction during the swinging out. Whenever another correcting arrangement than an electric one is provided, then the two processes must be staggered in time. After the swinging out, the actual grinding process, i.e. the moving in of the grinding worm 2 into the workpiece 3 which now is in the correct position in regard to the former may be started. With regard to FIG. G, the integrated circuit number specified are all Texas Instruments, Inc. types.

The present invention relates to an apparatus and a process for a gear processing machine operating according to the screw rolling process principle and with positive control of the movement of a rotating tool in the prearranged toothing of the workpiece rotating with respect to the tool.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for handling wellhead structures, and especially to a method for transporting underwater wellhead assemblies to an offshore jack-up drilling rig or oil-production platform and installing it on the ocean floor. 2. Description of the Prior Art In recent years it has become desirable to use offshore jack-up drilling rigs or barges from which to drill wells in marine locations. The jack-up drilling rig consists of a buoyant platform which is provided with a number of legs extending through the platform vertically and can be moved up and down in a vertical line by jacking or lifting systems consisting of the jack arranged on a longitudinal side of the leg and the pinion mounted on the platform to engage with the pinion. In the rig of this type which will be referred to as a "jack-up-rig", the legs are lifted up out of the surface of the water and the buoyant platform is usually towed to a preselected offshore drilling location by, for example, a tug boat or boats, the legs are then lowered down to the ocean floor and the platform is raised up above the surface of a body of water so that it can be fixed and supported on the ocean floor. When carrying on a multi-well drilling operations in the ocean, a subsea template having a plurality of receptacles therein is set on the ocean floor, and holes are drilled through some of these receptacles. In drilling oil and gas wells in the ocean floor in depths up to approximately 90 meters, the jack-up-rig may usually be operated by using a subsea wellhead assembly and a surface blowout preventer extending above the surface of a body of water for safety and reliability. However, in drilling the ocean floor in depths of water greater than about 120 meters or under hostile environmental conditions such as strong wind and severe sea conditions, the jack-up-rig must employ a subsea blowout preventer and a subsea wellhead assembly. In practice, these wellhead assemblies are positioned in depths of water greater than the depth at which a diver can safely and readily work. Furthermore, the base member which is a horizontally-extending frame called a "template" is for example, about 24 meters in length, about 6 meters in width and more than 140 tons in weight. Such a heavy and cumbersome structure is impossible to carry or transport on the vessel type or semi-submersible drilling barge. Consequently, the template has been handled by, for example, crane barges or derrick cargo barges separate from the drilling barge. This is very expensive and requires a number of means for lowering the template down to the ocean floor and bringing the drilling barge to its correct position with respect to the anchored template. OBJECTS OF THE INVENTION In the light of the above and the necessity for using the jack-up-rig under a severe condition of deep sea, a main object of the present invention is to provide a method for handling an underwater wellhead assembly by the jack-up-rig. It is another object of the present invention to provide a method for mounting and carrying an underwater weelhead assembly and a template on the jack-up-rig. It is a still further object of the present invention to provide a method for installing a wellhead assembly by the jack-up-rig on the ocean floor at a preselected drilling location. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of the present invention will be understood from the following description taken with reference to the drawings, wherein: FIG. 1 is a schematic perspective view of the jack-up-rig for carrying out a method for the invention; FIG. 2 is a plane view of a template which is a part of a underwater wellhead assembly; FIG. 3 is a schematic view of a blowout preventer to be mounted on the template; and FIG. 4 through FIG. 8 are respectively a schematic view illustrating steps for carrying out the method of the invention. DETAILED DESCRIPTION Referring now to the drawings, a schematic diagram of FIG. 1 shows a drilling platform or barge of a jack-up-rig type which is generally designated by the reference numeral 10 which is provided with at least three legs 12. Each leg 12 is extended vertically through the platform 10 provided with a cantilever working deck 14 which may be slid horizontally along it and projected therefrom. Mounted on the cantilever working deck 14 is a tower 16 provided with several pieces of equipment such a drilling machines and winches or draw works. The legs 12 of the rig 10 are lifted up from the surface of a body of water so that the plaltform 14 may buoy it up and may be towed by tug boats to a preselected drilling location at which each of the legs 12 is lowered down to the ocean floor, and then the platform 14 is lifted up to a desired height from the surface of water, the cantilever working deck 14 being moved from its original position to the outboard of the platform for the desired drilling operations. In carring out drilling operations using the jack-up-rig 10, a template 20 must be positioned on the floor of the sea in the same manner as with other type of barges. According to the present invention, the template 20 provided on the shore or quay 30 for the purpose of placing it on the ocean floor is carried on the platform 10 and transferred therewith from the quay 30 to a preselected drilling location. As shown in FIG. 4, to mount the template 20 on the platform 10, it is brought alongside the quay 30 at which the template 20 is prepared, the legs 12 of the platform 10 are lowered down to the ocean floor, and the platform 10 is lifted up to a desired height from the surface of a body of water. Then the cantilever working deck 14 is extended from the stern of the platform 10 to over the template 20 lying on the quay 30. The template 20 is lifted up to the underside of the cantilever deck 14 by any suitable means such as winches and cables. Then, as shown in FIG. 5, the cantilever working deck 14 carrying the template 20 is returned back from the extended position to its original position within the stern of the platform 10, and the template 20 may be housed therein or in the main deck, the legs 12 being lifted up from the ocean floor so that the platform 10 may be floated on the surface of a body of water and towed by boats to a preselected drilling location. When the platform 10 carrying the template 20 thereon has arrived at the preselected drilling location, the legs 12 are lowered down to the ocean floor and then the platform 10 is lifted up to a desired height from the surface of a body of water. Then the cantilever working deck 14 is extended from the stern of the platform 10 together with the template 20 so that the template may be set into just above a desired position to be fixed on the ocean floor. To keep the template in the cantilever or on the main deck, it may be stored without using overdimensional out fittings such as wire guide posts and overhang guide posts. Such outfitting works may be carried out when the template is located at a main deck level on the way to lowering it to the ocean floor. After the template 20 has been moved down to a desired position, it is leveled through template leveling receptacles and guide posts and the guide posts have been piled through guide post receptacles 24. Either a conductor pipe is fixed to the ocean floor for surface drilling or a subsea blowout preventer BOP is carried on the template 20 for subsea drilling. According to the method of the invention, as is obvious from the foregoing, the transportation and installation of the template 20 can readily be made without using crane barges or derrick cargo barges which are very expensive. Further, according to the present invention, the subsea blowout preventer BOP can be installed for subsea drilling operation. While a preferred embodiment has been desacribed, variations thereto will occur to those skilled in the art within the scope of the present inventive concepts which are delineated by the following claims.

A method for handling an underwater wellhead assembly by means of an offshore jack-up drilling rig or platform wherein the wellhead assembly is prepared on the shore or quay and is carried on the drilling rig to a preselected drilling location and lowered down therefrom to the ocean floor.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of portable personal computers and more particularly to an insulating board or heatshield used in connection with a portable personal computer to shield the user's lap from heat generated by the computer. 2. General Background and State of the Art The proliferation of portable personal computers, or laptop computers, is well documented. Laptop computers are used by business travelers to perform virtually all of the tasks enabled by desk top computers during previously unproductive hours traveling on airplanes, in hotels, and generally away from the office. Laptops also offer an alternative to bulkier, space consuming desk top models, with the opportunity to readily take the laptop to remote locations such as lectures, business meetings, or the like, and also to bring one's computer home in the evenings to continue working on projects. The reduction in the size and weight of today's laptops render them indispensable to travelers and business people around the world. Laptop computers, like desk top computers, include a processing unit or chip that performs calculations used in the operation of the laptop. The processing unit generates a substantial amount of heat, and as processors grow more powerful and faster (in the multi-Gigahertz range) the amount of heat that the chips generate continues to increase. In most desktop computers, there are fans, heat sinks and adequate airspace to dissipate the heat generated by the processor. However, in a laptop computer there is very little room for large fans or open airspace, so heat is transferred through the underside of the computer where it comes in contact with the user's lap. The processors can produce up to 100 watts per square centimeter—the equivalent heat generated by a light bulb, and temperatures can easily reach 115° F. or more. The push for smaller and lighter laptop computers exacerbates the problem of heat dissipation. The heat problem is a byproduct of consumer demand for smaller, faster computers with reasonable battery life because large fans and extra airspace require larger units with reduced battery life. As a result, the underside of a laptop computer is notorious for being very warm or even hot to the touch when it has been running for a period of time. Left unchecked, the heat build up of the laptop computer is transferred to the user at the point of contact where the laptop rests on the user's lap. As the laptop heats up, the build up of heat may become uncomfortable and can even result in pain. In this event, the user must endure the discomfort or discontinue operation of the laptop to allow the unit to cool down. Once cooled down, the laptop will once again begin to heat up to the point where discomfort requires another shutdown to allow further cooling. This repeating pattern of working followed by forced breaks to allow the computer to cool down is unproductive and can be disruptive, not to mention the discomfort involved. As a result, others have attempted to solve this problem through various methods. For example, a product marketed by Macally U.S.A. of Irwindale, Calif. called the “IcePad” comprises a two panel hinged device that allows air to circulate between the laptop and the user. However, the Icepad is heavy and bulky—two significant shortcomings when traveling. In addition, the Icepad has grooves or channels for airflow along its bottom surface that create an uneven surface, and such uneven surfaces can become uncomfortable to the user after prolonged use. Also, U.S. Pat. No. 6,474,614 to MacEachern discloses a heat dissipating laptop support comprising a trapezoidal stand with stackable risers to allow air to pass through while tilting the laptop toward the user (see FIGS. 6 and 7). The laptop sits on a column of spacers that can adjust in height depending upon the number of spacers used. However, one risk in this device is that the spacers may become uncoupled and dislodged, causing the laptop to fall, and the device is ill-suited for adjusting to variable sized laptops. In addition, U.S. Patent Publication No. US 2003/0080264 to Helmetsie et al. discloses a laptop support with Velcro® fasteners that include louvers to circulate air between the laptop and the support. These louvers define grooves on the underside of the support that bear against the user and may become uncomfortable over time. The iGo ErgoStand offered by iGo® products (www.igo.com) is a notebook stand that claims to “raise(s) your notebook for a more comfortable typing position and viewing angle,” and “increasing the airflow around your system allows it to run cooler.” The device is designed for resting on a table rather than a user's lap, and the large opening in the ‘X’ pattern will not shield the laptop heat from the users lap if the Ergo Stand should be placed between the laptop computer and the user's lap. Small rubber pads at the end of the four corners are designed to mate to the bottom plastic surface of the laptop. They are not large enough to mate with the friction pads on the bottom of laptops that are positioned on various locations based on the size and make of the laptop. Also, the shape and plain shell structure (the bottom of the Ergo Stand is hollow) does not offer a large bending moment of inertia and hence would not likely offer sufficient structural support. Other devices are known for supporting a laptop to provide a stable platform, but none of the prior art devices are well suited for the combination of heat dissipation and comfort. INVENTION SUMMARY The present invention is directed to a lightweight composite thermal insulating board (“heatshield”) for a laptop computer that shields heat from the user using multiple layers each adapted to provide rigidity and/or thermal protection while providing a comfortable contact surface for the user. In one embodiment, the composite insulating laptop board of the present invention comprises a first layer of thin plastic that gives the board a smooth, hard upper surface. The hardened plastic top layer preferably includes an underside comprising ribs beneath the surface that adds rigidity and stiffness to the board. A second layer of plastic encloses the ribs to create a pockets of air therebetween which act as an insulation layer, while this second plastic layer further solidifies the board. Alternatively, the ribs may be open at the sides to permit the circulation of air between the ribs. Underneath the second plastic layer can be an insulating material such as a foam, cloth, expanded polymeric material, or other suitable lightweight insulating material, to further inhibit heat from passing through the board. Alternatively, the insulating material can be sandwiched between the first and second layers rather than adhered to the bottom surface of the second layer. In addition to the composite structure described above, the insulating laptop board can be configured on its upper surface with integral risers extending diagonally to the board's corners. The risers are adapted to support cooperating footpads on the base of a laptop to establish an air gap between the underside of the laptop and the upper surface of the board. Employing a diagonal or “X”-shaped arrangement of the risers allows the present invention to accommodate a variety of laptop sizes. Further, the integral nature of the risers eliminates any possibility that the risers can become dislodged or separate from the board. The continuous surface can be created with various manufacturing methods such as injection molding that creates a smooth, uninterrupted surface with varying elevations. To aid in supporting the laptop on the risers, each riser may also include an upwardly projecting wall that acts as a stop or catch. By strategically placing the footpads of the computer adjacent the walls of the risers, the laptop may be confined on the risers to resist sliding or shifting of the laptop on the board's upper surface during use. In addition, the risers may be equipped with a non-slip surface to engage the footpads of the laptop and prevent the laptop from sliding when in use. The invention thusly comprises a lightweight, sturdy, thermally insulating composite laptop board with a small profile and no moving parts. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevated, perspective view of an embodiment of the present invention; FIG. 2 is a perspective view of a laptop resting on the embodiment of FIG. 1 ; FIG. 3 is an enlarged, close-up view of a riser of the embodiment of FIG. 1 ; FIG. 4A is a lower perspective view of the first layer of the embodiment of FIG. 1 ; FIG. 4B is a bottom view of the first layer of the embodiment of FIG. 1 ; FIG. 4C is a top view of the first layer of the embodiment of FIG. 1 ; FIG. 4D is an elevated perspective view of the first layer of the embodiment of FIG. 1 ; and FIG. 5 is an exploded view of the composite layers of the embodiment of FIG. 1 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment 10 of the heat shielding laptop board of the present invention is shown in FIGS. 1 and 2 , which disclose a rigid, planar rectangular composite board having a first layer 12 with short platforms or steps, hereafter “risers”, 14 diagonally extending to each corner in an “X”-shaped configuration. The risers 14 may be hollow so as to form a cavity therebelow, or the risers may be solid throughout. Each riser 14 may include inclined sides 16 located within the interior area 18 of the first layer 12 and vertical edges 20 along the board's perimeter. The flat top surface 22 of each riser 14 may be configured to be parallel to each other riser top surface 22 defining a second horizontal plane or elevation 24 parallel to the first horizontal plane or elevation 26 of the first layer 12 . Alternatively, the top surfaces 22 and/or interior surface 18 may be angled with respect to each other for a more ergonomic-friendly positioning of the laptop, or the surfaces 22 may be oriented at different heights to allow for improved typing positions. Each top surface 22 of the risers 14 is preferably fitted with a non-slip material 28 adhered thereto, such as a rubber or polymer material used on the bottom surface of common mouse pads or other frictional surface. Alternatively, the top surface 22 may be made of a polymer material with non-slip surface characteristics. The risers 14 include a rounded first end portion 30 proximal to the center area 32 of the board 10 , and a second corner shaped end portion 34 distal to the center area 32 of the board 10 and conforming with the corners of the board as shown in FIG. 1 . Between the proximal end 30 and the distal end 34 of the risers 14 , the beveled sides 16 may extend parallel to each other. Of course, the shape of the risers 14 , their position on the board 10 , as well as the shape and alignment of the beveled sides can be varied for numerous configurations without deviating from the scope of the invention. Risers 14 are shaped and dimensioned such that the bottoms of various sized lap tops can rest on surfaces 22 of risers 14 . Each riser 14 can also include an upstanding wall or stop member 36 disposed on the flat top surface 22 along an outer peripheral edge coinciding with the longitudinal sides 38 of the board 10 , where a portion 40 of wall member 36 angles inwardly from the outer peripheral edge and along the flat top surface 22 to bound a portion 42 of the perimeter of the riser's upper surface 22 . The walls 36 cooperate to act as a stop for the laptop's foot pads (not shown) that project downward from underside of laptop 44 . The angle of the inwardly directed portion 40 of the walls 36 is adapted to account for the most standard sizes of laptop computers, such that the footpads of the various computers 44 will bear against the walls 36 , further preventing the laptop from shifting or sliding on the surface 22 of the riser 14 . FIG. 3 illustrates an enlarged view of a riser 14 of the embodiment described above. As shown in FIG. 2 the risers 14 provide for an air gap 58 between the computer's bottom surface 60 and the upper surface 18 of board 10 for heat dissipation. FIGS. 4 a–d illustrate several views of the top layer 12 of board 10 . As shown in FIGS. 4 a–d , the top layer 12 is preferably comprised of a thin plastic shell formed with the integral risers 14 on the upper surface 46 and a series of panels or ribs 48 on the underside 50 . The risers 14 increase the bending moment of inertia of the first layer 12 and thus add stiffness to the board 10 . The ribs 48 of the underside 50 portion of top layer 12 serve a dual purpose. The first purpose is to add stiffness to the overall board structure to prevent bending or flexing. The presence of the ribs increases the rigidity of the board. The second purpose is that the ribs form compartments that define air pockets therebetween, and the air pockets serve as an insulating mechanism to resist the passage of heat through board 10 . Referring to FIG. 5 , air is a well-known insulator and the trapped air within the composite board between the ribs 48 provide a barrier for transmitting heat across the board 10 . As shown in FIG. 5 the air is trapped in a checkerboard pattern of air pockets. Other patterns such as a honeycomb pattern can be employed. In another embodiment, the ribs 48 do not form sealed compartments but rather the compartments formed by the ribs open at the vertical sides 38 of the first layer 12 allowing ventilation of the board's interior. In still another embodiment ribs 48 are not present. Instead, the sides 38 seal the underside 50 to form an insulating cavity between top layer 12 and second layer 52 . The insulating cavity can also be a vacuum, gas filled, or can be fully or partially filled with insulating material such as insulating foam materials. Likewise, the ribbed embodiment can be similarly insulated. The second layer 52 of board 10 may be a thin plastic counterpart shell to the first layer 12 for enclosing the ribs 48 . The second layer 52 of the board 10 serves as an additional stiffening member in addition to enclosing the ribs 48 of the first layer 12 akin to a composite sandwich structure. In one embodiment, a thermal insulating third layer 54 is disposed beneath the second layer 52 as shown in FIG. 5 . Layer 54 can be formed of neoprene, polymer, foam, cloth, or other insulation material. When the board 10 is placed on the user's lap, layer 54 can also serve as a frictional surface to resist slippage of the board when in use. Layer 54 can also be formed of a material that is comfortable to a user's bare skin and can be formed of a material that breathes or wicks away moisture. As shown in FIG. 5 the air is trapped in a checkerboard pattern of air pockets. Other patterns such as a honeycomb pattern can be employed. Alternatively, layer 54 can be omitted or sandwiched between the first and second layers 12 and 52 . With the insulating layer 54 incorporated either internally or externally, the board 10 includes two layers 12 and 52 that cooperate to form the board 10 , a layer of air pockets 50 defined by the ribs 48 , and an insulating layer 54 that inhibits heat transfer across the board and provides a soft contact surface for the user. The vertical sides 38 of the first layer 12 extend around the periphery of first layer 12 and when joined with second layer 52 form a common periphery. As discussed above, the present invention can include three or more insulating mechanisms that inhibit heat transfer across board 10 between the laptop and the user, in addition to the shell formed by the first and second layers 12 and 52 . The three mechanisms include: the air gap 58 formed by the positioning of the laptop 44 on the risers 14 ; the air pockets 50 between the first layer 12 and second layer 52 of board 10 defined by the ribs 48 ; and an insulation layer 54 either sandwiched within the board between the first and second layers 12 and 52 , or secured to the underside of the second layer 52 . The insulating layer may also comprise a thin film of insulating material deposited on second layer 52 . In addition, a laptop positioned on the risers 14 will be inhibited from sliding or shifting when in use due to a non-slip surface 28 on the top surface 22 of each riser. Further, upstanding wall members 36 on the peripheral edge of each riser and extending inwardly along a riser serve as a stop or catch to secure the laptop on the board and prevent movement of the laptop. The positioning of the risers and particularly the upstanding wall members 36 allow for variable sized laptops to be used with a single embodiment of the invention. While the specification describes particular embodiments of the present invention, those of ordinary skill can devise variations of the present invention without departing from the inventive concept. For example, it should be appreciated that the board 10 can be made of various materials including polymers and composites. Further, the first layer 12 may be made of the same material as the second layer 52 , or the two layers may be constructed from two different materials. Moreover, while the board 10 is illustrated in FIG. 1 as having a rectangular shape, other shapes that conform to the shape of various laptops may be employed. Other departures from the description above will be readily apparent to one of ordinary skill in the art, and the scope of the invention is intended to include all such variations.

The present invention is directed to a laptop platform for resting a laptop computer on a user's lap; the platform comprising a composite structure having risers to establish an air gap between the platform and the laptop. In one embodiment the platform is further configured with upper and lower layers including a plurality of ribs extending therebetween to define a pocket or pockets of air. The air pockets act as a second insulating source while the ribs aid in stiffening the platform. Further, a designated insulation material may be is adhered to the lower surface of the platform to create a third, separate barrier to heat transfer across the platform.

[0001] This application claims the benefit of the Korean Application No. P2001-83399 filed on Dec. 22, 2001, which is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display and a fabricating method thereof enabling to improve an opening ratio of the liquid crystal display by modifying a structure of a thin film transistor. [0004] 2. Discussion of the Related Art [0005] Generally, a liquid crystal display includes a lower substrate having thin film transistors and pixel electrodes arranged thereon, an upper substrate having color filters for realizing colors and common electrodes, and liquid crystals inserted between the upper and lower substrates. In this case, light transmittance of the liquid crystals varies in accordance whether a voltage is applied thereto or not so as to display an image. [0006] Namely, on the lower substrate are formed a plurality of gate lines arranged in one direction so as to leave a predetermined interval from each other, a plurality of data lines arranged in a direction perpendicular to the gate lines with a predetermined interval from each other so as to define matrix type pixel areas, respectively. A plurality of pixel electrodes are formed in the pixel areas, respectively. And, a plurality of thin film transistors are formed at intersections between the gate and data lines so as to apply data signals of the data lines to the corresponding pixel electrodes in accordance with signals of the gate lines, respectively. [0007] On the upper substrate are formed black matrix layers cutting off light from portions corresponding to the gate lines, data lines, and thin film transistors on the lower substrate, R, G, and B color filter layers at portions corresponding to the pixel areas, respectively, and common electrodes on the color filter layers, respectively. [0008] Since the black matrix layers are formed to cut off light from the portions where the thin film transistors are formed in the general liquid crystal display, an opening ratio is reduced corresponding to the portions where the thin film transistors are formed. [0009] A constitution of a thin film transistor in a liquid crystal display according to a related art is explained as follows. [0010] [0010]FIG. 1 illustrates a layout of a thin film transistor in a general liquid crystal display. [0011] Namely, a gate line 1 having a gate electrode 1 a is arranged in one direction with a predetermined interval from other gate lines on a substrate(not shown in the drawing), and a gate insulating layer(not shown in the drawing) is formed on an entire surface. A semiconductor layer 3 as an active layer of a thin film transistor is formed like an island on the gate insulating layer over the gate electrode 1 a, and a data line 2 having a source electrode 2 a is arranged on the gate insulating layer with a predetermined interval in a direction perpendicular to the gate line 1 so as to define a pixel area. In this case, the gate and source electrodes 1 a and 2 a are formed at the pixel area at an intersection between the gate and data lines 1 and 2 , and the source electrodes 2 a extends from the data line 2 so as to be overlapped with the semiconductor layer 3 . [0012] And, a drain electrode 2 b is formed on the semiconductor layer 3 at a side opposite to the source electrode 2 a so as to complete a thin film transistor(TFT). Besides, a pixel electrode 4 is formed in the pixel area so as to be connected to the drain electrode 2 b. [0013] Unfortunately, the thin film transistor in the general liquid crystal display has the following disadvantages or problems. [0014] First, the thin film transistor is formed at the specific area in the pixel area, thereby reducing an opening ratio of the liquid crystal display. [0015] Second, since the source electrode extends from the data line so as to be overlapped with the gate electrode, the parasitic capacitance formed between the gate and source electrodes, is not uniform for various reasons including misalignment during fabrication which causes flickering of the liquid crystal display. SUMMARY OF THE INVENTION [0016] Accordingly, the present invention is directed to a liquid crystal display and a fabricating method thereof that substantially obviates one or more problems due to limitations and disadvantages of the related art. [0017] An object of the present invention is to provide a liquid crystal display and a fabricating method thereof enabling to improve an opening ratio of the liquid crystal display by placing a channel region of a thin film transistor on a gate line as well as reduce a parasitic capacitance Cgs between the gate and source electrodes and another parasitic capacitance Cgd between the gate and drain electrodes. [0018] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. [0019] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a liquid crystal display according to the present invention includes a gate line formed on a substrate in one direction with a predetermined interval from other gate lines, a data line formed in a direction perpendicular to the gate line so as to define a pixel area, a thin film transistor formed on the gate line at an intersection between the gate and data lines, and a pixel electrode formed in the pixel area. [0020] Preferably, the thin film transistor includes a semiconductor layer formed over the gate line at the intersection between the gate and data lines wherein the gate and data lines are used as gate and source electrodes, respectively and a drain electrode formed over the gate line across a portion of the semiconductor layer confronting the data line. [0021] More preferably, the semiconductor layer is further formed under the data line. [0022] More preferably, the pixel electrode extends to be connected to the drain electrode. [0023] Preferably, a portion of the gate line where the thin film transistor is formed is wider than the remaining portion of the gate line. [0024] Preferably, gate and source electrodes of the thin film transistor does not protrude from the gate and data lines, respectively. [0025] In another aspect of the present invention, a method of fabricating a liquid crystal display includes the steps of forming a gate line on a substrate, depositing a gate insulating layer on an entire surface of the substrate having the gate line formed thereon, forming an island-like semiconductor layer on the gate insulating layer over the gate line, and forming a data line on the gate insulating layer in a direction perpendicular to the gate line so as to be overlapped with one side off the semiconductor layer and forming a drain electrode over the gate line so as to be overlapped with the other side of the semiconductor layer. [0026] Preferably, the method further includes the steps of forming a passivation layer on an entire surface of the substrate so as to have a contact hole exposing the drain electrode and forming a pixel electrode in the pixel area so as to be connected to the drain electrode through the contact hole. [0027] Preferably, a gate electrode of a thin film transistor failing to protrude from the gate line is not formed in addition and a portion of the gate line where the thin film transistor is formed is formed wider than the remaining portion of the gate line. [0028] Preferably, the semiconductor layer is formed over the gate line where a thin film transistor will be formed as well as on the gate insulating layer where the data line is formed. [0029] Preferably, a source electrode of a thin film transistor does not protrude from the data line . [0030] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS [0031] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: [0032] [0032]FIG. 1 illustrates a layout of a thin film transistor in a general liquid crystal display; [0033] [0033]FIG. 2 illustrates a layout of a thin film transistor in a liquid crystal display according to a first embodiment of the present invention; [0034] [0034]FIG. 3 illustrates a cross-sectional view of a thin film transistor in a liquid crystal display according to a first embodiment of the present invention along a cutting line I-I′ in FIG. 2; [0035] [0035]FIG. 4 illustrates a layout of a thin film transistor in a liquid crystal display according to a second embodiment of the present invention; and [0036] [0036]FIG. 5 illustrates a cross-sectional view of a thin film transistor in a liquid crystal display according to a second embodiment of the present invention along a cutting line II-II′ in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION [0037] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. [0038] [0038]FIG. 2 illustrates a layout of a thin film transistor in a liquid crystal display according to a first embodiment of the present invention and FIG. 3 illustrates a cross-sectional view of a thin film transistor in a liquid crystal display according to a first embodiment of the present invention along a cutting line I-I′ in FIG. 2. Moreover, FIG. 4 illustrates a layout of a thin film transistor in a liquid crystal display according to a second embodiment of the present invention and FIG. 5 illustrates a cross-sectional view of a thin film transistor in a liquid crystal display according to a second embodiment of the present invention along a cutting line II-II′ in FIG. 4. [0039] Referring to FIG. 2 and FIG. 3, a thin film transistor in a liquid crystal display according to a first embodiment of the present invention has a gate line 1 formed in one direction on a glass substrate 10 . The gate lines are separated by predetermined intervals from another one. A gate insulating layer 5 is formed on an entire surface of the substrate including the gate line 1 , and a semiconductor layer 3 as an active layer of the thin film transistor is formed like an island on the gate insulating layer 5 over a predetermined area (an area where the thin film transistor will be formed) of the gate line 1 . [0040] A data line 2 is formed on the gate insulating layer 5 in a direction perpendicular to the gate line 1 so as to be overlapped with one side portion of the semiconductor layer 3 toward a direction of the gate line 1 . And, a drain electrode 2 b is formed across the other side portion of the semiconductor layer 3 confronting the data line 2 and the gate insulating layer 5 . [0041] A passivation layer 6 having a contact hole for the drain electrode 2 b is formed on an entire surface of the substrate 10 including the data line 2 and drain electrode 2 b . And, a pixel electrode 4 is formed in the pixel area so as to be electrically connected to the drain electrode 2 b through the contact hole. [0042] As it can be seen from FIG. 2, the thin film transistor in the liquid crystal display according to the present invention has a source electrode that does not extend from the data line 2 and a gate electrode that does not extend from the gate line 1 . However, while the area used to form the electrodes and transistor is substantially reduced, a portion of the gate line 1 on the area where the thin film transistor will be formed becomes wider than the rest portion of the gate line 1 . This is to say that the opening ratio may be further increased by judicious design. [0043] Referring to FIG. 4 and FIG. 5, a thin film transistor in a liquid crystal display according to a second embodiment of the present invention has a gate line 1 formed in one direction on a glass substrate 10 (with predetermined intervals separating gate lines). A gate insulating layer 5 is formed on an entire surface of the substrate including the gate line 1 , and a semiconductor layer 3 is formed over a predetermined area(the area where the thin film transistor will be formed) of the gate line 1 and on the gate insulating layer 5 where a data line will be formed. However, unlike the previous embodiment, in the embodiment shown in FIGS. 4 and 5, the semiconductor layer 3 is formed perpendicular to the gate line 1 and only a portion extends parallel to the gate line 1 . [0044] A data line 2 is formed on the semiconductor layer 3 in a direction perpendicular to the gate line 1 . And, a drain electrode 2 b is formed across the other side portion of the semiconductor layer 3 confronting the data line 2 and the gate insulating layer 5 . [0045] A passivation layer 6 having a contact hole on the drain electrode 2 b is formed on an entire surface of the substrate 10 including the data line 2 and drain electrode 2 b . And, a pixel electrode 4 is formed in the pixel area so as to be electrically connected to the drain electrode 2 b through the contact hole. [0046] As it can be seen from FIG. 4, the data line 2 is formed wider than the semiconductor layer 3 . And, the thin film transistor in the liquid crystal display according to the present invention has a source electrode that does not extend from the data line 2 and a gate electrode that does not extend from the gate line 1 . In this embodiment however, while the opening ratio is increased, a portion of the gate line 1 on the area where the thin film transistor will be formed becomes wider than the remaining portion of the gate line 1 . Besides, the semiconductor layer 3 formed under the data line 2 is built in one body with the semiconductor layer 3 formed at the area where the thin film transistor will be formed. [0047] A method of fabricating the above-constituted thin film transistor in a liquid crystal display according to the present invention is explained as follows. [0048] First of all, a metal or conductive semiconductor layer is deposited on a substrate 10 , and then removed selectively so as to form a gate line 1 . In this case, the gates and electrodes does not protrude from the gate line 1 corresponding to an area where a thin film transistor will be formed while the gate line 1 is formed to have a portion wider than the remain portion of the gate line 1 . [0049] A gate insulating layer 5 is deposited on an entire surface of the substrate 10 having the gate line 1 formed thereon, and a semiconductor layer 3 is deposited on the gate insulating layer 5 , and then the semiconductor layer 3 is selectively removed so as to form an active area of the thin film transistor. In this case, the first embodiment of the present invention removes the semiconductor layer 3 such that only an island-like portion of the semiconductor layer 3 remains over the gate line 1 on the area where the thin film transistor will be formed. And, the second embodiment of the present invention removes the semiconductor layer 3 such that a portion of the semiconductor layer 3 remains over the gate line 1 on the area where the thin film transistor will be formed as well as on the gate insulating layer 5 of the portion where the data line 2 will be formed. [0050] A metal layer is deposited on an entire surface of the substrate, and then patterned to form a data line 2 and a drain electrode 2 b . In this case, the data line 2 has no protruding source electrode and is formed to be wider than the semiconductor layer 3 . And, the drain electrode 2 b is not formed in the pixel area but over the gate line 1 . [0051] Subsequently, a passivation layer 6 is deposited on an entire surface of the substrate. A contact hole is then formed in the passivation layer 6 . A transparent electrode(ITO) is deposited on an entire surface so as to be connected to the drain electrode 2 b through the contact hole, and then patterned to remain in the pixel area only so as to form a pixel electrode 4 . [0052] Accordingly, the liquid crystal display and fabricating method thereof according to the present invention have the following advantages or effects as follows. [0053] First, the thin film transistor is not formed in the pixel area but on the gate line at the intersection between the gate and data lines, thereby maximizing the opening ratio of the liquid crystal display. [0054] Second, the gate and source electrodes do not protrude from the gate and data lines, respectively, thereby eliminating the fluctuations of the parasitic capacitances between the gate and source electrodes and between the gate and drain electrodes of the thin film transistor. Therefore, the present invention decreases flickering of the display. [0055] It will be apparent to those skilled in the art than various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Disclosed are a liquid crystal display and a fabricating method thereof enabling to improve an opening ratio of the liquid crystal display by modifying a structure of a thin film transistor. Each pixel of the liquid crystal display includes a gate line formed on a substrate in one direction with a predetermined interval from another one, a data line formed in a direction perpendicular to the gate line so as to define a pixel area, a thin film transistor formed on the gate line at an intersection between the gate and data lines, and a pixel electrode formed in the pixel area.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an ink jet recording apparatus in which ink is caused to fly by the utilization of pressure, preferably heat energy, to thereby effect recording on a recording medium. 2. Related Background Art An ink jet recording apparatus is provided with a construction in which ink is supplied to a recording head and energy generating means is driven on the basis of recording information, whereby the ink is discharged from ink discharge ports to thereby form flying ink droplets and the ink droplets are caused to adhere to a recording medium disposed in opposed relationship with the recording head to thereby accomplish recording. In the recording apparatus of this kind, as shown in FIG. 6 of the accompanying drawings, ink 12 or foreign substances including dust may sometimes adhere to the discharge port forming surface of the recording head including the discharge port portion. In order to remove such ink and foreign substances, there is often provided a cleaning member such as a cleaning blade for cleaning the discharge port forming surface. Now, as the cleaning member of the prior-art ink jet recording apparatus, there has been proposed one which, as shown, for example, in Japanese Laid-Open Patent Application No. 61-230947, is designed to be put in and out to remove ink adhering to the discharge port forming surface of the recording head after the use of a recovery pump, or one, which, as shown in Japanese Laid-Open Utility Model Application No. 58-128034, is designed to contact with a recording head returned to a home position set in a non-recording area, always with a predetermined amount of contact, a predetermined thickness, predetermined dimensions and a predetermined number of cleaning blades. Also, as shown in Japanese Laid-Open Patent Application No. 58-94472, there has been proposed one in which a blade is disposed within the deceleration section of a carriage when a recording head carried on the carriage is returned to the non-recording area side, and cleaning is effected in the decelerated condition of the carriage. Further, as shown in Japanese Laid-Open Patent Application No. 59-14964, there has been proposed one in which a cleaning blade provided on an endless belt disposed in opposed relationship with the discharge port forming surface of a recording head is rotated from up to down to thereby effect cleaning. In these examples of the prior art, however, the possible cleaning condition for the discharge port forming surface of the recording head is always made simply constant irrespective of the recording condition or irrespective of the difference in recording mode and therefore, there have been cases where the cleaning condition is good in the early stage of cleaning, but when the recording condition or the recording mode changes, sufficient cleaning cannot be accomplished depending on the recording mode, that is, unsatisfactory cleaning begins to take place intermittently and finally, after a long-time use, unsatisfactory cleaning takes place in every recording mode. Accordingly, the stable obtainment of a long-period cleaning effect has heretofore not been achieved sufficiently. In view of the above-noted problem, we have made one study after another and have made the following matter clear. Usually in cleaning, one kind of cleaning condition is set. In this case, the set condition for cleaning is suited for particular one of a plurality of recording modes and therefore, a good result has been obtained in the process wherein this particular recording mode is continued. In the other recording mode, however, unsatisfactory cleaning has gradually begun to take place and when the other recording mode and said particular mode have been repetitively carried out, unsatisfactory cleaning has gradually begun to take place even in the particular mode wherein good cleaning was seen at the beginning, and the result has been a case where in the two modes, there takes place unsatisfactory cleaning as shown in FIG. 4 of the accompanying drawings. Further examinations on the basis of the above findings revealing the following: i) When the recording mode is changed, for example, the scanning speed of a carriage carrying a recording head thereon is changed as in the so-called NLQ (near letter quality) recording wherein recording is effected at a low speed to thereby obtain records of high quality and the so-called draft recording wherein recording is effected at a high speed, the state of contact of the cleaning member with the discharge port forming surface of the recording head differs and gives rise to various influences. That is, the cleaning member mounted on the apparatus side is installed in a predetermined condition and therefore, when the speed of movement of the carriage is high as in the draft recording, the shock during the contact of the cleaning member with the discharge port forming surface is strong and the influence of the contact may result in the retraction of the meniscus position formed in the discharge ports, which in turn may result in unsatisfactory discharge attributable to the entry of bubbles and the retraction of the meniscus. Or when the speed of movement of the carriage is low as during the NLQ recording, the state of contact of the cleaning member with the discharge port forming surface becomes weak and ink or foreign substances adhering to the discharge port forming surface cannot be sufficiently removed and a pool of ink may be created by incomplete wiping, and this may cause unsatisfactory discharge. That is, where a predetermined cleaning condition is set, the apparent state of contact of the cleaning member with the discharge port forming surface (the cleaning condition) differs by the recording speed condition being changed. That is, it is preferable in effecting good cleaning of the discharge port forming surface to adopt a construction in which as the speed of the carriage becomes higher as in the aforedescribed draft recording, the amount of contact of the wiper with the discharge port forming surface is made smaller and as the speed of the carriage becomes lower as in the aforedescribed NLQ recording, the amount of contact of the wiper with the discharge port forming surface is made greater to thereby make the apparent state of contact constant. ii) The amount of ink adhering to the discharge port forming surface is varied by a variation in the recording density, i.e., a variation in the number of discharge ports which discharge the recording liquid per unit time, whereby the state of contact of the cleaning member with the discharge port forming surface of the recording head becomes different and this gives rise to various influences. That is, the cleaning member mounted on the apparatus side is installed in a predetermined condition as previously described and therefore, for example, when high density recording is effected, the amount of ink adhering to the discharge port forming surface becomes greater. When the cleaning of the discharge port forming surface to which a great amount of ink droplet has adhered is effected by the cleaning member, the contact of the cleaning member with the discharge port forming surface cannot be sufficiently be accomplished due to the surface tension of the adhering ink and the amount of adhering ink, and this may sometimes result in the deterioration of the state of contact, and removal of the ink and foreign substances cannot be accomplished sufficiently and a pool of ink is created by incomplete wiping, and this may cause unsatisfactory discharge. Or when low density recording is effected, not so much ink adheres to the discharge port forming surface and therefore, the shock during the contact of the cleaning member with the discharge port forming surface is strong and this may result in the retraction of the meniscus, which may cause unsatisfactory discharge attributable to the entry of bubbles and the retraction of the meniscus. That is, when a predetermined cleaning condition is set, the apparent state of contact of the cleaning member with the discharge port forming surface (the cleaning condition) becomes different by the recording density condition being changed. That is, it is preferable in effecting good cleaning of the discharge opening forming surface to adopt a construction in which as the recording density becomes lower, the amount of contact of the cleaning blade with the discharge port forming surface is made smaller and as the recording density becomes higher, the amount of contact of the cleaning blade with the discharge port forming surface is made greater to thereby make the apparent state of contact constant. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-noted problems peculiar to the prior art and to provide an ink jet recording apparatus of high reliability in which even where there is a plurality of recording modes in which the speed of a carriage is varied or the recording density is varied, the state of contact of a cleaning blade with a discharge port forming surface is made constant to thereby accomplish good cleaning and unsatisfactory discharge of ink does not occur after the completion of the cleaning. Particularly in an ink jet recording apparatus directed to high-speed recording, there has been adopted a cleaning condition similar to that in a case where only when cleaning is effected, the speed of a carriage is reduced (decelerated cleaning) to effect low-speed recording, but to achieve still higher speed recording (to increase the throughput), decelerated cleaning cannot cope therewith. The present invention makes high-speed recording possible without reducing the throughput and makes good cleaning of the discharge port forming surface of a recording head possible. It is also an object of the present invention to provide an ink jet recording apparatus having: an ink jet head provided with a discharge port forming surface formed with discharge ports for discharging ink therethrough; a cleaning member for bearing against the discharge port forming surface of said ink jet head to clean said discharge port forming surface; recording mode setting means capable of setting a first recording mode in which the ink is discharged from said ink jet head to effect recording, and a second recording mode differing from said first recording mode; cleaning mode setting means capable of setting a first cleaning mode corresponding to said first recording mode set by said recording mode setting means, and a second cleaning mode corresponding to said second recording mode set by said recording mode setting means; and driving means for moving said ink jet head and said cleaning member relative to each other to effect the cleaning of said discharge port forming surface. It is a further object of the present invention to provide an ink jet recording apparatus having: an ink jet head provided with discharge ports for discharging ink therethrough; carriage means for moving said ink jet head between a recording position in which recording is effected with said ink jet head opposed to a recording medium and a non-recording position in which said ink jet head is retracted from said recording position; a cleaning member provided in the movement path between said recording position and said nonrecording position and adapted to bear against a discharge port forming surface in which said discharge ports of said ink jet head are formed and effecting the cleaning of said discharge port forming surface; recording mode setting means capable of setting a first recording mode in which ink is discharged from said ink jet head to effect recording, and a second recording mode differing from said first recording mode; and cleaning mode setting means capable of setting a first cleaning mode corresponding to said first recording mode set by said recording mode setting means, and a second cleaning mode corresponding to said second recording mode set by said recording mode setting means. The first recording mode and the second recording mode differing from the first recording mode, herein referred to, are typified by one of the high-speed recording mode, the low speed recording mode, the monochromatic recording mode, the polychromatic recording mode, the high-density recording mode and the low-density recording mode or a complex mode of these. The aforedescribed high-speed recording mode is called the draft recording, and the low-speed recording mode is directed to recording of high quality and is called NLQ (near letter quality) or LQ. The recording speed is such that when the speed of the low-speed recording is 1, the speed of the high-speed recording is about double that of the low-speed recording Also, the aforedescribed low-density recording includes alphanumeric characters used in ordinary letter sentences, and refers to the recording in which when for example, a font box for one character is a matrix of 48×36 (length×width) dots, about 20-30% of the matrix is filled up, and the high-density recording refers to the recording in which the threshold value of the low density is exceeded. Particularly in the present invention, it is to be understood that distinction is made between the high-density recording and the low-density recording with the average duty when predetermined continuous recording is effected as the subject, and for example, even a case where there is one character of full matrix pattern in a usually used letter sentence is judged as the low-density recording in accordance with the definition in the aforedescribed example. Also, the first cleaning condition and the second cleaning condition are relative, and differ by varying the number of cleaning members bearing against the discharge port forming surface to effect cleaning, varying the area of contact by the cleaning member, selectively using cleaning members of different materials, changing the amount of overlap or entry (the relative position) of the cleaning member into the recording head position including the area of passage of the recording head, changing the condition of the cleaning member so that the cleaning action time may become constant even when the speed of movement of the recording head varies, changing the cleaning time itself, relatively changing the cleaning direction (only one of the horizontal direction and the vertical direction, or the forward direction and the backward direction), or relatively changing the angle of installation of the cleaning member disposed relative to the discharge port forming surface, or by a combination of the above. In the present invention, even when the recording mode is changed, a cleaning condition fit for each recording mode can be appropriately given to properly accomplish the cleaning by the cleaning member and therefore, the deterioration of the quality of recording by unsatisfactory discharge can be broadly prevented, and even immediately after the change to a different recording mode, more stable cleaning can be accomplished by a cleaning condition corresponding to the changed recording mode, whereby stable recording can be maintained. In the above-described construction, it is preferable that the number, dimensions and material of the cleaning members and the amount of contact of the cleaning members with the recording head be varied by the speed of the carriage. Also, in the above-described construction, it is preferable that the number, dimensions and material of the cleaning members and the amount of contact of the cleaning members with the recording head be varied by the recording density. When carrying out the ink jet recording apparatus of the present invention, the cleaning condition such as one of the amount of contact, number, dimensions and material of the cleaning blades optimally given in each recording mode or a combination thereof is controlled on the basis of a signal which has detected a variation in the speed of the carriage or a variation in the recording density, or in conformity with the set recording mode, and for example, where the speed of the carriage is low or the recording density is high when the speed of the carriage or the recording density has varied, the amount of contact (the amount of entry) of the cleaning blade with (into) the discharge port forming surface of the recording head is controlled in the longer direction and where the speed of the carriage is high or the recording density is low, the amount of contact of the cleaning blade is controlled in the shorter direction. Also, the control of the cleaning condition permits various combinations within a range which satisfies the aforedescribed conditions. Thus, over a predetermined area of the ink discharge port forming surfaces matching each recording mode, a cleaning (wiping) operation which ensures good contact of the blade with the discharge port forming surface and which is moreover high in efficiency can be accomplished. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing the essential portions of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing the essential portions of an ink jet recording apparatus according to another embodiment of the present invention. FIG. 3 is a schematic perspective view showing the essential portions of an ink jet recording apparatus according to still another embodiment of the present invention. FIG. 4 is a schematic view showing the state of unsatisfactory cleaning of a discharge port forming surface. FIG. 5 is a schematic view showing a well cleaned discharge port forming surface. FIG. 6 is a schematic view showing a discharge port forming surface to which ink and dust adhere. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will hereinafter be described specifically with reference to the drawings. Embodiment 1 Description will first be made of an embodiment in which the amount of contact of a cleaning blade with a recording head is changed. FIG. 1 is a schematic perspective view showing the essential portions of an ink jet recording apparatus according to an embodiment of the present invention. In FIG. 1, the reference number 1 designates a cleaning blade which is a cleaning member, the reference numeral 2 denotes a cleaning blade supporting member for supporting the cleaning blade 1, the reference numeral 3 designates a contact amount adjusting hole for adjusting the longitudinal position of the cleaning blade 1 and adjusting the amount of contact of the cleaning blade with the discharge port forming surface of a recording head, and the reference numeral 4 denotes a stopper for controlling the retracted position of the cleaning blade 1 relative to the supporting member 2. The stopper 4 is provided, for example, on the side wall of a capping member, not shown, for recovering and holding the recording head. The reference numeral 5 designates springs for biasing the cleaning blade 1 in the backward direction in which the cleaning blade is spaced apart from the recording head, the reference numeral 6 denotes a solenoid for driving the cleaning blade 1 forwardly toward the recording head, the reference numeral 7 designates the recording head, the reference numeral 8 denotes a discharge port forming surface which is in the front of the recording head and in which ink discharge ports are arranged, the reference numeral 9 designates guide shafts installed on the frame member of the recording apparatus, and the reference numeral 10 denotes a carriage carrying the recording head 7 thereon and movable in the direction of recording column along the guide shafts 9. This carriage 10 is scanned by the drive of a drive source, not shown. Where the recording apparatus has two carriage speeds in conformity with the quality of recording, on the low speed side, the cleaning blade 1 is pushed out by the pushing-out operation of the solenoid 6 and the amount of contact of the cleaning blade 1 with the discharge port forming surface 8 during wiping becomes greater. On the other hand, when the carriage speed has shifted to the high speed side, the pushing-out operation of the solenoid 6 is released and the cleaning blade 1 is retracted by the spring forces of the springs 5. That is, the cleaning blade 1 is moved away from the recording head 7 until the stopper 4 thereof strikes against the rear wall of the contact amount adjusting hole 3 in the cleaning blade supporting member 2. By this retracting movement, the amount of contact of the cleaning blade 1 with the discharge port forming surface 8 becomes smaller when the carriage speed is on the high speed side. The amount of contact in a case where the carriage speed (the recording speed) has two modes of low speed and high speed differs depending on the carriage speed, but it is preferable that the amount of contact be selected from a range of 0.8-2 mm at the low speed and be selected from a range of 0.15-1.2 mm at the high speed. This amount of contact refers to the amount of overlap between the cleaning blade 1 and the discharge port forming surface of the recording head 7 which is indicated by l in FIG. 1. Now, in the cleaning of the discharge port forming surface by the cleaning blade, the following conditions are required as premises. (1) That during the cleaning (during the contact of the cleaning blade with the discharge port forming surface), the edge portion of the cleaning blade contacts the discharge port forming surface. This is because when the cleaning blade is in contact with the discharge port forming surface and is moved, ink droplets and dust or the like adhering to the discharge port forming surface are scraped off substantially by the edge portion of the cleaning blade. Thus, in a state in which the amount of contact of the cleaning blade is too great and the cleaning blade is bent horizontally during its contact, there is no effect of cleaning, and this may result in a state in which the ink and dust are collected near the discharge ports, which in turn may result in unsatisfactory discharge. (2) That during cleaning, the cleaning blade does not vibrate or bound on the discharge port forming surface. If the cleaning blade bounds on the discharge port forming surface, there will not be obtained the effect of uniformly wiping the discharge port forming surface and also, the retraction of the meniscus in the discharge ports will be caused by the shock or the like when the cleaning blade bounds, and bubbles may enter the discharge ports, thus resulting in unsatisfactory discharge. (3) That the scattering of the ink from the cleaning blade when the cleaning blade separates from the discharge port forming surface immediately after cleaned is minimum. By cleaning, ink droplets and dust adhering to the cleaning blade side may sometimes be scattered due to the vibration of the blade when the blade separates from the discharge port forming surface. Such scattered ink may sometimes contaminate the interior of the apparatus of the recording medium and therefore, it is preferable that a material having a certain degree of rigidity and yet having flexibility by used as the material of the cleaning blade. The cleaning blade suitably used in the present embodiment may preferably have a hardness greater than 35° and less than 80° (Japanese Industrial Standard (JIS), which is equivalent to greater than 36° and less than 83° Shore-Durometer A hardness), a thickness greater than 0.2 mm and less than 1.5 mm and a free length ranging from 2 mm to 15 mm, whereby the aforementioned premises required of the cleaning blade can be satisfied. Embodiment 2 When the recording density is on the low density side, the cleaning blade 1 is moved in the same direction as that when the carriage speed is on the high speed side, i.e., the direction in which the amount of contact of the cleaning blade with the discharge port forming surface 8 becomes smaller, and when the recording density is on the high density side, the cleaning blade 1 is moved in the same direction as that when the carriage speed is on the low speed side i.e., the direction in which the amount of contact of the cleaning blade with the discharge port forming surface 8 becomes greater. According to Embodiments 1 and 2 described above, the cleaning blade 1 which is a cleaning member for removing (wiping off) ink or foreign substances adhering to the discharge port forming surface 8 of the recording head 7 is movable back and forth and the longitudinal position thereof is adjusted in conformity with a variation in the carriage speed or the recording density, whereby the amount of contact of the cleaning blade 1 with the discharge port forming surface 8 of the recording head 7 may be adjusted and therefore, there is provided an ink jet recording apparatus in which even if the carriage speed or the recording density varies as shown in FIG. 5, no ink or dust remains on the discharge port forming surface after cleaning and the occurrence of unsatisfactory discharge can be prevented and moreover a high cleaning performance can be secured for a long period of time without being affected by the recording condition. Embodiment 3 Description will now be made of an embodiment which uses a plurality of kinds of cleaning blades differing in condition from each other. FIG. 2 is a schematic perspective view showing the essential portions of an ink jet recording apparatus according to another embodiment of the present invention. In the present embodiment, use is made of a plurality of (in the shown embodiment, two) cleaning blades 1a and 1b differing from each other in the amount of contact with the discharge port forming surface 8 of the recording head 7 and the blade thickness. The cleaning blades 1a and 1b are supported for movement back and forth by respective support members 2a and 2b, and are designed to have their longitudinal positions independently controlled by individual solenoids 6a and 6b. Accordingly, the plurality of cleaning blades 1a and 1b differing in the amount of contact during cleaning and differing in blade thickness can be selectively put in and out in conformity with a variation in the carriage speed or the recording density. Control is effected so that for example, when the carriage speed is on the high speed side or when the recording density is on the low density side, use is made of the cleaning blade 1b having a great blade thickness, e.g. greater than 0.5 mm and less than 1.5 mm and having a small amount of contact, and that when the carriage speed is on the low speed side or when the recording density is on the high density side, use is made of the cleaning blade 1a having a small blade thickness, e.g. greater than 0.2 mm and less than 0.8 mm and having a great amount of contact. The embodiment of FIG. 2 differs in the above-described point from the embodiment of FIG. 1, but is of the same construction in the other points, and corresponding portions thereof are designated by identical reference numerals and need not be described in detail. Again by the embodiment of FIG. 2, the amounts of contact of the cleaning blades 1a and 1b with the discharge port forming surface of the recording head 7 and the blade thicknesses can be adjusted in conformity with any variation in the carriage speed or the recording density and accordingly, as in the aforedescribed case, no ink and dust remains on the discharge port forming surface as shown in FIG. 5 after the cleaning operation (the wiping-off) by the cleaning blades 1a and 1b and unsatisfactory discharge can be eliminated. Embodiment 4 Description will now be made of an embodiment which uses cleaning blades formed of two different materials. For example, a silicone material of high hardness relatively lacks tackiness and has good sharpness when it is worked into a blade, and permits the edge of the blade to be suitably formed. Accordingly, this material exhibits a good cleaning effect even for high-speed carriage movement by high-speed recording or for high-density recording. Also, nitrile butadiene rubber of low hardness containing hydrogen therein is relatively flexible and tacky, but permits the edge of the blade to be formed well when it is worked into a blade. Accordingly, this material exhibits a good cleaning effect for low-speed carriage movement by low-speed recording or for low-density recording without injuring the discharge port forming surface. When actually the apparatus construction as shown in FIG. 2 was utilized and silicone having a hardness of 50° (JIS), which is equivalent to 52° Shore-Dorometer A hardness, an amount of entry 0.5 mm and a free length of 0.8 mm was used as a high-speed blade and nitrile or butadiene rubber containing hydrogen hydrogenated nitrile butadiene rubber and having a hardness of 35° (JIS), which is equivalent to hardness, 36° Shore-Durometer A, an amount of entry 1.0 mm and a free length of 0.5 mm was used as a low-speed blade, there could be obtained a very good cleaning effect as shown in FIG. 5 under each recording condition. Embodiment 5 Description will further be made of an embodiment in which the angle of mounting of the cleaning blade relative to the recording head is changed to thereby change the amount of contact and the manner in which the edge of eh blade is positioned. The present embodiment, as shown in FIG. 3, is of a construction in which the angle of contact of the cleaning blade 1 with the recording head 7 is adjusted about a rotary shaft 11 provided in the central portion of the blade supporting member 2, by driving a solenoid 6. In this construction, when low-speed recording or high-density recording is effected, the solenoid is driven so that the blade 1 may bear against the recording head at an angle approximate as much as possible to a right angle, e.g. θ=0°-30°, thereby enhancing the contact pressure. On the other hand, when high-speed recording or low-density recording is effected, the blade 1 is set to an angle side on which it lies down, and the contact pressure is reduced, e.g. to θ=25°-45°, thereby adjusting the contact condition. By doing so, the contact pressure can be made optimum one conforming to the recording conditions, and the cleaning effect is improved as shown in FIG. 5. These angles are not limited to this range, but may suitably be selected within a range for which the cleaning characteristic is improved, particularly a range of θ=0°-45°. In the above-described embodiments description has been made with respect to a case where the amount of contact of the cleaning member with the discharge port forming surface 8 of the recording head 7 and the blade thickness are varied in conformity with any variation in the carriage speed or the recording density, or a case where blades of different materials are used or the angle of contact of the blade with the discharge port forming surface is varied, but when carrying out the present invention, the dimensions and materials of the cleaning members 1 may be made variable and adjusted, such as using the same kind of rubber for the cleaning members and changing the hardness of the rubber, and changing the degree of surfaces smoothness of the cleaning members, whereby a similar effect can also be achieved. The present invention brings about an excellent effect particularly in a recording head and recording apparatus of the bubble jet type, among the ink jet recording systems. As regards the typical construction and principle thereof, a system using the basic principle disclosed, for example, in U.S. Pat No. 4,723,129 or U.S. Pat. No. 4,740,796 is preferable. This system is applicable to both of the so-called on-demand type and the so-called continuous type, and particularly in the case of the on-demand type, it is effective because at least one driving signal corresponding to recording information and providing a rapid temperature rise exceeding nuclear boiling is applied to an electro-thermal converting member disposed correspondingly to a sheet or a liquid path retaining ink therein, thereby generating heat energy in the electro-thermal converting member, and film boiling is caused to occur in the heat-acting surface of a recording head with a result that a bubble in liquid (ink) corresponding at one to one to said driving signal can be formed. By the growth and contraction of this bubble, the liquid (ink) is discharged through a discharge opening to thereby form at least one droplet. If said driving signal is made into the form of a pulse, the growth and contraction of the bubble take place appropriately on the spot and therefore, discharge of the liquid (ink) which is particularly excellent in responsiveness can be accomplished, and this is more preferable. The signal as described in U.S. Pat. No. 4,463,359 and U.S. Pat. No. 4,345,262 is suitable as this pulse-shaped driving signal. If the conditions described in U.S. Pat. No. 4,313,124 which discloses an invention relating to the temperature rise rate of said heat-acting surface are adopted, more excellent recording can be accomplished. As the construction of the recording head, besides a construction comprising a combination of a discharge port, a liquid path and an electro-thermal converting member as disclosed in each of the above-mentioned patents (a rectilinear liquid flow path or a perpendicular liquid flow path), a construction using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600 which discloses a construction in which a heat-acting portion is disposed in a bent area is also covered by the present invention. In addition, the present invention is also effective if it adopts a construction based on Japanese Laid-Open Patent Application No. 59-123670 which discloses a construction in which a slit common to a plurality of electrothermal converting members is used as the discharge portion of the electro-thermal converting members or Japanese Laid-Open Patent Application No. 59-138461 which discloses a construction in which an opening for absorbing the pressure wave of heat energy corresponds to the discharge portion. Further, as a recording head of the full line type having a length corresponding to the width of the largest recording medium on which the recording apparatus can effect recording, use may be made of any of a construction which satisfies that length by a combination of a plurality of recording heads as disclosed in the above-mentioned publications and a construction as a single recording head formed as a unit, and the present invention can display the above-described effect more effectively. In addition, the present invention is also effective in a case where use is made of a recording head of the interchangeable chip type which permits the electrical connection to the apparatus body and the supply of ink from the apparatus body by being mounted on the apparatus body, or a recording head of the cartridge type integrally provided on the recording head itself. Also, the addition of recovery means, preliminary auxiliary means, etc. for the recording head which are provided in the construction of the recording apparatus of the present invention can more stabilize the effect of the present invention and therefore, this is preferable. Specifically, they include capping means and pressing or suction means for the recording head, and preheating means comprising an electro-thermal converting member or a heating element discrete therefrom or a combination of these, and it is also effective for accomplishing stable recording to carry out the preliminary discharge mode in which discharge discrete from recording is effected. Further, as regards the recording modes of the recording apparatus, use may be made not only of the recording mode of only the main color such as black, but also of a recording head constructed as a unit or comprising a combination of a plurality of heads, and the present invention is also very effective for an apparatus provided with at least one of a complex color comprising different colors and full color comprising a mixture of colors. In the above-described embodiments of the present invention, ink has been described as liquid, but use may be made of any ink which solidifies at room temperature or below and softens or liquifies at room temperature, or any ink which assumes its liquid phase when a recording signal is imparted thereto, because in the above-described ink jet, it is popular to control the temperature so that ink itself is temperature-regulated within a range of 30° C. to 70° C. and the viscosity of the ink is within a stable discharge range. In addition, the temperature rise by heat energy is positively used as the energy for the phase change of ink from its solid state to its liquid state to thereby prevent the solidification of the ink, or use is made of ink which solidified when it is left for the purpose of preventing the evaporation of the ink, and in any case, the use of ink of such a nature that it is liquefied only by heat energy, such as ink which is liquefied by heat energy being imparted thereto in conformity with a recording signal and is discharged in the form of ink liquid or ink which begins to solidify at point of time whereat it arrives at the recording medium is also applicable to the present invention. The present invention is also effectively used for the cleaning when such ink adheres to the discharge port forming surface and is thereby solidified. In such a case, the ink may be in a form as described in Japanese Laid-Open Patent Application No. 54-56847 or Japanese Laid-Open Patent Application No. 60-71260 wherein the ink is opposed to an electro-thermal converting member while being retained as a liquid or a solid in the recesses of a porous sheet or a through-hole. In the present invention, what is most effective for the above-described inks is one which executes the above-described film boiling system. As is apparent from the foregoing description, in an ink jet recording apparatus having cleaning members for contacting with the discharge port forming surface of a recording head to thereby remove ink or foreign substances adhering to said discharge port forming surface, the number, dimensions and materials of the cleaning members and the amount of contact of the cleaning members with the recording head are made variable and these conditions can be varied in conformity with any variation in the carriage speed or the recording density and therefore, the cleaning condition can be made constant in conformity with the recording condition and the wiping of the discharge port forming surface of the recording head by the cleaning member can be accomplished effectively, and thus, cleaning characteristic for a long period of time is improved and it has become possible to effect good recording without the occurrence of unsatisfactory discharge. As is apparent from the foregoing description, according to the present invention, the problem which has arisen when the same cleaning condition is adopted even for a change in a plurality of recording modes as in the prior art can be solved, and the cleaning condition suitable for each recording mode can be provided and therefore, the cleaning condition in that recording mode itself can be adjusted optimally and thus, the occurrence of unsatisfactory discharge can be broadly prevented, and even immediately after the change to a different recording mode, more stable recording can be maintained by a cleaning condition suitable for the changed recording mode while the cleaning load in the changed recording mode is reduced. Particularly, the present invention when effecting high-speed recording, can set a cleaning condition suitable for high-speed recording and therefore, can accomplish good cleaning without reducing, as in the prior art, the throughput, which is reduced when decelerated cleaning is effected.

An ink jet recording apparatus has an ink jet head provided with a discharge port forming surface formed with discharge ports for discharging ink therethrough, a cleaning member for bearing against the discharge port forming surface of the ink jet head to clean the discharge port forming surface, a recording mode setter capable of setting a first recording mode in which the ink is discharged from the ink jet head to effect recording, and a second recording mode differing from the first recording mode, a cleaning mode setter means capable of setting a first cleaning mode corresponding to the first recording mode set by the recording mode setter, and a second cleaning mode corresponding to the second recording mode set by the recording mode setter, and a driver means for moving the ink jet head and the cleaning member relative to each other to effect the cleaning of the discharge port forming surface.

RELATED APPLICATIONS This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 61/420,538 filed on Dec. 7, 2011 pursuant to 35 U.S.C.§119(e). The entire content of this application is hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device. 2. Description of the Related Art The degree of integration of semiconductor integrated circuits, namely, integrated circuits using metal oxide semiconductor (MOS) transistors, has been increasing. The increasing degree of integration of such integrated circuits results in MOS transistors having small sizes reaching nano-scale dimensions. Inverter circuits are fundamental circuits of digital circuits, and the increasing decrease in the size of MOS transistors included in inverter circuits causes difficulty in suppressing leak currents, leading to problems of reduced reliability due to hot carrier effects and of the reduction in the area of the circuits being prevented because of the requirements of the secure retention of necessary currents. To overcome the above problems, a surrounding gate transistor (SGT) having a structure in which a source, gate, and drain are arranged vertically with respect to a substrate and in which the gate surrounds an island-shaped semiconductor layer has been proposed (for example, Japanese Unexamined Patent Application Publications No. 2-71556, No. 2-188966, and No. 3-145761). It is known that in a static memory cell, the current driving force of a driver transistor is made double the current driving force of an access transistor to ensure operational stability (H. Kawasaki, M. Khater, M. Guillorn, N. Fuller, J. Chang, S. Kanakasabapathy, L. Chang, R. Muralidhar, K. Babich, Q. Yang, J. Ott, D. Klaus, E. Kratschmer, E. Sikorski, R. Miller, R. Viswanathan, Y. Zhang, J. Silverman, Q. Ouyang, A. Yagishita, M. Takayanagi, W. Haensch, and K. Ishimaru, “Demonstration of Highly Scaled FinFET SRA M Cells with High-κ/Metal Gate and Investigation of Characteristic Variability for the 32 nm node and beyond”, IEDM, pp. 237-240, 2008). To construct a static memory cell using the above SGT, two driver transistors are used because of the need for a double gate width in order to make it feasible to make the current driving force of a driver transistor double the current driving force of an access transistor to ensure operational stability. This leads to an increase in memory cell area. Further, an SGT production method has been proposed of forming a pillar-shaped semiconductor layer, depositing a gate conductive film on the pillar-shaped semiconductor layer, performing planarization, and then etching back the gate conductive film to obtain a desired length (Japanese Unexamined Patent Application Publication No. 2009-182317). This high-degree-of-integration, high-performance, and high-yield SGT production method allows the physical gate length of the SGT to be kept uniform over all the transistors on a wafer. Additionally, the increasing decrease in the size of static memory cells reduces the gate capacitance or diffusion layer capacitance of a MOS transistor to be connected to a storage node because of the reduction in dimensions. In this case, if the static memory cell is irradiated with radiation from the outside, electron-hole pairs are generated in a semiconductor substrate along the path of radiation, and at least the electrons or holes of the electron-hole pairs flow into a diffusion layer that forms the drain, causing data inversion. Thus, a soft-error phenomenon occurs in that data cannot be correctly held. The soft-error phenomenon has become a serious problem in recent static memory cells whose sizes have been reduced because as the decrease in the size of memory cells increases, the reduction in the gate capacitance or diffusion layer capacitance of the MOS transistor to be connected to the storage node becomes more noticeable than the electron-hole pairs generated by radiation. Therefore, it has been reported that a capacitor is formed in a storage node of a static memory cell to ensure sufficient electrical charges in the storage node so that the occurrence of soft errors can be avoided to ensure operational stability (Japanese Unexamined Patent Application Publication No. 2008-227344). SUMMARY OF THE INVENTION Accordingly, the present invention provides a high-degree-of-integration, operational stability-secured static memory cell using an SGT. In an aspect of the present invention, a semiconductor device includes a static memory cell having six MOS transistors arranged on a substrate. The six MOS transistors include first and second NMOS access transistors for accessing a memory, third and fourth NMOS driver transistors for driving a storage node that holds data of the memory cell, and first and second PMOS load transistors that supply charges for holding the data of the memory cell. Each of the first and second NMOS access transistors for accessing the memory has a first diffusion layer, a pillar-shaped semiconductor layer, and a second diffusion layer arranged vertically with respect to the substrate in a hierarchical manner so that the pillar-shaped semiconductor layer is arranged between the first diffusion layer and the second diffusion layer, and the pillar-shaped semiconductor layer has a side wall on which a gate is formed. Each of the third and fourth NMOS driver transistors for driving the storage node that holds the data of the memory cell has a third diffusion layer, a pillar-shaped semiconductor layer, and a fourth diffusion layer arranged vertically with respect to the substrate in a hierarchical manner so that the pillar-shaped semiconductor layer is arranged between the third diffusion layer and the fourth diffusion layer, and the pillar-shaped semiconductor layer has a side wall on which a gate is formed. Each of the first and second PMOS load transistors that supply the charges for holding the data of the memory cell has a fifth diffusion layer, a pillar-shaped semiconductor layer, and a sixth diffusion layer arranged vertically with respect to the substrate in a hierarchical manner so that the pillar-shaped semiconductor layer is arranged between the fifth diffusion layer and the sixth diffusion layer, and the pillar-shaped semiconductor layer has a side wall on which a gate is formed. The first diffusion layers, the third diffusion layers, and the fifth diffusion layers are arranged so as to be electrically insulated from the substrate. A length between an upper end of the third diffusion layer and a lower end of the fourth diffusion layer of each of the third and fourth NMOS driver transistors is shorter than a length between an upper end of the first diffusion layer and a lower end of the second diffusion layer of each of the first and second NMOS access transistors. In another aspect of the present invention, a semiconductor device includes a static memory cell having six MOS transistors arranged on a substrate. The six MOS transistor include first and second NMOS access transistors for accessing a memory, third and fourth NMOS driver transistors that drive a storage node for holding data of the memory cell, and first and second PMOS load transistors that supply charges for holding the data of the memory cell. Each of the first and second NMOS access transistors for accessing the memory has a first diffusion layer, a pillar-shaped semiconductor layer, and a second diffusion layer arranged vertically with respect to the substrate in a hierarchical manner so that the pillar-shaped semiconductor layer is arranged between the first diffusion layer and the second diffusion layer, and the pillar-shaped semiconductor layer has a side wall on which a gate is formed. Each of the third and fourth NMOS driver transistors for driving the storage node that holds the data of the memory cell has a third diffusion layer, a pillar-shaped semiconductor layer, and a fourth diffusion layer arranged vertically with respect to the substrate in a hierarchical manner so that the pillar-shaped semiconductor layer is arranged between the third diffusion layer and the fourth diffusion layer, and the pillar-shaped semiconductor layer has a side wall on which a gate is formed. Each of the first and second PMOS load transistors that supply the charges for holding the data of the memory cell has a fifth diffusion layer, a pillar-shaped semiconductor layer, and a sixth diffusion layer arranged vertically with respect to the substrate in a hierarchical manner so that the pillar-shaped semiconductor layer is arranged between the fifth diffusion layer and the sixth diffusion layer, and the pillar-shaped semiconductor layer has a side wall on which a gate is formed. The first diffusion layers, the third diffusion layers, and the fifth diffusion layers are arranged so as to be electrically insulated from the substrate. A length between an upper end of the third diffusion layer and a lower end of the fourth diffusion layer of each of the third and fourth NMOS driver transistors is shorter than a length between an upper end of the fifth diffusion layer and a lower end of the sixth diffusion layer of each of the first and second PMOS load transistors. Preferably, the length between the upper end of the first diffusion layer and the lower end of the second diffusion layer of each of the first and second NMOS access transistors is within a range of 1.3 times to three times the length between the upper end of the third diffusion layer and the lower end of the fourth diffusion layer of each of the third and fourth NMOS driver transistors. Preferably, the length between the upper end of the fifth diffusion layer and the lower end of the sixth diffusion layer of each of the first and second PMOS load transistors is within a range of 1.3 times to three times the length between the upper end of the third diffusion layer and the lower end of the fourth diffusion layer of each of the third and fourth NMOS driver transistors. Lengths from lower ends to upper ends of the gates can be the same. The upper end of the third diffusion layer of each of the third and fourth NMOS driver transistors can be at a position higher than the upper end of the first diffusion layer of each of the first and second NMOS access transistors. The lower end of the fourth diffusion layer of each of the third and fourth NMOS driver transistors can be at a position lower than the lower end of the second diffusion layer of each of the first and second NMOS access transistors. The upper end of the third diffusion layer of each of the third and fourth NMOS driver transistors can be at a position higher than the upper end of the first diffusion layer of each of the first and second NMOS access transistors, and the lower end of the fourth diffusion layer of each of the third and fourth NMOS driver transistors can be at a position lower than the lower end of the second diffusion layer of each of the first and second NMOS access transistors. The first diffusion layer of each of the first and second NMOS access transistors can be formed after the third diffusion layer of each of the third and fourth NMOS driver transistors is formed. The fourth diffusion layers of the third and fourth NMOS driver transistors and the second diffusion layers of the first and second NMOS access transistors can be formed by ion implantation. Further, energy of ion implantation for forming the fourth diffusion layer of each of the third and fourth NMOS driver transistors can be higher than energy of ion implantation for forming the second diffusion layer of each of the first and second NMOS access transistors. The fourth diffusion layers of the third and fourth NMOS driver transistors can include phosphorus. According to the present invention, a high-degree-of-integration, operational stability-secured static memory cell in which the channel length of a driver transistor can be shorter than the channel length of an access transistor, and a method for fabricating the static memory cell can be provided. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a plan view of a static memory cell according to first and second embodiments of the present invention; FIG. 1B is a cross-sectional view taken along line X-X′ in FIG. 1A ; FIG. 2A is a cross-sectional view of a static memory cell according to third and fifth embodiments of the present invention; FIG. 2B is a cross-sectional view of a static memory cell according to fourth and sixth embodiments of the present invention; FIG. 3 is a cross-sectional view of a static memory cell according to a seventh embodiment of the present invention; FIG. 4 is a cross-sectional view of a static memory cell according to an eighth embodiment of the present invention; FIG. 5 is a cross-sectional view of a static memory cell according to a ninth embodiment of the present invention; FIG. 6 is a cross-sectional view of a static memory cell according to a tenth embodiment of the present invention; FIG. 7 is a cross-sectional view explaining a method for fabricating a static memory cell according to an embodiment of the present invention; FIG. 8 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 9 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 10 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 11 is a cross-sectional view explaining the method for fabricating of a static memory cell according to the embodiment of the present invention; FIG. 12 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 13 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 14 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 15 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 16 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 17 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 18 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 19 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 20 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 21 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 22 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 23 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 24 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 25 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 26 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 27 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 28 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 29 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 30 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 31 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 32 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 33 is a cross-sectional view explaining a method for fabricating a static memory cell according to another embodiment of the present invention; FIG. 34 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 35 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 36 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 37 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 38 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 39 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 40 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 41 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 42 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 43 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 44 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 45 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 46 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 47 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 48 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 49 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 50 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 51 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 52 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 53 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 54 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 55 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 56 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; FIG. 57 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention; and FIG. 58 is a cross-sectional view explaining the method for fabricating a static memory cell according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described hereinafter with reference to the drawings. It is to be understood that the present invention is not to be limited to the following embodiments. FIGS. 1A and 1B illustrate a plan view and a cross-sectional view of a static memory cell according to a first embodiment of the present invention, respectively. A third NMOS driver transistor 101 has a third diffusion layer 119 , a pillar-shaped semiconductor layer 149 , and a fourth diffusion layer 107 . A gate 125 is formed on side walls of the pillar-shaped semiconductor layer 149 , a portion of the fourth diffusion layer 107 , and a portion of the third diffusion layer 119 of the third NMOS driver transistor 101 via a gate insulating film 113 . A first NMOS access transistor 103 has a first diffusion layer 121 , a pillar-shaped semiconductor layer 151 , and a second diffusion layer 109 . A gate 126 is formed on side walls of the pillar-shaped semiconductor layer 151 , a portion of the second diffusion layer 109 , and a portion of the first diffusion layer 121 of the first NMOS access transistor 103 via a gate insulating film 115 . The gate height of the gate 125 is low in the vicinity of the third NMOS driver transistor 101 , and the physical gate length of the gate 125 is shorter than that of the gate 126 . The length between the first diffusion layer 121 and the second diffusion layer 109 of the first NMOS access transistor 103 is twice the length between the third diffusion layer 119 and the fourth diffusion layer 107 of the third NMOS driver transistor 101 . Therefore, the current driving force of the driver transistor can be made double the current driving force of the access transistor without increasing the area, and operational stability can be ensured. A first PMOS load transistor 102 has a fifth diffusion layer 120 , a pillar-shaped semiconductor layer 150 , and a sixth diffusion layer 108 . The gate 125 is formed on side walls of the pillar-shaped semiconductor layer 150 , a portion of the fifth diffusion layer 120 , and a portion of the sixth diffusion layer 108 of the first PMOS load transistor 102 via a gate insulating film 114 . The third NMOS driver transistor 101 and the first PMOS load transistor 102 are connected to each other via the gate 125 . Further, the third diffusion layer 119 , the fifth diffusion layer 120 , and the first diffusion layer 121 are connected to one another via a silicide layer (not illustrated in the drawings). In the drawings, a silicon-on-insulator (SOI) substrate is used to electrically insulate the third diffusion layer 119 , the fifth diffusion layer 120 , and the first diffusion layer 121 from a substrate; however, any other method that can provide electrical insulation may be used. For example, a PN junction may be formed using a Si substrate and electrical insulation may be formed using the reverse bias state of the PN junction. A fourth NMOS driver transistor 106 has a third diffusion layer 124 , a pillar-shaped semiconductor layer, and a fourth diffusion layer 112 . A gate 128 is formed on side walls of the pillar-shaped semiconductor layer, a portion of the third diffusion layer 124 , and a portion of the fourth diffusion layer 112 of the fourth NMOS driver transistor 106 via a gate insulating film 118 . A second NMOS access transistor 104 has a first diffusion layer 122 , a pillar-shaped semiconductor layer, and a second diffusion layer 110 . A gate 127 is formed on side walls of the pillar-shaped semiconductor layer, a portion of the first diffusion layer 122 , and a portion of the second diffusion layer 110 of the second NMOS access transistor 104 via a gate insulating film 116 . Although not illustrated in the drawings, the length between the first diffusion layer 122 and the second diffusion layer 110 of the second NMOS access transistor 104 is twice the length between the third diffusion layer 124 and the fourth diffusion layer 112 of the fourth NMOS driver transistor 106 . A second PMOS load transistor 105 has a fifth diffusion layer 123 , a pillar-shaped semiconductor layer, and a sixth diffusion layer 111 . The gate 128 is formed on side walls of the pillar-shaped semiconductor layer, a portion of the fifth diffusion layer 123 , and a portion of the sixth diffusion layer 111 of the second PMOS load transistor 105 via a gate insulating film 117 . The fourth NMOS driver transistor 106 and the second PMOS load transistor 105 are connected to each other via the gate 128 . Further, the first diffusion layer 122 , the fifth diffusion layer 123 , and the third diffusion layer 124 are connected to one another via a silicide layer (not illustrated in the drawings). In the drawings, an SOI substrate is used to electrically insulate the first diffusion layer 122 , the fifth diffusion layer 123 , and the third diffusion layer 124 from the substrate; however, any other method that can provide electrical insulation may be used. For example, a PN junction may be formed using a Si substrate and electrical insulation may be formed using the reverse bias state of the PN junction. A contact 130 is formed on the gate 125 , and a contact 137 is formed on the first diffusion layer 122 and the fifth diffusion layer 123 . The contacts 130 and 137 are connected to each other via a metal 142 . Further, a contact 139 is formed on the gate 128 , and a contact 132 is formed on the fifth diffusion layer 120 and the first diffusion layer 121 . The contacts 139 and 132 are connected to each other via a metal 144 . A contact 131 is formed on the sixth diffusion layer 108 , and a contact 138 is formed on the sixth diffusion layer 111 . A metal 143 is connected to the contacts 131 and 138 , and power is supplied. A contact 129 is formed on the fourth diffusion layer 107 , a metal 141 is formed, and power is supplied. A contact 140 is formed on the fourth diffusion layer 112 , a metal 148 is formed, and power is supplied. A contact 133 is formed on the second diffusion layer 109 , and a metal 145 is formed, which serves as a bit line. A contact 136 is formed on the second diffusion layer 110 , and a metal 210 is formed, which serves as a bit line. A contact 134 is formed on the gate 126 , and a metal 146 is formed, which serves as a word line. A contact 135 is formed on the gate 127 , and a metal 147 is formed, which serves as a word line. The plan view and the cross-sectional view of a static memory cell according to a second embodiment of the present invention are the same as those illustrated in FIG. 1 . In the second embodiment, the length between the third diffusion layer 119 and the fourth diffusion layer 107 of the third NMOS driver transistor 101 is shorter than the length between the fifth diffusion layer 120 and the sixth diffusion layer 108 of the first PMOS load transistor 102 . In an SRAM, a PMOS load transistor is formed with a minimum size and is formed so that the current driving force of the PMOS load transistor is smaller than the current driving force of an NMOS access transistor. That is, an NMOS access transistor and a PMOS load transistor are formed so as to have the same channel length. Therefore, in the present invention, the channel length of the NMOS driver transistor 101 is shorter than the channel length of the PMOS driver transistor 102 . FIGS. 2A and 2B illustrate cross-sectional views of static memory cells according to third and fourth embodiments of the present invention, respectively. In FIG. 2A , the length between the upper end of the first diffusion layer 121 of the first NMOS access transistor 103 and the lower end of the second diffusion layer 109 of the first NMOS access transistor 103 is made 1.3 times the length between the upper end of the third diffusion layer 119 of the third NMOS driver transistor 101 and the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 . In FIG. 2B , the length between the upper end of the first diffusion layer 121 of the first NMOS access transistor 103 and the lower end of the second diffusion layer 109 of the first NMOS access transistor 103 is made three times the length between the upper end of the third diffusion layer 119 of the third NMOS driver transistor 101 and the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 . As the channel length of a driver transistor decreases, operational stability can be ensured, whereas if the channel length is short, the short-channel effects arise, which prevents the transistor from being cut off. Therefore, by way of example, the range from 1.3 times to three times, as described above, can ensure operational stability and can suppress or reduce short-channel effects, where the range may be selected as desired in accordance with the actual demand. The cross-sectional views of static memory cells according to fifth and sixth embodiments of the present invention are the same as those in FIGS. 2A and 2B , respectively. In the fifth embodiment, the length between the upper end of the fifth diffusion layer 120 of the first PMOS load transistor 102 and the lower end of the sixth diffusion layer 108 of the first PMOS load transistor 102 , is made 1.3 times the length between the upper end of the third diffusion layer 119 of the third NMOS driver transistor 101 and the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 . In the sixth embodiment, the length between the upper end of the fifth diffusion layer 120 of the first PMOS load transistor 102 and the lower end of the sixth diffusion layer 108 of the first PMOS load transistor 102 is three times the length between the upper end of the third diffusion layer 119 of the third NMOS driver transistor 101 and the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 . As the channel length of a driver transistor decreases, operational stability can be ensured, whereas if the channel length is short, the short-channel effects arise, which prevents the transistor from being cut off. Therefore, by way of example, the range from 1.3 times to three times, as described above, can ensure operational stability and can suppress or reduce short-channel effects, where the range may be selected as desired in accordance with the actual demand. FIG. 3 illustrates a cross-sectional view of a static memory cell according to a seventh embodiment of the present invention. The physical gate lengths of the gates 125 and 126 are made the same. Since the lengths from the lower ends to the upper ends of the gates 125 and 126 , that is, the physical gate lengths, are the same, the SGT production method described above can be used of forming a pillar-shaped semiconductor layer, depositing a gate conductive film on the pillar-shaped semiconductor layer, performing planarization, and then etching back the gate conductive film to obtain a desired length. In general, reducing the channel length is equivalent to reducing the physical gate length, as in FIG. 1 . If the physical gate length is reduced, the gate capacitance is reduced. If the gate capacitance is reduced, a soft error occurs, resulting in operational stability not being ensured. In FIG. 3 , in contrast, the physical gate lengths are the same while only the channel length of a driver transistor is reduced. Therefore, the gate capacitance is not reduced although the current driving force of the driver transistor is doubled. That is, the current driving force of a driver transistor can be made double the current driving force of an access transistor, resulting in operational stability being ensured. In addition, the occurrence of soft errors can be avoided to ensure operational stability. FIG. 4 illustrates a cross-sectional view of a static memory cell according to an eighth embodiment of the present invention. In the embodiment illustrated in FIG. 4 , the physical gate lengths are the same, and the upper end of the third diffusion layer 119 of the third NMOS driver transistor 101 is at a higher portion than the upper end of the first diffusion layer 121 of the first NMOS access transistor 103 . This enables the third NMOS driver transistor 101 to increase the overlap capacitance between the gate 125 and the third diffusion layer 119 . During the cut-off of the third NMOS driver transistor 101 , the overlap capacitance between the gate 125 and the third diffusion layer 119 becomes a parasitic capacitance parasitic to a storage node. Since the overlap capacitance is large, the occurrence of soft errors can further be avoided to ensure operational stability. FIG. 5 illustrates a cross-sectional view of a static memory cell according to a ninth embodiment of the present invention. The difference between FIG. 5 and FIG. 4 is that the upper end of the third diffusion layer 119 of the third NMOS driver transistor 101 is positioned at the same height as the upper end of the first diffusion layer 121 of the first NMOS access transistor 103 and that the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 is at a position lower than the lower end of the second diffusion layer 109 of the first NMOS access transistor 103 . Also in the embodiment illustrated in FIG. 5 , the physical gate lengths are the same while only the channel length of a driver transistor is reduced. Therefore, the gate capacitance is not reduced although the current driving force of the driver transistor is doubled. Thus, the current driving force of a driver transistor can be made double the current driving force of an access transistor, resulting in operational stability being ensured. In addition, the occurrence of soft errors can be avoided to ensure operational stability. However, further advantages illustrated in FIG. 4 , that is, the advantages that during the cut-off of the third NMOS driver transistor 101 , the overlap capacitance between the gate 125 and the third diffusion layer 119 becomes a parasitic capacitance parasitic to a storage node and that since the overlap capacitance is large, the occurrence of soft errors can further be avoided to ensure operational stability, are not achievable. However, if a storage node is designed to be located above a transistor, the advantage of further avoiding the occurrence of soft errors can be achieved. As described below with respect to a production method, the creation of the configuration illustrated in FIG. 4 requires a comparatively long heat treatment to be performed after ion implantation for the third diffusion layer 119 . When the fourth diffusion layer 107 is to be formed by ion implantation, the energy of the implantation is increased or phosphorus with a long diffusion length is used, thus enabling the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 to be at a position lower than the lower end of the second diffusion layer 109 of the first NMOS access transistor 103 . That is, the duration of heat treatment can be shorter than that in FIG. 4 . FIG. 6 illustrates a cross-sectional view of a static memory cell according to a tenth embodiment of the present invention. The difference between FIG. 6 and FIG. 4 is that the upper end of the third diffusion layer 119 of the third NMOS driver transistor 101 is at a position higher than the upper end of the first diffusion layer 121 of the first NMOS access transistor 103 and that the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 is at a position lower than the lower end of the second diffusion layer 109 of the first NMOS access transistor 103 . Also in the embodiment illustrated in FIG. 6 , the channel length of a driver transistor is made shorter than the channel length of an access transistor, thus enabling operational stability to be ensured. Additionally, an advantage illustrated in FIG. 4 , that is, the advantage of avoiding the occurrence of soft errors, can also be achieved. Since the diffusion length of the third diffusion layer 119 is short, the duration of heat treatment shorter than that required to create the configuration illustrated in FIG. 4 is required for formation. When the fourth diffusion layer 107 is to be formed by ion implantation, the energy of the implantation is increased or phosphorus with a diffusion length is used, thus enabling the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 to be at a position lower than the lower end of the second diffusion layer 109 of the first NMOS access transistor 103 . That is, the duration of heat treatment can be shorter than that required in FIG. 4 , and the occurrence of soft errors can also be avoided. However, a larger number of steps in the production process than that required to create the configuration illustrated in FIG. 4 or the configuration illustrated in FIG. 5 are required. While various embodiments have been illustrated, any of them may be selected as desired in accordance with the actual demand. An example of a production process for forming the structure of the static memory cell illustrated in FIG. 4 according to an embodiment of the present invention will be described with reference to FIGS. 7 to 32 . FIG. 7 illustrates a state where an oxide film 157 is formed on a silicon layer 152 , a planar silicon layer 158 is formed on the oxide film 157 , and pillar-shaped silicon layers 159 , 160 , and 161 having nitride film hard masks 162 , 163 , and 164 in upper portions thereof are formed. In the state illustrated in FIG. 7 , an oxide film is deposited and is etched back to form oxide film sidewalls 165 , 166 , and 167 , as illustrated in FIG. 8 . After that, a resist 168 for forming a third diffusion layer 119 is formed. In this state, as illustrated in FIG. 9 , arsenic is implanted to form the third diffusion layer 119 . After that, as illustrated in FIG. 10 , the resist 168 is stripped, the oxide film sidewalls 165 , 166 , and 167 are stripped, and the first heat treatment is carried out. Further, as illustrated in FIG. 11 , oxide film sidewalls 169 , 170 , and 171 are formed. After that, a resist 172 for forming a first diffusion layer 121 is formed. In this state, as illustrated in FIG. 12 , arsenic is implanted to form the first diffusion layer 121 . After that, as illustrated in FIG. 13 , the resist 172 is stripped, the oxide film sidewalls 169 , 170 , and 171 are stripped, and the second heat treatment is carried out. Since the third diffusion layer 119 undergoes heat treatment twice, the upper end of the third diffusion layer 119 is made to be at a position higher than the upper end of the first diffusion layer 121 . Therefore, the channel length of a driver transistor is made shorter than the channel length of an access transistor, and operational stability can be ensured. Subsequently, as illustrated in FIG. 14 , oxide film sidewalls 173 , 174 , and 175 are formed. After that, a resist 176 for forming a fifth diffusion layer 120 is formed. In this state, as illustrated in FIG. 15 , boron is implanted to form the fifth diffusion layer 120 . After the above state, as illustrated in FIG. 16 , the resist 176 is stripped, the oxide film sidewalls 173 , 174 , and 175 are stripped, and heat treatment is carried out. After that, as illustrated in FIG. 17 , a resist for forming elements separately is formed, silicon etching is performed, and the resist is stripped. Subsequently, as illustrated in FIG. 18 , an oxide film 153 is formed so as to be buried in spaces between the elements. After that, an atmospheric pressure chemical vapor deposition (CVD) oxide film is deposited and is etched back to form an oxide film 177 . In this case, oxide films 178 , 179 , and 180 remain on the nitride film hard masks 162 , 163 , and 164 , respectively. Further, as illustrated in FIG. 19 , gate insulating films 113 , 114 , and 115 are formed, a gate conductive film 181 is deposited, and planarization is performed. After the oxide films 178 , 179 , and 180 are exposed, the oxide films 178 , 179 , and 180 are etched, and planarization is further performed using the nitride film hard masks 162 , 163 , and 164 as stoppers. Each of the gate insulating films 113 , 114 , and 115 is one of an oxide film, a nitride film, an oxynitride film, and a high-dielectric film. The gate conductive film 181 is one of a polysilicon film, a metal/polysilicon laminated film, and a metal film. Subsequently, as illustrated in FIG. 20 , the gate conductive film 181 is etched back to obtain a desired physical gate length. Consequently, the physical gate length is made uniform over all the transistors. Then, an oxide film is deposited, a nitride film is deposited, and etching is performed to make the oxide film and the nitride film remain as sidewalls. As illustrated in FIG. 21 , an insulating film sidewall composed of an oxide film 184 and a nitride film 185 , an insulating film sidewall composed of an oxide film 186 and a nitride film 187 , and an insulating film sidewall composed of an oxide film 188 and a nitride film 189 are formed. Subsequently, as illustrated in FIG. 22 , resists 182 and 183 for performing gate etching are formed. Then, as illustrated in FIG. 23 , the gate conductive film 181 is etched to from gates 125 and 126 , and the oxide film 177 is etched to form oxide films 154 and 155 . Then, the resists 182 and 183 are stripped. Subsequently, as illustrated in FIG. 24 , the insulating film sidewall composed of the oxide film 184 and the nitride film 185 , the insulating film sidewall composed of the oxide film 186 and the nitride film 187 , and the insulating film sidewall composed of the oxide film 188 and the nitride film 189 are etched. Then, a nitride film is deposited, and etching is performed to make the nitride film remain as sidewalls. As illustrated in FIG. 25 , nitride film sidewalls 190 , 191 , 192 , 193 , and 194 are formed. Subsequently, as illustrated in FIG. 26 , a resist 195 for forming a fourth diffusion layer 107 and a second diffusion layer 109 is formed. Then, as illustrated in FIG. 27 , arsenic is ion-implanted to form the fourth diffusion layer 107 and the second diffusion layer 109 . After that, as illustrated in FIG. 28 , the resist 195 is stripped, and heat treatment is carried out. As illustrated in FIG. 29 , a resist 196 for forming a sixth diffusion layer 108 is formed. Subsequently, as illustrated in FIG. 30 , boron is ion-implanted to form the sixth diffusion layer 108 . Then, as illustrated in FIG. 31 , the resist 196 is stripped, and heat treatment is carried out. Subsequently, as illustrated in FIG. 32 , an interlayer film 156 is deposited, contacts 129 , 130 , 131 , 132 , 133 , and 134 are formed, and metals 141 , 142 , 143 , 144 , 145 , and 146 are formed. Before an interlayer film is formed, silicide layers may be formed on the third diffusion layer 119 , the fifth diffusion layer 120 , and the first diffusion layer 121 . Silicide layers may also be formed on the fourth diffusion layer 107 , the sixth diffusion layer 108 , and the second diffusion layer 109 . Accordingly, the channel length of a driver transistor is made shorter than the channel length of an access transistor to ensure operational stability. Furthermore, the physical gate length of the driver transistor and the physical gate length of the access transistor are made the same, and therefore the SGT production method described above can be used. That is, the current driving force of the driver transistor can be made double the current driving force of the access transistor to ensure operational stability. Furthermore, only the channel length of the driver transistor is reduced while the physical gate lengths are the same. Therefore, the gate capacitance is not reduced although the current driving force of the driver transistor is doubled. Thus, the occurrence of soft errors can be avoided to ensure operational stability. Additionally, the upper end of the third diffusion layer of the driver transistor is made to be at position higher than the upper end of the first diffusion layer of the access transistor, thus allowing the driver transistor to increase the overlap capacitance between the gate and the third diffusion layer. The occurrence of soft errors can further be avoided to ensure further operational stability. A production method for forming the above structure has been illustrated. An example of a production process for forming the structure of the static memory cell illustrated in FIG. 5 according to an embodiment of the present invention will be described with reference to FIGS. 33 to 58 . FIG. 33 illustrates a structure in which an oxide film 157 is formed on a silicon layer 152 , a planar silicon layer 158 is formed on the oxide film 157 , and pillar-shaped silicon layers 159 , 160 , and 161 having nitride film hard masks 162 , 163 , and 164 in upper portions thereof are formed. Subsequently, as illustrated in FIG. 34 , an oxide film is deposited and is etched back to form oxide film sidewalls 169 , 170 , and 171 . After that, a resist 172 for forming a third diffusion layer 119 and a first diffusion layer 121 is formed. Then, as illustrated in FIG. 35 , arsenic is implanted to form the third diffusion layer 119 and the first diffusion layer 121 . Subsequently, as illustrated in FIG. 36 , the resist 172 is stripped, the oxide film sidewalls 169 , 170 , and 171 are stripped, and heat treatment is carried out. Then, as illustrated in FIG. 37 , oxide film sidewalls 173 , 174 , and 175 are formed. After that, a resist 176 for forming a fifth diffusion layer 120 is formed. Subsequently, as illustrated in FIG. 38 , boron is implanted to form the fifth diffusion layer 120 . After that, as illustrated in FIG. 39 , the resist 176 is stripped, the oxide film sidewalls 173 , 174 , and 175 are stripped, and heat treatment is carried out. Subsequently, as illustrated in FIG. 40 , a resist for forming elements separately is formed, silicon etching is performed, and the resist is stripped. Then, as illustrated in FIG. 41 , an oxide film 153 is formed so as to be buried in spaces between the elements. After that, an atmospheric pressure CVD oxide film is deposited and is etched back to form an oxide film 177 . In this case, oxide films 178 , 179 , and 180 remain on the nitride film hard masks 162 , 163 , and 164 , respectively. After that, as illustrated in FIG. 42 , gate insulating films 113 , 114 , and 115 are formed, a gate conductive film 181 is deposited, and planarization is performed. After the oxide films 178 , 179 , and 180 are exposed, the oxide films 178 , 179 , and 180 are etched, and planarization is further performed using the nitride film hard masks 162 , 163 , and 164 as stoppers. Each of the gate insulating films 113 , 114 , and 115 is one of an oxide film, a nitride film, an oxynitride film, and a high-dielectric film. The gate conductive film 181 is one of a polysilicon film, a metal/polysilicon laminated film, and a metal film. Subsequently, as illustrated in FIG. 43 , the gate conductive film 181 is etched back to obtain a desired physical gate length. Consequently, the physical gate length is made uniform over all the transistors. Then, as illustrated in FIG. 44 , an oxide film is deposited, a nitride film is deposited, and etching is performed to make the oxide film and the nitride film remain as sidewalls. An insulating film sidewall composed of an oxide film 184 and a nitride film 185 , an insulating film sidewall composed of an oxide film 186 and a nitride film 187 , and an insulating film sidewall composed of an oxide film 188 and a nitride film 189 are formed. Further, as illustrated in FIG. 45 , resists 182 and 183 for performing gate etching are formed. Then, as illustrated in FIG. 46 , the gate conductive film 181 is etched to form gates 125 and 126 , and the oxide film 177 is etched to form oxide films 154 and 155 . Then, the resists 182 and 183 are stripped. After that, as illustrated in FIG. 47 , the insulating film sidewall composed of the oxide film 184 and the nitride film 185 , the insulating film sidewall composed of the oxide film 186 and the nitride film 187 , and the insulating film sidewall composed of the oxide film 188 and the nitride film 189 are etched. Subsequently, as illustrated in FIG. 48 , a nitride film is deposited and etching is performed to make the nitride film remain as sidewalls to form nitride film sidewalls 190 , 191 , 192 , 193 , and 194 . Then, as illustrated in FIG. 49 , a resist 201 for forming a fourth diffusion layer 107 is formed. Subsequently, as illustrated in FIG. 50 , arsenic or phosphorus is ion-implanted to form the fourth diffusion layer 107 . When arsenic is to be used, the energy of the ion implantation may be increased. In addition, phosphorus having a long diffusion length is used, thus enabling the lower end of the fourth diffusion layer 107 of the third NMOS driver transistor 101 to be at a position lower than the lower end of the second diffusion layer 109 of the first NMOS access transistor 103 . Whether to use arsenic or phosphorus may be selected as desired. After that, as illustrated in FIG. 51 , the resist 201 is stripped, and heat treatment is carried out. Then, as illustrated in FIG. 52 , a resist 202 for forming a second diffusion layer 109 is formed. Subsequently, as illustrated in FIG. 53 , arsenic is ion-implanted to from the second diffusion layer 109 . Subsequently, as illustrated in FIG. 54 , the resist 202 is stripped, and heat treatment is carried out. Subsequently, as illustrated in FIG. 55 , a resist 203 for forming a sixth diffusion layer 108 is formed. Subsequently, as illustrated in FIG. 56 , boron is ion-implanted to form the sixth diffusion layer 108 . Subsequently, as illustrated in FIG. 57 , the resist 203 is stripped, and heat treatment is carried out. Then, as illustrated in FIG. 58 , an interlayer film 156 is deposited, contacts 129 , 130 , 131 , 132 , 133 , and 134 are formed, and metals 141 , 142 , 143 , 144 , 145 , and 146 are formed. Before an interlayer film is formed, silicide layers may be formed on the third diffusion layer 119 , the fifth diffusion layer 120 , and the first diffusion layer 121 . Silicide layers may also be formed on the fourth diffusion layer 107 , the sixth diffusion layer 108 , and the second diffusion layer 109 . Accordingly, the channel length of a driver transistor is made shorter than the channel length of an access transistor to ensure operational stability, and the duration of heat treatment can be shorter than that in FIG. 4 . While production methods for forming the structures illustrated in FIG. 4 and FIG. 5 have been described, the structure illustrated in FIG. 6 can be formed by using a combination of the method of forming the third diffusion layer 119 and the first diffusion layer 121 illustrated in FIG. 4 and the method of forming the fourth diffusion layer 107 and the second diffusion layer 109 illustrated in FIG. 5 . A variety of embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. The foregoing embodiments serve to explain exemplary embodiments of the present invention, and the technical scope of the present invention is not to be limited to the foregoing embodiments.

A semiconductor memory device includes a static memory cell having six MOS transistors arranged on a substrate. The six MOS transistors include first and second NMOS access transistors, third and fourth NMOS driver transistors, and first and second PMOS load transistors. Each of the first and second NMOS access transistors has a first diffusion layer, a pillar-shaped semiconductor layer, and a second diffusion layer arranged vertically on the substrate in a hierarchical manner. Each of the third and fourth NMOS driver transistors has a third diffusion layer, a pillar-shaped semiconductor layer, and a fourth diffusion layer arranged vertically on the substrate in a hierarchical manner. The lengths between the upper ends of the third diffusion layers and the lower ends of the fourth diffusion layers are shorter than the lengths between the upper ends of the first diffusion layer and the lower ends of the second diffusion layers.

FIELD OF THE INVENTION The present invention relates to downhole tools. More specifically, the invention relates to tools run into a wellbore and apparatus and methods to facilitate their insertion. More particularly still, the invention relates to a centering device having friction reducing members to reduce contact of a tool with the walls of a non-vertical wellbore. The invention also facilitates “pumping” a tool into a wellbore with fluid when gravity is not available. BACKGROUND OF THE INVENTION Various operations require tools to be inserted into a well and fixed there temporarily. In some instances, packers are run into a wellbore and then set using slips and cones that fix the packer at a predetermined location to isolate an annular area of the bore. In other instances, bridge plugs or “frac” plugs are similarly installed to temporarily block the wellbore and provide a barrier against which pressure can be developed to treat a hydrocarbon-bearing formation adjacent the wellbore. In all of these instances, the tool is typically disconnected from a run-in string of tubulars and left in place during the operation. Thereafter, some of the tools can be retrieved to the surface while others must be destroyed with a milling device. Increasingly, hydrocarbons are collected from wellbores that are not vertical but extend outward, sometimes horizontally from a central wellbore. These non-vertical wellbores are cased and completed just like their vertical counterparts and are also subject to the same treatments and tools. Tools can always be run into a non-vertical wellbore on rigid tubing but that requires a rig and complimentary equipment to connect the tubing as it is inserted and removed from the wellbore. Coil tubing is thin-walled, removable, continuous tubing without joints. Coil tubing is available for running tools into a well but must be transferred to the well site on large reels and then requires some type of injector to be installed in the wellbore. Because of the above disadvantages of tubing, the preferred way to install many downhole tools is with wireline. Wireline is a cable comprising one or more conductors which provides real-time communication with a downhole tool and can also bear the weight of the tool. Wireline is designed to be reeled into a wellbore with the tool on one end. In operations requiring many tools to be placed in the wellbore, like fracturing operations including multiple zones, wireline installation saves time and money. Problems with wireline installations arise with non-vertical wellbores simply because gravity is not available to help urge the tool down the wellbore. Rather than move along the center of the wellbore, the tools tend to rest on the low side of the bore, coming into contact with any debris that has settled there. Various means have been used to overcome the problem of wireline delivered tools and non-vertical wellbores. In some instances the tools are “pumped down” with fluid pumped past the tool. This is partially effective but due to the position of the tool on the low side of the wellbore, a large annular gap extends between the top of the tool and the upper wall of the wellbore, making the pumping process partially ineffective. In other instances, tractors are used to help move a tool along a non-vertical portion of a wellbore. Tractors typically have at least one moving member that either rotates or oscillates against a wellbore wall. However, tractors are expensive, cannot be left in a well and add another layer of complication to a tool installation job. There is a need therefore for a method and apparatus that can facilitate the installation of a tool into a wellbore, particularly a non-vertical portion of a wellbore. There is a further need for a tool that has a friction-reducing component to reduce the friction that necessarily arises as the tool moves along a non-vertical wellbore. There is a further need for a tool that has centering capabilities to reduce its tendency to sit on a low side of a non-vertical wellbore. There is yet a further need for a tool that can better utilize an annular area created between the tool and the wellbore to facilitate pumping down the tool with circulating fluids. SUMMARY OF THE INVENTION The invention relates to a system for facilitating the insertion of a tool into a wellbore, especially a non-vertical wellbore. In one embodiment a tool is fixable in a wellbore and includes centralizing, friction-reducing members that serve to keep the body of the tool off the walls of the wellbore wall. In another embodiment the tool includes a wiper ring that partially fills an annular area formed between the centered tool and the wellbore walls. The surface of the ring facing the upper end of the wellbore provides fluid resisting piston surface and permits the centered tool to be pumped down the wellbore more effectively. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. FIG. 1 is a view, partially in section of a wellbore, showing a tool being run in on wireline. FIG. 2 is a section view of a tool including the centralizing, friction reducing members of the present invention. FIG. 3 is a section view of the tool of FIG. 2 after it has been set in the wellbore. FIG. 4 is a section view of the tool along a line 4 - 4 of FIG. 3 . FIG. 5 is section view of another tool showing additional embodiments of the invention. FIG. 6 is an end view of FIG. 5 . FIG. 7 is an enlarged section view illustrating the flow of the fluid through and around the tool of FIG. 5 as it is being pumped down a wellbore. DETAILED DESCRIPTION FIG. 1 shows a typical completed well with a wellbore 100 , a wellhead 105 , a vertical wellbore section 107 and a non-vertical wellbore section 110 . The wellbore is lined with casing 112 . Installed over the well is a rig 115 placed there to facilitate the insertion of a tool or tools into the wellbore. A truck 120 is shown with a reel 122 of wireline that can be directly placed in the wellbore via a block and tackle assembly 125 of the rig. At a lower end of the wireline 130 , in the non-vertical section 110 of the wellbore is a tool 135 . Like those described herein, the tool is designed to be located via the wireline at a predetermined location in the wellbore and then fixed to the wall of the wellbore by remotely actuating a slip and cone assembly (not shown) built onto the tool. In one instance, the downhole tool is a plug with a central bore that can be temporarily blocked in a single direction during an operation. In a wireline installation, the plug is typically actuated or set using a setting tool 137 schematically shown at an upper end of the tool. The setting tool includes a charge or some chemical compound that creates a force used to cause one part of the tool to move in relation to another part, thereby setting the slip. The action is initiated from the surface of the well by a signal that travels down a conductor in the wireline 130 . Setting tools are readily available and one setting tool is a Baker E-4 wireline setting assembly sold by the Baker-Hughes Company of Houston, Tex. FIG. 2 is a section view of a tool 200 shown in a wellbore 100 prior to being set. For illustrative purposes, the setting tool and wireline string is not shown. The tool includes a first portion and a second portion that are designed to move axially relative to each other in order to compress portions of the tool and set the tool in the wellbore ( FIG. 3 ). The main components of the tool are well known. For instance, there is a deformable sealing member 202 and a set of slips 205 that move across conical surfaces 207 to increase an outer diameter of the tool 200 and place the slips 205 , with their toothed outer surfaces, into contact with the walls of the cased wellbore 100 . FIG. 3 shows the tool set in the wellbore. Relative movement between the first portion of the tool and the second portion has caused the sealing member 202 and slips 205 to contact the wellbore 100 and fix the tool 200 in the wellbore. Visible in both FIGS. 2 and 3 is a bore 210 of the tool and a ball 215 that is seated in the bore to block the flow of fluid through the bore in at least one direction. Typically, the bore 210 is temporarily blocked to permit pressure to be developed above the tool in order to carry out an operation, like fracing the well. After the operation is complete, some tools are designed to be removed from the wellbore and reused. Others however, are designed to be milled and destroyed and are thus irretrievable. In one instance, the tools are constructed largely of a non-metallic material that can withstand certain extremes of temperatures and pH conditions and can be more easily drilled when the tool's use is completed. An example of such a non-metallic tool is disclosed and claimed in U.S. Pat. No. 6,712,153, assigned to Weatherford/Lamb, Inc. of Houston, Tex., and that patent is incorporated herein by reference in its entirety. FIGS. 2-7 all illustrate various aspects of the invention designed to facilitate the insertion of a tool 200 like the one shown, into a wellbore, especially a non-vertical wellbore. In the embodiment shown in FIGS. 2-4 , the tool is provided with a friction reducing system including friction reducing members in the form of rollers 300 that are outwardly extended and radially disposed around a front end of the tool 200 . The relationship of the rollers 300 to the body of the tool 200 and to the wellbore 100 therearound is illustrated in FIG. 4 . Visible is the body 301 of the tool, bore 210 of the tool and the rollers 300 that are mounted on axles 304 and operate to center the tool in the wellbore, provide a uniform annular space around the tool and prevent substantial contact between the body of the tool and the wellbore 100 . In FIG. 4 , the rollers 300 contact the wellbore casing 101 , leaving an annular space 302 between the body of the tool 200 and the casing wall. The advantage of this arrangement when a tool is run into a non-vertical wellbore on wireline is obvious. Rather than lay on the lowest side of the wellbore 100 , the tool 200 is held off the sides of the wellbore and only the rollers 300 with their friction reducing qualities are exposed to the wall. Additionally, because of the stand-off, the tool is less likely to be slowed by sediment and other debris that settles on the low side of the wellbore 100 . Finally, the uniform annular space 302 around the tool 200 improves its “pump down” characteristics. The position of the rollers 300 towards the leading end or front of the tool 200 increases their effectiveness. Rather than being installed on some other component, like the setting tool, the rollers are as close as possible to the leading edge of the tool that will be fixed in the wellbore. The rollers are also installed in a manner that ensures the outer diameter of the tool 200 will “draft” through the wellbore 100 . Alternatively, the rollers could be spring-mounted to permit some compliance but in all cases they are designed to maintain the tool coaxially in the wellbore. FIGS. 5 and 6 illustrate another embodiment of the invention that includes an additional feature also designed to facilitate the insertion of the tool into a wellbore. FIG. 5 shows another version of the tool 200 previously described with a wiper ring 400 installed around an outer perimeter of the tool 200 in a manner whereby the ring 400 extends into the annular space 302 between the tool 200 and the wellbore 100 . The purpose of the wiper ring 400 is to increase back pressure on and around the tool as fluid is pumped past it and used to urge the tool along the wellbore 100 . Also shown in FIG. 5 are flow ports 500 radially extending around the tool just behind the wiper ring 400 to direct a portion of the fluid from the annular space 302 to an area in front of the tool 200 . The redirection of some of the fluid helps wash debris from the front of the tool while permitting adequate fluid flow to act on the wiper ring 400 as discussed above. The wiper ring 400 increases that back pressure and its use with the centralizing rollers 300 is especially effective since the tool 200 is centered in a way that permits the wiper ring 400 to circumferentially extend into the annular space 302 around the tool rather than assuming an eccentric position due to the effect of gravity in a non-vertical wellbore. FIG. 7 uses arrows 600 to illustrate the flow of fluid through and around the tool 200 as it is urged along the wellbore 100 . The arrows show for example, that a certain portion of the fluid flow is directed to the wiper ring 400 and another portion flows into the ports 500 and out the front tool which includes a “mule shoe” shape 208 at its front end to avoid obstructions in the wellbore. The combination of the various optional features of the invention act together to increase the effectiveness of fluid pushed past the tool in order to urge it along a wellbore, especially a non-vertical wellbore. The system of the present invention is especially useful with tools made substantially of non-metallic material since these are typically lighter than metallic tools and have even less inclination to move in a non-vertical wellbore on their own. The parts of the system including the rollers, axles and the wiper ring are easily and typically made of non-metallic, drillable material and hence do not impede the milling and destruction of a non-metallic or composite bridge plug, like the one described in the ′153 patent incorporated previously herein. Additionally, the components can be made of material effective in uses in extreme pH conditions. As described and as shown in the FIGS., the present invention overcomes many problems associated with running tools into a non-vertical wellbore, especially on wireline or other non-rigid run-in strings. While the foregoing 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, and the scope thereof is determined by the claims that follow.

A system for facilitating the insertion of a tool into a wellbore, especially a non-vertical wellbore. In one embodiment a tool is fixable in a wellbore and includes centralizing, friction-reducing members that serve to keep the body of the tool off the walls of the wellbore. In another embodiment the tool includes a wiper ring that partially fills an annular area formed between the centered tool and the wellbore walls. The surface of the ring facing the upper end of the wellbore provides fluid resisting piston surface and permits the centered tool to be pumped down the wellbore more effectively.

[0001] This application is a continuation-in-part of provisional application 60/288,036, filed May 2, 2001, and incorporated by reference herein as if set forth in full. The present invention relates to absorbent products for use in hospital supplies such as mattress pads and medical dressings. A synthetic, non-woven fleece, initially designed for use in janitorial services, is highly flexible, low linting, solvent resistant, breathable, and sterile. It also has good physical integrity and ease of use. Further, it has a range of absorbency that is higher than materials in current use, without being so great as to encourage excessive fluid loss. These materials are also cost-effective. FIELD OF THE INVENTION BACKGROUND OF THE INVENTION [0002] Many different materials and structures have been suggested for wound dressings, but as a practical matter, the dressings that are most widely used in hospitals have remained substantially unchanged for at least about thirty years. Many of the improved dressings are elaborate and expensive to produce, and some rely on materials that are difficult to use. [0003] For example, U.S. Pat. No. 3,422,817 issued to Mishkin et al., Jan. 21, 1969 relates to a tracheotomy bandage that uses a resilient frame instead of adhesive to position the bandage. The patent is non-specific with respect to the absorbent materials that might be used. [0004] U.S. Pat. No. 5,939,339 issued to Delmore et al., Aug. 17, 1999 relates to a compression bandage that can utilize any known material as the absorbent layer, including foam, woven or nonwoven material including but not limited to rayon, polyester, polyurethane, polyolefin, cellulose, cellulose derivatives, cotton, orlon, nylon, or hydrogel polymeric materials as well as a nonwoven matrix plus a highly hydrophilic fluid absorbing material such as modified starches and high molecular weight acrylic polymers such as acrylonitrile fibers treated with alkali metal hydrides. This patent discloses that extremely absorbent materials are preferred. [0005] U.S. Pat. No. 3,858,585, issued to Chatterjee, January, 1975, relates to the use of absorbent fibers make of alkali metal salts of carboxyalkyl cellulose. These highly absorbant materials are swellable in water. This application relates to a cross-linking treatment for the fibers that reduces their solubility in water and the consequent tendency to yield a granular or gel-like mass. [0006] U.S. Pat. No. 5,941,840 issued Aug. 24, 1999 to Court, et al., relates to a multilayered wound dressing that includes a wound contact layer, an absorbent layer that can include viscose, polyester, and bi-component fiber structure with a gel-forming polymer that coats one side of the absorbent layer, and a hydrophobic layer. This structure is designed to maximize the liquid-absorbing properties of the gel-forming polymer. [0007] U.S. Pat. No. 6,075,177, issued to Bahia, et al., Jun. 13, 2000, relates to non-crosslinked carboxymethylcellulose filaments capable of absorbing at least 15 times their weight of saline solution, which retain enough fibrous character when wet to be removable as a coherent dressing from a wound, and discloses blending the carboxymethylcellulose fibers with up to 50% by weight of other fibers to strengthen the dressing. [0008] U.S. Pat. No. 5,830,496, issued to Freeman, Nov. 3, 1998 relates to a quilted multilayer laminate structure that can include a swellable material and yet remain dimensionally stable. [0009] U.S. Pat. No. 6,348,423, issued to Griffiths, et al., February 2002, relates to a wound dressing that includes an odor absorbent layer. The application discloses the use of any known absorbent fibers, and also discloses that highly absorbent fibers (at least 25 g/g) are preferred. [0010] U.S. Pat. No. 6,077,526, issued to Scully, et al., Jun. 20, 2000, relates to a wound dressing that uses a layer of graduated density felt to protect the wound from an absorbent layer make of highly absorbent fibers, to reduce the aggressiveness of absorption. [0011] U.S. Pat. No. 4,667,665, issued to Blanco et al., May 26, 1987 relates to a burn dressing that comprises a non-adherent polyethylene film exterior covering and an inner absorbent layer composed of five percent cellulose strata and a strata of non-woven polyester and rayon material. This dressing uses two separate fabrics for the absorbent layer, which must be purchased separately and then combined and formed together, thus adding manufacturing steps that are not needed if the present invention is used. [0012] U.S. Pat. No. 4,203,435 issued to Krull et al. May 20, 1980 relates to a multilayered dressing comprising at least 5 layers: two exterior layers of nonwoven fleece with low wound adherence, two absorbent layers containing cellulose fibers and synthetic fibers, and a distribution layer, such as tissue paper, between the absorbent layers. One of the disclosed absorbent layers is said to be 80% viscose and 20% polyester. Once the several layers are assembled, the entire dressing must be treated to reduce the presence of lint. SUMMARY OF THE INVENTION [0013] The present invention relates to the use of a material from an unexpected source as an absorbent in hospital dressings and supplies. More specifically, it relates to the use of a synthetic, nonwoven fleece as an absorbent layer is hospital dressings, wherein, the fleece is an 80-90% viscose, 10-20% polyester blend, having a fiber density of about 3-5 g/cm 2 and is available in various thicknesses and weights from Konus Konex d.o.o. Pe Netex, Konjice, Slovenia. [0014] In a preferred embodiment, the fleece is about 90% viscose (dtex 1,7—3.3/40-60 mm), and 10% polyester (dtex 1,7—3.3/40-60 mm), having an area weight of 180-200 g/m 2 and a thickness of about 2.0-2.2 mm. The fleece has a water absorbtion of greater than 1200 wt % as measured by DIN 53923, and a water absorbing speed of greater than 20 mm in 10 seconds, greater than 30 mm in 30 seconds, greater than 40 mm in 60 seconds, and greater than 55 mm in 300 seconds as measured by DIN 53924. The fabric further has a tensile strength (L) if >100 N/5 cm, tensile strength (T) >150 N/5 cm, elongation (L) <70%, elongation (T) <60%, all measured according to DIN 53857. Its schopper abrasion resistance is max. 15 g/m 2 according to DIN 53863. [0015] In another preferred embodiment, the fleece is about 90% viscose (dtex 1,7—3.3/40-60 mm), and 10% polyester (dtex 1.7—3.3/40-60 mm) bicomponent fiber where the bicomponent fibers have a softening point of between 220-120° C., having an area weight of about 180-200 g/m 2 and a thickness of about 1.8-2.0 mm. The fleece has a water absorbtion of greater than 1000% as measured by DIN 53923, and a water absorbing speed of greater than 25 mm in 10 seconds,, >35 mm in 30 seconds, >45 mm in 60s, and >70 mm in 300s, all as measured by DIN 53924. The fabric further has a tensile strength (L) of >150 N/5 cm, tensile strength (T) >150 N/5 cm, elongation (L) <70%, elongation (T) <60%, all measured according to DIN 53857. Its schopper abrasion resistance is max. 20 g/m 2 according to DIN 53863. [0016] In each case, the fabric is highly flexible, low linting, solvent resistent, breathable and sterile, as well as being cost effective. The fabric has an absorbance range on the order of 10-15 grams per gram fabric that is greater than commonly used materials, but not so great as to encourage excess fluid loss from a wound. [0017] An advantage of the present invention is that the material is easy to use, and that it requires a minimum of post-treatment during final product assembly to reduce linting. Another advantage of the present invention is that it is more absorbent than the materials in common use, without causing excessive fluid loss or suffering from loss of physical integrity, or requiring the addition of further materials. Yet another advantage is that the invention is very cost effective. [0018] Embodiments of the present invention include the use of the presently described absorbent layer in mattress coverings and bed protectors, in burn dressings and rope dressings, gauze dressings, abdominal pads, rope dressings, laparotomy sponges, endoscopic bullet sponges, tracheotomy dressings and gastrointestinal dressings. [0019] A specific embodiment of this invention would be the use of the absorbent layer in mattress coverings, particularly air mattress coverings for burn victims. Such burns frequently have a large amount of exudate, and in addition are often covered with copious amounts medicinal gel. It is desirable to have an absorbent protective cover for surfaces that will contact the patient, but such covers should not be too aggressively absorbent. In some cases, it is sometimes preferable to also include a covering that allows fluids to penetrate and yet remains dry to the touch. Such covering layers are known and available, for example, under the Goretex and Telfa trademarks, and are available from a number of sources, including KCI, San Antonio, Tex. In other cases, the additional covering layer may not be preferred. For example, in a particularly preferred embodiment, a bed specifically designed for burn patients has moveable arm supports clamped to the bed frame. The bed also has significant electronic components that can be damaged by fluids. The paddle-like supports are concave, and preferably have a disposable absorbent contoured cover including the present invention for catching exudate and medicinal gels from the patient's arms. [0020] In another embodiment, the absorbent layer is either constructed so it has a side that is not permeable to water, or is adhered to a material that is not permeable to water, such as a film, and may be covered with a water-permeable layer, to make a bed protector. Again, the product may include a skin contact layer that is permeable, dry-to-the-touch, and/or nonadherent to wounds, as desired for particular applications. [0021] In another embodiment, the absorbent layer can be used in a rope roll dressing, such as a tracheotomy dressing or a sacral decubitus dressing, used for packing heel ulcers for diabetic patients. The rope roll dressing can be made from narrow strips of the present invention. In addition, the web of the present invention can be made to have a greater thickness, but the same fiber density, to produce a dressing with a larger cross-section. Where a degree of wound debridement is considered desirable, the rope roll dressing may be made of the present invention only, or covered with an adherent gauze. Where a non-adherent dressing is desired a non-adherent gauze or covering layer can be added. [0022] In yet another embodiment, a burn dressing may comprise a non-adherent film or a gauze exterior covering and an inner absorbent layer of the present invention. [0023] In a further embodiment, a tube dressing, comprising a small square of fleece with a cut from the perimeter to about the center can be made using the present invention. For example a 5×5 cm square of fleece can be cut to fit a gastrointestinal or tracheotomy tube. DETAILED DESCRIPTION OF THE INVENTION [0024] The absorbent layer of the present invention is a fleece made of a blend of about 80-95% viscose and about 20-5% polyester. In a preferred embodiment, the blend is about 90% viscose and 10% polyester; in another preferred embodiment, the blend is about 90% viscose and 10% bicomponent fiber blend that can be polyester or another bicomponent blend such as polyethylene/ethylvinyl acetate having a softening point between 110 and 120° C. Examples of suitable fleeces are available as UNI MED 200 and UNI MED C 200, from Konus Konex, Slovenia. [0025] A dry laid, nonwoven web is produced using principles and machinery known to the textile or pulp fiber handling industry. First, the fiber blend is selected and loose fibers are mixed so that they are fairly evenly distributed in a large container. Then the fibers are carded, that is, passed through a series of steel rollers covered with saw teeth so that the fibers are “combed” and generally aligned with one another. The carded fibers are condensed by passing the fibers through a pair of smooth rollers having a fixed gap, or nip. The resulting fiber layer is light, diffuse, and too fragile to be used as a fabric. [0026] Several carded fiber layers are arranged in combination to make multiple fiber layers, or plies, that are laid on top of one another in a Cross-Lapping process. The number of fiber layers, together with the needlepunching and other finishing steps, determines the thickness of the final product. In a preferred example, multiple layers are used, the Cross-Lapped layers are applied at a nominal 90° angle to the machine direction of the base web and the resulting angles at which the crosslapped layers are applied vary with the relative rates of the web advance and Cross-Lap machine speed. The Cross-Lapping process assures that the orientation of the fibers in the different fiber layers can be varied, so that parallel and cross-laid layers can be combined. The Cross-Lapping process improves final product strength, absorbancy and speed of absorbance. [0027] The various fiber layers of the web are then consolidated. In a preferred embodiment, the fibers are mechanically bonded in a needle-punch process. Barbed needles arranged on a plate or cylinder are pressed into the web from both sides, penetrate into the multilayered web and then recede, leaving the fibers entangled, and consolidating the web somewhat. This process improves the fabric strength, appearance and abrasion resistance and absorbance. The degree of fibrous entanglement is manipulated by varying the needle configuration, length, barb shape, and density of needle punches, which depends in part upon the web advance rate. In the preferred embodiments, the needle configuration is random, The needle type is G.B. 15×18×38×3 M222 G3017, and the number of needle punches per square meter from the top is 170-190, while the number of needle punches per square meter from the bottom is 88. The resulting web can be used directly for an absorbent layer in medical products, or may 5 be subjected to further finishing treatments. [0028] For example, the fleece may be point-bonded. In a preferred embodiment, the polyester portion of a preferred blend may be formed from a bicomponent binder fiber blend having a softening point of between 110 and 120° C. These fibers soften and may melt under appropriate treatment, such as when the web is passed through twin rollers and exposed to steam heat in the target temperature range of 110 and 120° C. in a calendering process. The result is a fleece that is slightly thinner than the web described immediately above, and has a lower total water absorbance, but a higher water absorbing speed. [0029] The (optionally) bonded web may be used directly in a product, or may be further processed in a variety of finishing steps. Mechanical finishing steps include calendaring, brushing, embossing, laminating, creping and crushing. [0030] Calendaring is a process where a web is passed through a series of heated or cold rollers. Different types and arrangements may be used for different effects, such as softening, imparting gloss, surface texture or affecting the hand (density or fullness to the touch) of a fabric. A calendaring process can be used bond the fabric, as described above, or add a coating. For example, one or both sides of the web may be treated with an acrylic or latex coating. This coating can, for example, serve as a moisture-retardant surface. The web can also be printed or dyed, or have an antimicrobial finish applied. Another layer of a different kind of material can added, such as a waterproof film. This is called lamination when the film is passed with the web between rollers that typically are heated and pressurized so that the film bonds to the web. [0031] Embossing is a process where the web is passed through the nip of pressurized or possibly heated rollers, one or both of which may have a patterned surface, in order to impart a desired texture to the surface of the web. Creping can be considered a variation on embossing, that is intended to change the elongation and flexibility of the web by enlarging the web surface area. Crushing is a similar process that introduces crimp, stretchability and drapeability as well as softness to the web. Brushing is a process where the web is passed under one or more rotating brushes to give special surface effects. Typically, the surface fibers are raised to yield a soft or fur-like hand to the web. Over-brushing can result in increased linting, and is therefore preferred only if it is controlled. [0032] Any of the mechanical finishing processes are easily compatible with medical end-uses, so long as they do not substantially add to lint formation or leachability of the end product. [0033] Chemical finishes may also be applied to nonwoven webs. These include bleaching, dyeing, printing, sizing, or the addition of finishes to impart special traits such as antimicrobial or fire-retardent properties. Bleaching and dyeing, if performed, are preferably handled at the fiber stage. For medical applications, it is preferable to begin with virgin fibers and avoid the addition of any chemicals that might contact or leach into a wound, and so chemical finishes for webs that are intended as absorbent layers that may contact a wound are preferably those approved for use in wound contact applications. [0034] Further, the various additives may be combined with the nonwoven web during manufacture, or applied to the finished fleece before or after its incorporation into a hospital product. Examples include but are not limited to antimicrobial gels, powders or liquids, pain relievers, odor absorbers and wound healing promoters. Specific examples include calcium alginate (to reduce bleeding time) Banzalkonium chloride and silver compounds (reduce infection), activated charcoal (reduces odor), lidocane hydrochloride (relieves pain), collagen alginate and Becalpermin (promote wound healing).

An absorbent fleece for use in hospital supplies, comprises a fiber blend of about 80-95% viscose and 10% polyester formed into a dry laid, nonwoven web, wherein the web consists of multiple, carded and cross-lapped layers that are consolidated using a needle-punch process, whereby the fleece has a water absorbtion of at least about 1,000 wt % and an absorbing speed of at least about 20 mm after 10 seconds.

This is a divisional of application Ser. No. 08/495,323 filed Jun. 27, 1995, now U.S. Pat. No. 5,685,937, which is a continuation of application Ser. No. 08/124,638 filed Sep. 22, 1993, now abandoned. BACKGROUND OF THE INVENTION This invention relates to caskets or coffins used to house the remains of once living organisms. More particularly, this invention is directed toward a lightweight yet structurally strong casket highly suitable for cremation-type and interment ceremonies. The casket exhibits excellent structural integrity while being highly flammable and minimally harmful to the environment. The riddance of the bodies of the deceased can be accomplished in several ways, including burial and cremation. Because of the growing concern for the world's environment, both of these methods have been highly scrutinized. Environmental problems include the overpopulation of cemeteries and the effects of placing a corpse into the ground. In addition, environmental concerns arise from cremation, which is done in part to alleviate the concerns regarding burial, wherein harmful volatile organic compounds (VOC's) are released to the atmosphere via the burning of environmentally unsafe materials which are often used to manufacture caskets or coffins. In response to the environmental concerns surrounding cremation and in response also to the ever-rising costs of coffins and/or caskets for burial, inexpensive, lightweight and environmentally safe caskets have been developed. Most of these caskets are constructed from corrugated cardboard or the like. Corrugated cardboard tends to absorb moisture and degrades structurally when it is exposed thereto. However, because of the inadequate structural integrity of corrugated cardboard caskets, such caskets tend to twist and bend thereby threatening the security of the corpse therein and risking the stability of the miental health of friends and relatives who may unwantinigly witness an unscheduled viewing of the deceased should the casket fail. In the prior art, for example, the patent to Elder, U.S. Pat. No. 4,967,455 discloses a cardboard casket and a method of manufacturing the same. The patent discloses a corrugated cardboard casket constructed from multiple blanks of cardboard which are attached and folded to create the enclosure which forms the casket. However, as can be seen from the drawing and the text, only the use of corrugated cardboard is disclosed. Corrugated cardboard, which is currently and predominantly used in making lightweight caskets, inherently lacks structural integrity and, therefore, causes things made from it to also lack structural integrity. Therefore, the casket in Elder poses the risk of structural failure. For the morbid partygoer, U.S. Pat. No. 4,891,869 to Nutting, discloses a cardboard coffin for use at parties or similar occasions which is formed from a plurality of corrugated cardboard blanks. Again, the coffin is constructed by folding the corrugated cardboard into the shape of the casket or coffin. As with Elder, the use of the corrugated cardboard fails to provide the coffin with the necessary strength and structural rigidity of a more expensive coffin constructed from stronger materials. While the foregoing patents disclose the use of cardboard for constructing a more economical and environmentally safe casket, none of the prior patents discloses the use of polymer coated cellulose fiber (PCCF) or other material arranged in an open cell pattern or other patterns exhibiting similar high strength when constructed in accordance with this invention. SUMMARY OF THE INVENTION The invention disclosed herein is directed toward an economical and environmentally safe casket having excellent structural integrity for maintaining the shape of the casket and for exhibiting low torsional displacement during the carrying of the deceased. These properties are exhibited even when the casket is exposed to a high moisture environment. In accordance with the invention, the lightweight casket comprises a body containment compartment and a lid constructed from a core section of polymer coated cellulose fiber (PCCF) arranged in an open cell pattern. The core section for both the lid and for the body containment portion is comprised of a first and a second surface, wherein each surface is attached to a stabilizing surface element thereby causing a sandwich-type effect. Additionally, the core of this sandwich could be made of a solid surface structural material such as polystyrene foam. The core section may be comprised of a plurality of honeycomb cells wherein each cell is substantially a cylindrically shaped tube. The stabilizing surface elements are surface-treated planar sheets glued or otherwise attached to the open cell patterned core of PCCF. The combination of the open cell pattern core and the sandwiching effect via the stabilizing surface elements, supplies the structural rigidity of the casket. The core material provides the shear force for carrying the sandwich construction while the stabilizing surface elements carry the bending forces of the sandwich. The core material having the open cells perpendicular to the stabilizing surface elements exhibit a much stronger and stiffer structural shear carrying member than a longitudinally aligned corrugated configuration. This invention also includes the method of constructing the lightweight casket. The open cell patterned core section is first cut into a rectangular pattern suitable in size for folding into the body containment section. A first stabilizing surface element is attached to the underside of the core section, and a second stabilizing surface element comprising a plurality of sections is similarly attached to the upper portion of the core section but arranged in a pattern allowing the folding of the core section into the body containment section. During bonding of the stabilizing surface elements thereto the core acts as a pressure transfer mechanism to assure proper bonding. Upon folding, the walls and bottom of the body containment section are established and are adhered to each other for maintaining the enclosure-type structure. Finally, a lid is formed in a similar manner from a core section and stabilizing surface elements which are caused to form a dome-like shape via use of a jig and the application of air pressure. The casket disclosed is lightweight yet structurally rigid for supporting and carrying the contents placed therein. By using PCCF in lieu of more expensive materials, economic and environmental concerns are precluded while a very strong lightweight structure is established via the use of the open cell pattern and stabilizing surface elements. BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of illustrating the invention, there is shown in the accompanying drawings one form which is presently preferred; it being understood that the invention is not intended to be limited to the precise arrangements and instrumentalities shown. FIG. 1 is a perspective view of a lightweight casket constructed in accordance with the principles of the present invention; FIG. 2 is a partial cross sectional view taken along line 2 of FIG. 1; FIG. 3a discloses the use of a polystyrene based, solid surface, core in lieu of the honeycomb, open cell structure, core; FIG. 3 is a perspective view of the honeycomb core and first stabilizing surface element; FIG. 4 is a perspective view of the honeycomb core attached to the first and second stabilizing surface elements; FIG. 5 is a view similar to FIG. 4 with the addition of a second layer of core section attached to the inner bottom surface of the casket; FIG. 6 Is a perspective view of the lightweight casket during the folding stage; FIG. 7 is a perspective exploded view of the casket showing the insertion of the end inserts; FIG. 8 is a perspective view of the body containment portion of the casket prior to the addition of aesthetic features; FIG. 9 is a cross sectional view taken along line 9--9 of FIG. 8; FIG. 10 is an exploded view of the method of construction of the casket lid using a jig; FIG. 11 is a perspective view of the casket lid and jig with the jig cover in the open position; FIG. 12 is a perspective view of the jig cover and air pressure connector, and FIG. 13 is a cross-sectional view taken along line 13--13 of FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail wherein like reference numerals have been used throughout the various figures to designate like elements, there is shown in FIG. 1 a perspective view of the lightweight casket constructed in accordance with the principles of the present invention and designated generally as 10. The casket 10 is comprised essentially of the body containment portion 12 and the lid section 14. As shown in FIG. 2 for the body containment portion, it is comprised largely of the open cell core section 16, preferably a honeycomb pattern, being sandwiched between a first stabilizing surface element 18 and a second stabilizing surface element 20, both of which are formed from a fluid resistant material. The lid 14 is constructed in a similarly layered manner. The formation of the body containment portion 12 is accomplished in part as shown in FIG. 3. The honeycomb core 16 is cut to a substantially rectangular shape and of a size adapted to be folded into the casket. In forming the body containment portion 12, the first stabilizing surface element 18 is placed underneath the honeycomb core 16, while the second stabilizing surface element 20 is placed on top of the honeycomb core 16, as shown in FIG. 4. The first stabilizing surface element 18 is substantially rectangular in shape and scored with fold lines, as shown in FIG. 3, as well as being cut in four places 24a through 24d. The first stabilizing surface element 18, as shown, is larger in length than the core section 16. The fold lines and the cuts 24a through 24d function to facilitate the folding of the honeycomb core with the stabilizing surface elements attached thereto into the enclosure as shown in FIGS. 6, 7 and 8. The fold lines are not shown but are merely continuations of the cuts 24a through 24d as well as being perpendicular to those cuts adjacent the edge of the core section 16. The honeycomb core 16 is preferably formed from polymer coated cellulose fiber (PCCF) sheets but environmentally safe plastic or the like will also suffice. The core is comprised of a plurality of longitudinally extending cylindrically shaped cells interconnected and forming a honeycomb pattern. Because of their cylindrical shape, the members have strong structural rigidity along their longitudinal axes. With the first stabilizing surface element 18 being scored and cut for folding, the honeycomb core 16 is adhered to the upper surface thereof utilizing any suitable adhesive. In addition, an aesthetically pleasing material 26 is adhered to the underside of the first stabilizing surface element 18 for incorporating a pleasing texture and appearance to the casket. The second stabilizing surface element 20 is similarly adhered to the honeycomb core. However, the stabilizing surface element 20 is comprised of a plurality of separate sections 28a through 28c. The sections 28a through 28c comprise three rectangularly-shaped planer sheets which are arranged upon the honeycomb core as shown in FIG. 4. As can be seen, the separate sections are of sizes which allow spaces between the sections leaving rectangular portions 30a and 30b of exposed honeycomb. In a second embodiment, these spaces of core material left between the stabilizing elements may be cut on a forty five degree angle from the stabilizing element edges to the middle of the space. These angled cuts help to facilitate the folding of the core material and stabilizing elements into the body containment section. In a third embodiment, the core material between the stabilizing elements is removed and inserts are placed in the spaces for additional support. The purpose of the sandwiching effect of the honeycomb core between the two stabilizing sections is to provide the honeycomb core with structural rigidity by maintaining the cells of the core in a substantially perpendicular orientation to applied forces. The core acts as a pressure transfer mechanism and transfers the load to the outer stabilizing surface element 18 when a force is applied thereto. By leaving uncovered the exposed honeycomb core sections 30a and 30b, as provided for by the separate sections, the exposed honeycomb lacks the structural rigidity of the sandwiched honeycomb core. These exposed and, therefore, weaker sections of honeycomb inherently create fold lines on the core surface. In addition to the core 16, an additional layer 32 of core, as shown in FIG. 5, is glued to the structure over the center portion 28b of the second stabilizing surface element 20. The additional core 32 is of substantially the same size as the center portion 28b and in addition has a third stabilizing surface element 34 glued to the top thereof. The additional honeycomb core and stabilizing surface further strengthens and increases the structural rigidity of the casket bottom and provides extra structural security. Referring now to FIGS. 5 and 6, the lightweight casket is now ready for formation into the body containment portion 12. To initiate this process, the sides of the casket 36a and 36b are folded upward along the fold lines (not shown), cut lines 24a through 24d and the rectangular and exposed honeycomb sections 30a and 30b. By following this procedure, the formation shown in FIG. 6 is the result. Upon folding the sides 36a and 36b, the corners 38a through 38d must be folded inward towards the center of the body containment portion 12. As shown in FIG. 6, the corners 38a through 38d become part of the ends of the body container portion 12. However, the ends are further completed by folding upward the end extensions 40a and 40b toward the folded corners 38a through 38d. Before folding the extensions 40a and 40b, adhesive is applied on the contact surfaces thereof for adherence to the outside surfaces of the folded corners 38a through 38d. This provides a double shear path and increases the strength of the enclosure. Referring now to FIG. 7, the body containment portion is ready for insert of the end inserts 42a and 42b. Each end insert is comprised of the rectangular portion of honeycomb material having a stabilizing surface element 44 adhered thereto. The stabilizing surface elements 44a and 44b are adhered to the surface of the end inserts 42a and 42b facing the inner portion of the body containment portion 12 wherein the end extensions 40a and 40b act as the other stabilizers for the inserts 42a and 42b, respectively. Accordingly, the end inserts are inserted adjacent each end of the body containment portion. The side of each end insert having no stabilizing surface element adhered thereto is placed adjacent and adhered to the inner surfaces of the folded corners 38a through 38d, the end insert 42a being adhered to folded corners 38a and 38d, and end insert 42b being adhered to folded corners 38b and 38c. At this point in the construction process, the lightweight casket resembles the configuration shown in FIG. 8 wherein the body containment portion 12 is fully constructed. The lid of the lightweight casket is fabricated as shown in FIGS. 10-13. Similar to the body containment portion, the lid 14 is formed by placing a lid core section comprised of a honeycomb portion 46 between two lid stabilizing surface elements 48a and 48b as shown in FIG. 10. Due to the curved shape of the lid, the construction of it requires a somewhat different process than the construction of the body containment portion 12. The preferred method of constructing the lid 14 is to construct a jig 50 having an outer portion resembling the shape of the lid 14. The jig 50 is used to construct the lid 14 in a step-like manner which includes the application of a pressure source 52. As shown in FIG. 10, the jig 50 has an outer section 51 which is substantially in the shape of the lid 14 shown in FIG. 1. To initiate the lid construction process, the first stabilizing surface element 48a is placed into the jig 50. As shown in FIG. 10, the first stabilizing surface element is constructed from one to three separate elements, a center element and two triangularly-shaped end elements. These elements are placed into jig 50. Each of the elements has an edge 54 formed into a rectangular shape and adapted to receive perimeter stabilizing bars 56a through 56d. The perimeter stabilizing bars 56a through 56d form the portion of the lid which contacts the body containment portion 12. It is important that the edges which contact the body containment portion 12 have structural rigidity as well as the lid itself. Therefore, the perimeter bars 56a through 56d are placed into the folded edges 54a-54d and secured therein by adhering the edges 54a-54d thereto. Referring still to FIG. 10, the honeycomb portion 46, similar to that used with the body containment portion, is now placed into the jig 50 and over the first stabilizing surface element 48a. Prior to the insert of the honeycomb 46, adhesive is spread over the first stabilizing surface element 48a for causing the honeycomb portion 46 to adhere thereto. The honeycomb portion 46 is a substantially rectangular piece of material which is cut to a size which conforms to the lid shape and still contacts the entire surface of the entire first stabilizing surface element. It is not necessary to cut or provide fold lines in the honeycomb portion 46 in any manner due to the flexibility of the same in conforming to the general shape of the lid 14. With the honeycomb portion 46 inserted therein, the second stabilizing surface element 48b is placed over the top of the inserted honeycomb portion 46. The second stabilizing surface element 48b is rectangular but is comprised of an odd shaped section 58 having triangularly shaped but integral end sections 59a and 59b and having angular fold cuts as shown in FIG. 10. These sections 58 and 59a and 59b are placed on the honeycomb portion 46 as shown in FIG. 11 and conform to the jig 50. Prior to placement onto the honeycomb portion 46, adhesive is applied to the side of the sections which will contact the honeycomb portion 46. With all the elements in place, a pressure source 52 is applied to the integrated sections. As shown in FIGS. 11 and 12, a flexible cover 60 is hinged to and extends from the edges of the jig 50 via a hinged door 61 and is placed over the integrated elements just discussed, forming an air tight seal. The pressure source connector 62 extends from the flexible portion 60 so as to connect the pressure source 52 thereto. Accordingly, the pressure source 52 is connected to the connector 62 and pressure is applied to the lid 16. The pressure thereby forces the integrated sections together for adhering those which are contacting each other and forcing them into the shape of the jig 50. In addition, an aesthetically pleasing layer 64 is applied to the lid 16 for matching the body containment portion 12. When the air is removed and the sections are adhered together, the jig is disassembled and the lid can be removed, resembling the configuration shown in FIG. 1. The lid can also be formed in separate halves which is desirable for viewing purposes. The formation of the lid into two separate halves is performed essentially the same as just described except that each half is constructed separately in the jig such that finished edges are formed all around. For both the body containment portion 12 and the lid 14, materials and patterns other than PCCF arranged in a honeycomb pattern can be used. As shown in FIG. 3a, for example, an environmentally safe polystyrene-type material 65 can be used in lieu of the honeycomb material where it is placed between two stabilizing surface elements. Polystyrene foam placed between similar stabilizing surface elements exhibits substantially the same structural rigidity as the honeycomb portions and can be used interchangeably. Additionally, PCCF and other materials can be formed into truss patterns which also exhibit high structural rigidity when sandwiched between the stabilizing surface elements. Upon completion of the body containment portion 12 and the lid 14 as substantially described, the lightweight casket is finished by attaching ornamental elements thereto which gives the casket a richer appearance. As shown in FIG. 1, preformed corner pieces 66a through 66d are placed onto the corners of the lightweight casket 10. In addition to appearance, the corners 66a-66d provide extra strength in the body containment portion 12. The corners 66a through 66d are comprised substantially of two triangularly-shaped elements attached perpendicularly to each other. The corners are covered with the same aesthetically pleasing material as the rest of the lightweight casket exhibits. The corners 66a through 66d are simply glued to the body containment compartment corners as shown in FIG. 1. In addition to the corners, handles 68 are securely attached to each side of the lightweight casket for the carrying of the same. The inner portion of the lightweight casket in its finished condition is also designed in an aesthetically pleasing manner having linings and pillows. The lightweight casket is used in a manner similar to any other casket. Because of the structural rigidity providing by the sandwiching of either the open cell or solid surface core materials, there are no special precautions which must be considered in handling the lightweight casket 10. The body is simply placed in the casket as with any other casket and it can be carried similar to any other casket. For cremation purposes, the casket is highly flammable and, as discussed, is not harmful to the environment and can simply be placed into the furnace without alteration. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and accordingly reference should be made to the appended claims rather than to the foregoing specification as indicating the scope of the invention.

A lightweight structurally sound casket formed preferably of a sandwich construction using a core of an open cell or honeycomb patterned material and fluid resistant surface elements. The casket is comprised of a body containment portion and a lid portion, each of which has the sandwich construction as the main structural element. The open cell material is structurally enhanced by being sandwiched between first and second stabilizing surface elements in both the body containment portion and the lid portion. In addition to the stabilizing surface elements, an aesthetically pleasing material is adhered to the outer portions of the body containment section and lid so that the casket has an attractive appearance. The body containment portion is constructed from rectangular pieces of the open cell material and stabilizing surface elements by folding the same into a box-like configuration. The lid portion is formed from placing the open cell material and the stabilizing surface elements into a jig, applying adhesive between the elements and finally, applying pressure thereto for adhering the elements together. As a final touch to the casket, ornamental features such as corner pieces and handles are added to the casket for aesthetic effects. The casket is environmentally safe for cremation and interment ceremonies and is economic and lightweight.

This is a division of co-pending application Ser. No. 727,589 filed on Apr. 26, 1985, now abandoned. BACKGROUND OF THE INVENTION This invention deals with a hold down device for multiple layered roofs, a device for detecting leaks in a roof, and a method of detecting leaks in a roof. More specifically, there is provided a means for holding a multiple layered roof in a secure manner, with the additional benefit that the hold down devices utilized for such a purpose are adapted to function as water leak detectors. Large industrial and commercial buildings quite typically have flat or near flat roof surfaces. These roof surfaces generally are multi-layered, that is they generally have in combination a roof supporting structure which is surmounted by a deck, and various layers of water impermeable membranes, thermal insulation and a ballast layer to assist in holding the entire roof from being blown away. These types of roofs tend to be economical and function quite well as long as there is no break in the water-impermeable membrane. Once the water-impermeable membrane is broken, water enters the roof deck and seeps and runs and eventually enters the interior of the building. When this happens, the roof must be repaired, but often one cannot detect where the membrane is broken and hence cannot effectively undertake repairs. A second problem with the multiple layered roof is the inability of modern science to devise a scheme for holding the roofs in place, especially during violent storms accompanied by high winds. Current acceptable methods for holding down roofs are to cover the multiple layers with gravel or stone, point attachment, or a combination of both. This obviously tends to hold the roof down but such ballast contributes to the weight of the roof and requires strong structural support which results in higher costs for installation of such a roof. It would be desirable to have a system for holding down roofs that would have the benefit of lowering the costs of the installation of such roofs. It would be a further benefit if the system used to hold down the roof could act as a more or less permanent system to detect leaks in the roof. Several systems are currently in use for detecting leaks in a roof, for example, Gustafson, in U.S. Pat. No. 3,824,460, issued July 16, 1974, discloses a leakage sensor strip which is a pair of encased wires held essentially parallel to each other by a plurality of spaced webs which are an extension of the casing of the wires. The sensor strip is placed and held flat on a floor or roof deck over a certain length so that leakage anywhere along the probe will result in a capacitance change which can be sensed. It is important to note that this system does not provide a hold down function and furthermore, this sensor strip requires a metal channel over its full length in order to hold it flat on the surface. This feature renders the method of installing very expensive and time consuming. Another patent, U.S. Pat. No. 3,967,197, discloses a method of detecting moisture in a multilayered roof system. The method disclosed consists of reading the capacitance at various predetermined points on a roof surface to create a base line reading and then periodically re-reading the capacitance at these same points to determine a deviation from the original reading. A capacitance meter is moved over the surface of the roof. Wherever the moisture in the roof has increased, the dielectric constant increases and the expectation is that this is indicative of a water leak. A third system that has been used for detecting water leaks in a roof is that disclosed in U.S. Pat. No. 4,110,945, issued Sept. 5, 1978. In that method, a plurality of water detectors are positioned under the water-impermeable membrane of a roof. In the event that the water-impermeable membrane is broken and the roof leaks, the general area of the leak can be determined. Each such water detector is electrically powered and connected to a sensor at a location remote from the roof. It should be noted that there is no hold down function in either the latter two systems and further, it should be noted that if the system of U.S. Pat. No. 4,110,945 requires repair, it may be required to remove and replace a fair section of the roof. In spite of the usefulness of the above noted systems, there is still a need for a device for conveniently holding down roofs, and a need for a simpler, more dependable means of detecting roof leaks. SUMMARY OF THE INVENTION The present invention deals with solutions to the problems of securing a roof in place and the inability to quickly and accurately determine the location of roof leaks. The instant invention therefore comprises a hold down device, a modified hold down device for use in detecting water leaks in a roof, and a method of securing a roof in place as well as a method for detecting leaks in a roof. Thus, the present invention deals with a hold down device consisting of two joinable pieces. The device is designed such that the bottom half of the device is securely attached to a roof deck over the water-impermeable membrane and after the multiple layers of the roof are installed, the top half of the device is operably joined with the bottom half and tightened down such that the top plate of the top half compresses the top layer of the multiple layer roof and holds the top layer and all intervening layers to the roof deck. The result is a novel hold down device which has penetrated through but has not destroyed the water-impermeable membrane and has provided secure anchoring for the roof layers. This device can be modified in order to enable the easy detection of roof leaks. This is accomplished by providing electrical leads in the bottom plate where it is anchored to the roof deck. The leads pierce the water-impermeable membrane and enter the roof deck but the bottom plate is compressed over the penetrations made by the leads and acts as a seal on the penetrations when the plate is securely fastened to the roof deck. The electrical leads are continued through the internal stems of the device and terminate in electrical contact points. The top half of the device is similarly constructed so that the two halves, when joined, provide electrical contact points at the upper surface of the roof that can be used to ascertain water leakage in the roof. When such devices are used in combination to secure a roof, they provide a regularly spaced layout of such devices that one can use to determine the exact location of a water leak in the roof. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectioned view of the hold down device which is a vertical section at the center point of the device. FIG. 2 is a schematic sectional view of a portion of a roof showing the placement of some devices of this invention. FIG. 3 is a top view of a roof showing the regular placement of the devices to hold down the roof. FIG. 4 is a side plan view of one version of an alternate adjusting and locking mechanism for the device (upper piece). FIG. 5 is a top plan view of the device of FIG. 4. FIG. 6 is a side plan view of one version of an alternate adjusting and locking mechanism for the device (lower piece). FIG. 7 is a bottom plan view of the device of FIG. 6. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in which like-numbers indicate like-parts or pieces, there is shown in FIG. 1 a hold down device of this invention which is comprised of an enlarged flanged base 1 and a hollow, first adjustable nesting stem 2 which is shown herein as being threaded. The flange is essentially flat on the bottom 3 which rests on the water-impermeable membrane 4 which in turn covers the roof deck 5 in a roof structure. The flat flange contains two aperatures 6 which are receptacles for electrical leads 7, the leads 7 are designed so that they are detachedly secured in the aperatures 6 and such that they extend through the aperatures 6 and pierce the water-impermeable-membrane 4 and the roof deck 5, when the device is in place. The flange 1, which can be fabricated from metals, metal alloys or plastics, has a small center bore 8 through which passes a mechanical fastener 9, the fastener being the principle means by which the device is secured to the roof deck 5. Many types of conventional fasteners can be used. As can be noted from FIG. 1, the enlarged flanged base is integrally surmounted by a hub 10 which is internally threaded to receive the hollow, threaded, first nesting stem 2. This hollow nesting stem contains an inner wall 11 which restrains electrical conduits 12 when they are used in the device. The inner wall 11 can be fashioned from plastic or cardboard or any lightweight material as its only function is to restrain the electrical conduits 12. The uppermost edge 13 of the first nesting stem 2 is surmounted by an electrical insulating layer 14 of an electrical insulating material. The electrical insulated layer 14 is surmounted by at least two metal electrical, semi-circular contacts 15 and each such contact has attached to it an electrical conduit 12, which it will be noted furnishes an electrical connection between the metal leads 7 and the metal contacts 15, the electrical conduits 12 beginning at the electrical leads 7, ascending through the hollow of the first nesting stem 2 and terminating at the metal contacts 15. A second, hollow nesting stem 16 is operably associated with the first nesting stem, in this case by mating threads. The second nesting stem 16 is integrally surmounted by an enlarged flanged top 17, comprising a top plate 18 having a centrally located bore 19 and two aperatures 10 therethrough. The top plate 18 has a centrally located hub 21 which has a center bore therethrough to receive and detachedly secure the second nesting stem 16. The top plate 18 contains in its center bore, a removable tightening plug 22 which has a protrusion 23 extending above the top plate 18 in order that the device can be adjusted up or down by turning the plug 22. The two aperatures 20 have electrical leads 24 removably inserted in them. A compression spring 25 is removably mounted on the plug 22 at the bottom of the plug at(A). The compression spring 25 extends through the hollow to the end of the second nesting stem 16. The end of the compression spring 25 that is distal from its attachment to the plug 22, has an insulating layer 26 of an electrical insulating material attached to the edge 27 thereof. Surmounted on the layer 26, are at least two metal point contacts 28. Attached to each metal point contact 28 is an electrical conduit 29, the electrical conduits 29 ascending through the hollow of the second nesting stem 16 and passing through aperatures 30 and each connecting to and terminating at the electrical leads 24. When the first nesting stem 2 and the second nesting stem 16 are joined, the second nesting stem 2 is turned down on the first nesting stem 16 and the metal contacts 15 intimately touch metal contacts 28 thus completing the conduit from metal leads 7 to metal leads 24. The compression spring 25 ensures that this contact is maintained. In use, a roof structure is provided with a roof deck and a water impermeable membrane is laid down over the roof deck. The roof deck and membrane can be premeasured and premarked for installation points at which the devices of this invention are secured but it is normal practice to install the roof piecemeal after the water-impermeable membrane is laid down and therefore, the size of the thermal insulation planking or the size of planking on the top most layer can determine the installation points of the device since the device is designed to be installed where the four corners of the top planks intersect so that the top plate 18 of the device can grip the corners of the top most planks and hold them down or, the devices can be installed such that the device holds down the center of the top planks. By whatever procedure desired, the enlarged flange base 1 containing the first nesting stem 2 and the hub 10 integrally secured thereto, is first securely fastened to the roof deck, over top the water-impermeable membrane, using a mechanical fastener such as a bolt, screw or nail inserted through the center bore 8. During this installation, the metal leads 7 pierce the water-impermeable membrane but as soon as the mechanical fastener draws the enlarged flange base tightly to the roof deck, the penetrations made by the leads are sealed by the flange and the water-impermeable membrane remains intact. Next, the roof is installed except for the ballast layer and as the top planking of the roof is installed, the top half of each device is engaged with the bottom half of each device and the top half is turned down until the top plank of the roof is securely fastened. In the process of turning the top half of the device down, it will be remembered that the metal contacts of the two pieces contact each other. As the top half of the device is turned down to secure the top planks, the compression spring is compressed in the hollow of the second nesting stem, thereby not requiring any further adjustments in the device to ensure that the contacts are meeting. Finally, the ballast layer is applied to the roof. Rigid thermal planks are often the final layer. Obviously, the flanges and stems which make up this device, and which contain the electrical accoutrements, are easiest prepared in the workshop prior to their use on the roof, although it is possible to prepare them on the job site if it is required. When prepared in the workshop, the flanges and lower parts of the stems are dipped in a curable elastomeric compound to maintain them erosion and moisture free while in use. FIG. 2 shows schematically the typical placement of the devices in a roof system. The roof deck 5 is shown as the bottom most layer of the multi-layered roof. The roof deck 5 is topped by the water-impermeable membrane 4 and three devices labelled (B) are affixed over the water-impermeable membrane using a mechanical fastener 9. One device (c) is shown in phantom in the center of the thin concrete layer. A foamed thermal insulation layer 31 is then placed on top and the whole is surmounted by a light layer of ballast 32, such as crushed stone or thin concrete. If the device requires repair at any time, the ballast layer or thin concrete is removed only from the device to be repaired, the top half of the device is removed and the bottom half unsecured from the roof deck. The reverse order is used when replacing the device. As depicted in FIG. 3, there is shown a top view of a roof wherein the dots represent the devices of this invention. The roof is depicted without the ballast layer for purposes of explaining the method of the invention. Letters have been used along the vertical axis and number along the horizontal axis in order to more fully explain the method of this invention. The amorphous spot 33, in the middle of the diagram is intended to be water over a small break in the water-impermeable membrane which is not visible by a visual inspection of the roof surface. In order to detect this leak, one locates the devices of this invention and scrapes away the light ballast layer. The two metal leads on the surface of the device, say, for example, at point B4, are contacted by piercing the elastomeric coating over the metal lead with sharp metal probes which are attached to a sensor instrument. With each surface probe so located, readings of the dielectric constant are taken of the device, which in fact are readings of the two metal leads that form part of the flanged base and that have pierced the roof deck upon construction. Several readings taken at points B3, B4, B5, C4, C5 and C6 clearly indicate that there is water at B4 and C5 and none at B3, B5, C4 and C6, therefore indicating that the break in the membrane is in that nearby area. This area is then subjected to repair. The devices of this invention can be manufactured from metal, metal alloys or plastics. Preferred are lightweight, touch plastics since they can be filled to enhance their strength. Such plastics can be for example, olefinic polymers such as polyethylene and polypropylene; polyvinylchloride; urethanes and nylon. Preferred are nylons and most preferred are filled nylons. The drawings and examples herein show mated threads to couple the device together but it is contemplated within the scope of this invention that other means can be used to adjust and couple the two pieces of the device. For example, FIGS. 4 and 5 show a device which is useful herein for that purpose. Instead of threads, the first nesting stem 2 is composed of a stem whose surface is scrolled in regular layers so that there is formed compressable fins 34. The fins do not travel around the entire outer circumference of the stem but are interrupted at one or two places. The interuptions serve as smooth channels 35 for the movement of the teeth 36, shown in phantom on the interior surface of the second nesting stem 16, of FIG. 6. FIG. 5 is a top plan view of the bottom half of the device and shows the enlarged flanged base 1, containing aperatures 6 and 8; hub 10; smooth channel 35 and compressable fins 34. FIG. 6 shows the upper half of the device with the aperatures 20 and the plug 22 in place. Vertical rows of shark-line teeth 36 are performed in the interior wall of the hollow stem. FIG. 7 shows a bottom plan view of the top half of the device. Shown there is the bottom of the plug 22; the vertical rows of shark-like teeth 36; the aperatures 20 and the hub 21. In use, the stem of the top of the device is fitted to the stem of the bottom half of device such that the shark-like teeth 36 are not aligned with the smooth channels 35 and the top half is forced down onto the bottom half whereupon the shark-like teeth 36 lock into the fins 24 and the device cannot be separated because of the ratchet lock of the shark-like teeth 36 in the fins 34. To remove the top half of the device, the top half is forced down slightly, the top half turned until the shark-like teeth 36 match the smooth channels 35 and the top half is withdrawn as the teeth move easily up the smooth channel. The elastomeric material used to coat the ends of the device and prevent erosion can be any elastomeric material. Such materials are organic rubbers, silicone rubbers and silicone-modified organic rubbers.

A hold down device for multi-layered roofs. The hold down device can be modified to afford a water leak detector. A method of using the devices in securing a multi-layered roof is discussed.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 10/186,131 filed on Jun. 28, 2002. The disclosure of the above application is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates generally to flow nozzles, and more specifically to flow nozzles having an inner and an outer wall separated by interstitial flow spacing. BACKGROUND OF THE INVENTION [0003] Rocket engine nozzles are currently configured in two general shapes, conical and ramp configuration, both in various sizes and materials to suit the high temperature and pressure environment for which they are designed. A common design for conical shaped rocket nozzles provides a single pass, multiple brazed-tube nozzle wall. A plurality of tubes are joined side-to-side to form an outer wall of a nozzle wherein the tubes also act as flow channels for the combustion fuel. Combustion fuel enters each of the tubes from a manifold, is preheated as it traverses the tubes, and simultaneously acts to cool the nozzle. This conventional design includes a plurality of circular tubes numbering approximately 1,000 to approximately 1,100 tubes. The individual tubes are drawn and swaged such that a diameter of each tube decreases and its wall thickness increases from a nozzle discharge end to a nozzle inlet end. This conventional tube design includes materials that are difficult to weld, particularly in a tube-wall to tube-wall configuration. A brazing process is therefore used to join the tubes. Each of the drawn and swaged tubes is first coated with a nickel material which is suitable to braze the plurality of tubes in a side-to-side configuration. The swaged and coated tubes are arranged having the larger diameter ends adjacent to one another to form the nozzle conical shape and the arrangement is collectively furnace brazed. [0004] One drawback of brazed rocket nozzles is that repair of reusable nozzles is difficult and expensive. The heat of combustion as well as the number of cycles of heating and cooling that a reusable nozzle is subjected to cause the materials to fatigue and crack. Because the tube materials are difficult to weld, nozzle repair is generally limited to brazing techniques on each tube. Brazing of individual tubes is time consuming and often incapable of repairing large cracks. If a tube cannot be braze-repaired, the tube is sealed. When a specified percentage of tubes are sealed, the nozzle can no longer be used. [0005] A common rocket nozzle has a diameter of approximately 76.2 cm (30 in) adjacent to the main combustion chamber of the rocket engine. The large diameter or distal end of the nozzle has approximately a 183 cm (6 ft) diameter. A further drawback of the brazed nozzle design is that attempts to repair a nozzle of this size itself creates problems in that heat input during the repair process can create sequential problems with the brazed material in adjacent or local tubes. [0006] A further drawback of the common brazed nozzle design is that the brazed joint is the weakest link. Even a small rupture in a brazed tube-to-tube joint can result in either reduced cooling at the upper nozzle (i.e., adjacent to the combustion chamber) or a leak of preheated fuel into the nozzle flame, either of which can result in catastrophic nozzle failure. [0007] A need therefore exists for a nozzle design providing a repairable configuration which does not rely on the brazing process. A need also exists to replace the tube-to-tube design commonly used with a configuration which is easier to form and which permits either repair of individual flow channels or replacement of segments of flow channels. SUMMARY OF THE INVENTION [0008] According to a preferred embodiment of the present invention, a fluid flow nozzle is provided comprising a plurality of adjacent L-shaped channels. Each L-shaped channel includes a channel linking member and a channel radial member, said channel radial member being arranged approximately perpendicular to said channel linking member. Each channel linking member is joined to an adjacent L-shaped channel linking member forming a contiguous surface of linking members. A distal end of each channel linking member is weldably joined to its adjacent L-shaped channel at an intersection between its channel linking member and its channel radial member. The plurality of channel linking members thus joined form the contiguous surface having an inner face and an outer face. The plurality of L-shaped channels thus joined are then formed in a desired geometric shape having each of the channel radial members extending outwardly from a central axis point defining the geometric shape. Each channel radial member extends radially outward from the outer face of the contiguous surface. [0009] A jacket is circumferentially disposed about the contiguous wall in contact with a distal end of each of the channel radial members. A predetermined position of each channel radial member is mapped through the jacket wall. A weld joint is formed through the jacket wall along each intersection between a jacket inner wall to the distal end of each channel radial member. The weld joints are preferably laser welds made by a laser welding torch programmed to follow the predetermined position of each channel radial member. [0010] The plurality of channel linking members forms both a nozzle inside boundary and an inside surface for a plurality of flow channels each formed by adjacent pairs of the channel radial members. The jacket weldably joined to each of the channel radial members forms an outside surface of each of the plurality of flow channels. In a preferred embodiment, each channel radial member has a reduced wall thickness compared to both the channel linking members and the jacket. By reducing the wall thickness of each channel radial member, a pressure from a fluid flowing within the flow channels, upon reaching a critical pressure, will collapse one or more channel radial members before rupturing the pressure boundary formed by either the channel linking members or the jacket. This design choice results in containment of the fluid within the flow channels reducing the chance of combustible fluid escape to either the nozzle inside chamber or to the atmosphere outside of the jacket. [0011] In still another preferred embodiment of the present invention, the plurality of channel linking members form an outer surface of a nozzle and the jacket forms an inner surface of the nozzle. The plurality of channel linking members form a contiguous surface having an inner face and an outer face. The plurality of L-shaped channels thus joined are then formed in a desired geometric shape having each of the channel radial members extending inwardly from the contiguous surface inner face toward a central axis point defining the geometric shape. [0012] In a preferred embodiment of the present invention, each L-shaped channel is drawn and swaged such that a distal end of each channel linking member has a reduced wall thickness and an increased width relative to its proximate end. Each drawn and swaged L-shaped channel is placed in a preformed tool to control spacing between L-shaped channels and provide a desired geometric shape. The geometric shape of the preformed tool comprises preferably one of a circle, an oval, a cone, a cylinder, an ellipsoid, a paraboloid, and a hyperboloid. Each of the channel linking members are joined at their narrower proximate ends to form a first end of a nozzle assembly. Each of the channel linking members are similarly joined at their wider distal ends to form a second end of a nozzle assembly. A geometric shape approximating a cone is formed thereby. [0013] In another preferred embodiment, the nozzle assembly is preferably constructed in quarter or similar sub-unit sections. Each quarter section has an edge seam weldable to an adjacent quarter section edge seam. Assembly using quarter sections potentially improves the nozzle manufacturing time by permitting a non-repairable defect in one section of the nozzle to be removed and replaced quickly and easily. Later maintenance of the nozzle is also improved by allowing sections which have non-repairable cracks or leaks formed therein to be replaced in quarter sections, along edge seams. A non-repairable crack or rupture in any quarter section of the nozzle assembly will therefore not result in plugged flow channels or non-reusable nozzles. Quarter sections of different nozzle designs can be preassembled for either initial construction use or later maintenance replacement. [0014] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The features, functions, and advantages can be achieved independently in various embodiments of the present inventions or may be combined in yet other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS [0015] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: [0016] FIG. 1 is a perspective view of a circular assembly of L-shaped channels encompassed by a jacket in accordance with a preferred embodiment of the present invention; [0017] FIG. 2 is an exploded perspective view of Area 2 of FIG. 1 , showing the assembly of individual L-shaped channels and the jacket; [0018] FIG. 3 is an exploded top view of Area 3 of FIG. 2 showing the corner weld joint assembly of a preferred embodiment of the present invention; [0019] FIG. 4 is an exploded top view similar to FIG. 3 , showing an alternate embodiment of the present invention having beveled edges at distal ends of each of the channel linking members; [0020] FIG. 5 is a perspective view of a subassembly of channel linking members arranged into a cone shape prior to longitudinal laser welding of the channel linking members; [0021] FIG. 6 is the perspective view of FIG. 5 further including a jacket disposed approximately three quarters of the perimeter of the cone shaped nozzle of FIG. 5 to illustrate an edge seam of the present invention; [0022] FIG. 7 is a partial exploded view taken from FIG. 6 showing the external laser welds joining the jacket to each of the channel radial members and the longitudinal laser welds joining each of the channel linking members; [0023] FIG. 8 is the perspective view of FIG. 5 further showing exemplary flow channel flow patterns for a two pass flow channel embodiment of the present invention; [0024] FIG. 9 is a partial top section view taken from area 9 of FIG. 8 showing narrow radial spacing between channel radial members at an upper or narrow cone end of a nozzle assembly of the present invention; [0025] FIG. 10 is a partial top section view taken from area 10 of FIG. 8 showing wide radial spacing between channel radial members at a lower or wide conical end of a nozzle assembly of the present invention; [0026] FIG. 11 is a perspective view of a single L-channel of the present invention showing a swaged channel linking member having a reduced wall thickness and wider flange on a distal end compared to its proximate end; and [0027] FIG. 12 is a partial perspective view of a preferred embodiment of the present invention, having an inverted arrangement of the linking members and jacket. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0028] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. [0029] Referring to FIG. 1 , a cylindrical nozzle assembly 10 of a preferred embodiment of the present invention is shown. The nozzle assembly 10 comprises a plurality of L-shaped channels 12 each joined by a longitudinal weld joint 14 . A jacket 16 encloses the plurality of L-shaped channels having butted ends welded at an exemplary jacket edge seam 18 . [0030] Referring to FIG. 2 , an exploded view of the partial area 2 of FIG. 1 is shown. Each of the plurality of L-shaped channels 12 comprises a channel linking member 20 and a channel radial member 22 . The channel radial member 22 is arranged approximately perpendicular to the channel linking member 20 . Each of the L-shaped channels 12 are arranged such that each channel linking member 20 lies approximately perpendicular to a center of curvature A. A nozzle inner wall 23 is thereby formed about the center of curvature A along an assembly radius C. Each channel radial member 22 is centrally aligned approximately parallel with each of a plurality of radial lines B. [0031] A distal end of each channel linking member 20 forms a corner joint with an adjacent L-shaped channel at an outside facing corner between the channel linking member 20 and the channel radial member 22 . A longitudinal weld joint 14 is formed at each corner joint which will be described in further detail in FIG. 3 . The jacket 16 is disposed about the outer perimeter of the nozzle assembly 10 and is welded to a distal end of each channel radial member 22 at a plurality of exterior laser weld joints 26 . [0032] The nozzle inner wall 23 formed by the plurality of channel linking members 20 and the jacket 16 encloses a plurality of flow channels 24 . Each channel radial member 22 forms a boundary between adjacent flow channels 24 . Each flow channel 24 is sealed and separated from its adjacent flow channel by the plurality of longitudinal weld joints 14 and the plurality of exterior laser weld joints 26 . Each flow channel 24 permits a fluid flow in either direction as shown in FIG. 2 for a combustible fluid such as a rocket fuel. [0033] Referring now to FIG. 3 , an exemplary pair of L-shaped channels 12 are shown. A distal end of one channel linking member 20 identified as a butted end 28 is aligned with the adjacent L-shaped channel 12 prior to welding. A laser torch 30 having a laser beam 32 is used to form each of the longitudinal weld joints 14 (shown in FIG. 2 ) at the junction between the butted end 28 and the adjacent L-shaped channel 12 . In a preferred embodiment, no filler weld material is added to the longitudinal weld joints 14 . [0034] Each pair of L-shaped channels 12 is held in the general configuration shown in FIG. 3 prior to welding by one or more assembly tools (not shown) which are known in the art and will therefore not be further discussed herein. The assembly tool maintains fit-up between each pair of the L-shaped channels 12 . A radial member distal end 33 is also positioned by the assembly tool adjacent to the jacket 16 to maintain fit-up to weldably join the jacket 16 to each radial member distal end 33 using one of the plurality of exterior laser weld joints 26 shown in FIG. 2 . A laser torch 34 and its associated laser beam 36 are used to cut through the thickness of the jacket 16 to each radial member distal end 33 to join the jacket 16 to each radial member distal end 33 . Similar to the longitudinal weld joints 14 , no filler material is used to make the exterior laser weld joints 26 in the preferred embodiment shown. [0035] The longitudinal weld joints 14 formed at each butted end 28 of the channel linking members 20 are easily accessible for welding. The exterior laser weld joint 26 formed at the radial member distal end 33 to the jacket 16 requires indication of the location of each radial member distal end 33 prior to making the weld joint. The location of each radial member distal end 33 can be found in several ways. In one technique known in the art, an x-ray machine (not shown) is used to identify the location of each radial member distal end 33 through the thickness of the jacket 16 to ensure proper alignment for the exterior laser weld joint 26 . Similarly, an ultrasonic sensor (not shown), also known in the art, can also be used to identify the location of each radial member distal end 33 prior to making the exterior laser weld joint 26 through the jacket 16 . Fit-up between each radial member distal end 33 and the jacket 16 for making the exterior laser weld joint 26 is obtained through tooling (discussed above) which is known in the art. The tooling forces each channel radial member 22 into approximate contact with the jacket 16 to retain the minimal required clearances for welding fit-up. [0036] Referring now to FIG. 4 , an alternate embodiment of the present invention is shown. A beveled end 38 for each channel linking member 20 is formed. The beveled end 38 is known in the art, and is used if a filler material (not shown) is desired in forming the longitudinal weld joint 14 between each channel linking member 20 and its adjacent channel linking member 20 . A beveled end of the channel radial member 22 is undesirable because it would reduce the contact surface for the exterior laser weld joint 26 , and the use of a filler material adds unnecessary time and expense to the process of making these welds. Other joint designs known in the art can also be substituted. [0037] Referring to FIGS. 5, 6 and 7 , the assembly stages of a conical nozzle 40 are shown. The conical nozzle 40 is formed using a plurality of swaged L-channels 42 each having a radial member 44 . A swaged L-channel 42 is further detailed in FIG. 11 . The plurality of swaged L-channels 42 are arranged in a tool (not shown) to hold each of the swaged L-channels 42 prior to welding in a configuration of the conical nozzle 40 . An expansion tool (not shown) known in the art can also be used to force each of the swaged L-channels 42 into substantial contact with the tool. Each longitudinal weld 50 is made at this time to form the inside wall of the conical nozzle 40 . A conical jacket 46 is then disposed about each of the radial members 44 as shown in FIG. 6 . The closure for the conical jacket 46 is formed by at least one conical jacket edge seam 48 . In a preferred embodiment of the present invention, the conical nozzle 40 is formed in quarter sections, as indicated by arrows P in FIG. 6 , such that a quantity of 4 conical jacket edge seams 48 are used to join the assembly. By forming the conical nozzle 40 in quarter sections, stack-up tolerances as each of the swaged L-channels 42 are joined can be controlled and if a problem during manufacture of the conical nozzle 40 is encountered, a quarter section of the assembly can be removed and replaced. FIG. 7 also shows the exterior laser weld joints 52 which are formed similar to the exterior laser weld joints 26 of FIG. 2 . [0038] Referring to FIG. 8 , the conical nozzle 40 having the plurality of swaged L-channels 42 is shown in further detail. A plurality of tapered flow channels 56 are formed in the conical nozzle 40 . A manifold 54 is also shown which will collect fluid at a lower portion of the conical nozzle 40 for redirection of the fluid. The manifold 54 is known in the art and will therefore not be discussed in further detail herein. A downward flow direction arrow D and an upward flow direction arrow E are shown to designate that adjacent tapered flow channels 56 provide fluid flow in opposite directions. Flow in each tapered flow channel 56 in the downward flow direction arrow D will collect in the manifold 54 for redirection in the uppward flow direction arrow E. [0039] Referring to FIG. 9 , the plurality of swaged L-channels 42 are shown having a narrow radial spacing F. A full linking member thickness G is indicated in this upper section of the conical nozzle 40 for the channel linking members of the swaged L-channels 42 . Each of the swaged L-channels 42 has a radial member length J and a radial member thickness H. [0040] Referring to FIG. 10 , in a lower area of the conical nozzle 40 , each of the swaged L-channels 42 has a wide radial spacing L as shown. A reduced linking member thickness K results from forming the wide radial spacing L at this lower end of the conical nozzle 40 as more fully explained in reference to FIG. 11 herein. It should be noted that the radial member length J and the radial member thickness H are the same in this lower area as in the upper area of FIG. 9 . [0041] Referring now to FIG. 11 , an exemplary swaged L-channel 42 is shown having a radial member 58 and a linking member 60 . The radial member thickness H and the radial member length J are retained at both ends of the swaged L-channel 42 . The full linking thickness G (shown in FIG. 9 ) results at the narrow linking width M proximate end. The swaging process results in the reduced linking member thickness K (shown in FIG. 10 ) and the wide linking member width N distal end of the swaged L-channel 42 . It should be noted that the radial member thickness H of the radial member 58 is thinner than either the full linking member thickness G or the reduced linking member thickness K of the linking member 60 . As previously discussed, this permits the radial member 58 of each swaged L-channel 42 to rupture prior to a failure of the linking member 60 . Since the radial member 58 will rupture before either the linking member 60 or the conical jacket 46 , fluid is retained within the tapered flow channel 56 (shown in FIG. 8 ). [0042] Because of the increased stiffness from the structure of the L-shaped channels of the present invention, the number of L-shaped channels required to produce a nozzle assembly can be reduced from the quantity of tubes previously used for nozzles known in the art. In an exemplary embodiment, approximately 1,000 to approximately 1,100 tubes are required to produce a rocket nozzle having an upper diameter of approximately 76.2 cm (30 in) and a lower diameter of approximately 183 cm (6 ft). Using the L-shaped channels of the present invention, the number of L-shaped channels required for a similarly sized rocket nozzle is approximately 940. [0043] In a preferred embodiment of the present invention, material for the L-shaped channels comprises one of the “superalloy” materials, including an iron-nickel-chromium based A-286 material or a JBK 75 material. In a preferred embodiment, the jacket material is one of a JBK 75 or a nickel-chromium-iron 718 material. Other metals, including other alloys of nickel-chromium-iron, can be substituted for the materials of the present invention. Lower strength/temperature range materials, including stainless steels known in the art, can be substituted if a nozzle is designed for single use. The preferred materials of the present invention are selected to provide a nozzle design which is capable of reuse requiring a multiple cycle life. In a preferred embodiment, quartered sections of the nozzle are preassembled and are joined together to form each of the nozzle assemblies. Sections may be more or less than the quarter sections indicated at the discretion of the assembler. Construction of each nozzle from a plurality of sections allows a damaged nozzle assembly to be repaired by doing individual work on separate flow channels or by replacing an entire segment. The use of segments also permits a stock-pile of segments to be prepared in advance such that damage to a nozzle assembly under construction can be repaired using one of the segments. [0044] Referring to FIG. 12 , an inverted arrangement of L-shaped channels is shown. A plurality of channel linking members 62 form a nozzle outer surface 64 , and a jacket 66 (similar to the jacket 16 ) forms a nozzle inner surface 68 . Each of a plurality of channel radial members 70 extend radially inward from the nozzle inner surface 68 toward a central axis point 0 defining the nozzle geometric shape. A preformed tool (not shown) is constructed to constrain the arrangement of channel radial members 70 relative to the jacket 66 of this embodiment. Each of a plurality of longitudinal welds 72 is used to join the jacket 66 to a distal end 74 of each of the channel radial members 70 . Access to weld the plurality of channel linking members 62 is therefore available on the nozzle outer surface 64 . [0045] The L-shaped channel and jacket assembly of the present invention can also be used as a heat exchanger jacket around the perimeter of items requiring heat transfer. A cooling fluid can be circulated through the flow channels of the present invention in either a single pass or a double pass configuration. Nozzles assembled using the L-shaped channel and jacket of the present assembly can also be used in other applications including jet nozzles. [0046] The nozzle assembly of the present invention offers several advantages. The welded L-shaped channels of the present invention replace the brazed tubes known in the art. The tubes known in the art require a coating of nickel material to allow them to be brazed to each other. The coating step is also eliminated by the present invention. By designing each of the channel radial members with a reduced wall thickness, an over-pressure condition in one of the flow chambers results in a failure of the local channel radial member and contains leakage within the adjacent L-shaped channels of the nozzle assembly. By assembling a plurality of L-shaped channels using segments, an entire segment can optionally be replaced rather than attempting to individually repair a damaged section. [0047] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

A fluid flow nozzle is formed by a plurality of adjacent L-shaped channels forming successive channel pairs. Each channel has a linking member joined to a radial member. Each linking member is welded to an adjacent linking member forming a contiguous surface of linking members. Each radial member is oriented approximately perpendicular to a first side of the contiguous surface. A circumferentially enclosed chamber is formed on a second side of the contiguous surface. Each radial member is laser welded to a jacket at a distal end of each radial member. The jacket is oriented approximately parallel with the contiguous surface and separably spaced from the contiguous surface by the radial members. Each radial member forms one of a plurality of flow chambers between its adjacent radial member, the jacket and the contiguous surface. The flow chambers advantageously contain fluid in the event of a radial member rupture.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical press and in particular, to a flywheel subject to a possible axial movement during rotation. 2. Description of the Related Art Mechanical presses such as straight side presses and gap frame presses for stamping and drawing comprise a frame for reciprocal motion towards and away from the bed. The slide is driven by a crankshaft having a connecting arm connected to the slide to which is mounted the upper die. The lower die is mounted to a bolster which, in turn, is connected to the bed. Such mechanical presses are widely used for blanking and drawing operations and vary substantially in their the size and available tonnage, depending on their intended use. The primary source for stored mechanical energy in a mechanical press is a flywheel. The flywheel is located between the main drive motor and the clutch. The flywheel and the flywheel bearings are mounted on either the driveshaft, crankshaft, or the press frame by use of a quill. The train motor replenishes the energy lost from the flywheel during press stamping operations when the clutch couples the flywheel to the press driven parts. During engagement of the clutch, the flywheel drops in speed and the press driven parts come up to press running speeds. During engagement with the clutch, the press flywheel rotates in unison with the clutch while the flywheel bearings have no relative motion, except in the case of the use of the quill where relative motion is always present. One problem with current mechanical presses is that during operation, there may be axial movement of the flywheel as the flywheel rotates about the driveshaft, crankshaft, or quill. Axial movement of the flywheel may result in abnormal wear of bearings and other parts. For example, the quill can be scored if the axially moving flywheel's bushings contact the quill. SUMMARY OF THE INVENTION According to the present invention, a press includes a flywheel which is axially biased and centered to prevent axial movement of the flywheel along the quill or other member on which the flywheel is rotatably mounted. The invention, in one form thereof, is a hydrostatic biasing system for a flywheel. The system includes two thrust plates. One bronze thrust plate is secured to each side of the flywheel. At least one outboard hydrostatic bearing pad is located adjacent the thrust plates of the flywheel such that axial movement of the flywheel is limited. The invention, in another form, is a flywheel bearing to provide axial rotor guiding. The bearing includes a thrust plate secured to the flywheel on one of the two axial faces. A hydrostatic bearing pad is secured to the frame of the press and is adjacent the thrust plate of the flywheel such that axial movement of the flywheel is limited. The invention in a further embodiment, includes a bearing system to prevent axial movement of a flywheel which includes two thrust plates, one being attached to a hub of a flywheel on each of the two opposite axial faces. At least one hydrostatic bearing pad is attached to the press frame on either side of the flywheel outboardly adjacent the attached thrust plates, such that axial movement of the flywheel is limited. An advantage of the present invention is the prevention of damage to the quill or bushings during press operation. The present invention reduces and limits axial movement of the flywheel during its rotation. Consequently, the flywheel is provided with a true or balanced rotation. A non-balanced is flywheel may result in damage to the quill or the bushing by causing the bushing of the flywheel to make physical contact with the quill as the flywheel leans axially to one side or the other. This invention prevents that axial motion and therefore, prevents potential damage to the quill or other press member that the flywheel is mounted on. Another advantage of the present invention is a decrease or shortening of downtime of the press. Since the present invention prevents and reduces wear on the bearings, including the bushings and quill of a mechanical press, there will be less maintenance required to maintain the press in operating order. Consequently, there will be less downtime required to service the press. In addition, there will be a cost savings enjoyed by the diminished need for service and shortened downtime of the mechanical press. BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: FIG. 1 is an elevational front view of one configuration of a mechanical press incorporating the present invention in one form thereof; and FIG. 2 is a fragmentary vertical sectional view of the mechanical press of FIG. 1. Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings and particularly to FIG. 1, there is shown a mechanical press 10 comprising a crown 12, a bed portion 14 having a bolster assembly or slide 16 connected thereto and uprights 18 connecting crown portion 12 with bed portion 14. Uprights 18 are connected to or integral with the underside of crown 12 and the upper side of bed 14. A slide 20 is positioned between uprights 18 for reciprocating movement. Tie rods (not shown) extending through crown 12, uprights 18, and bed portions 14, are attached at each end with tie rod nuts (not shown). Leg members 24 are formed at an extension of bed 14 and are generally mounted on shop floor 26 by means of shock absorbing pads 28. A drive press motor 30, part of the drive mechanism, is attached by means of a belt 32 to main flywheel 36. Hydraulic oil pump 34 provides oil to provide lubrication between moving parts. Referring to FIG. 2, flywheel 36 is rotatable about quill 42 and is connected to crankshaft 46 by conventional combination clutch/brake assembly (not shown). Quill 42 is attached by bolt 38 to press frame or crown 12. The press crankshaft 46 rotates within quill 42. Gap 47 separates quill 42 from crankshaft 46. As known in conventional press art, crankshaft 46 is further connected to slide 20 by a connecting rod to cause rotational energy of crankshaft 46 to be translated into reciprocating movement of slide 20. Bearing bushing 54 is annularly disposed between quill 42 and flywheel hub 55 and forms a clearance 56 therebetween. Bearing bushing 54 has an internal bore which forms bearing surface 57. In the preferred embodiment, bearing bushing 54 is composed of bronze. Flywheel hub 55 is attached to flywheel web 58 of flywheel 36. Alternatively, flywheel hub 55 may be an integral piece with flywheel web 58 or with entire flywheel 36. A plurality of hydrostatic bearing pads 59 are located along quill 42. Hydrostatic bearing pads 59 open toward bearing surface 57. The present invention includes bronze thrust plates 60, 62 that are secured to a hub 55 of flywheel 36 by bolts 69 and 71, respectively. Alternatively, other fastening means may be employed for securing bronze thrust plates 60, 62 to hub 55. Bronze thrust plates 60, 62 are opposite hydrostatic bearing pads 64, 66 respectively. Hydrostatic bearing pad 64 extends from retainer 65. Bolt 67 fastens retainer 65 to quill 42. As shown, thrust plates 60 and 62 are disposed at respective axial face sections illustratively depicted at 73, 75 of the flywheel assembly (e.g., flywheel hub 55). In the preferred embodiment, oil is used for lubrication between moving parts, but equivalent other liquids or fluids may be utilized. Oil is applied through oil conduits 68 drilled through quill 42. A hydraulic oil pump 34 (shown in FIG. 1) is used to pressurize oil or fluid thereby causing pressurized fluid to flow through oil conduits 68 to quill 42 and hydrostatic pads 59, 64, 66. During operation of press 10, as flywheel 36 rotates about quill 42, hydrostatic pads 59 create hydrostatic bearing 70 between quill 42 and bearing surface 57. Pressurized fluid in sufficient quantity supplied through oil conduit 68 into hydrostatic pad 59, creates hydrostatic bearing 70. Consequently, metal-to-metal contact is eliminated. Thrust plates 60, 62 with hydrostatic pads 64, 66 respectively, limit or prevent axial movement of flywheel 36 along quill 42 as flywheel 36 rotates about quill 42. Hydrostatic pads 64, 66, when supplied with sufficient pressurized liquid, create hydrostatic bearings 72, 74, respectively, between hydrostatic pad 64, 66 and thrust plates 60, 62 whereby axial movement of flywheel 36 along quill 42 is prevented. In addition, hydrostatic bearings 72, 74 ensure that no metal-to-metal contact occurs. True rotation of flywheel 36 about quill 42 is achieved through the combination of hydrostatic bearing 70 and hydrostatic bearings 72, 74. Together, hydrostatic bearings 70, 72, 74 ensure flywheel 36 will rotate about quill 42 without axial movement along quill 42. Hydrostatic bearings 72, 74 exert axial force inward toward thrust plates 60, 62, respectively, thereby damping oscillations or jolts to flywheel 36 during its rotation. In addition, the hydrostatic bearings 70, 72, 74 ensure that flywheel 36 does not lean, tip, or become unbalanced along quill 42 as flywheel 36 rotates. As a result, true rotation of flywheel 36 is more closely achieved. While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

A flywheel quill with thrust plate and axial rotor guiding. Bronze thrust plates are attached to the hub of a flywheel and hydrostatic pads secured to the frame of a press are adjoining the bronze thrust plates, such that axial motion of the flywheel with attached thrust plates is limited and reduced.

BACKGROUND OF THE INVENTION This invention relates to vacuum booster devices for boosting automotive brake master cylinder by vacuum pressure and, more particularly, to improvements in those of the type comprising a booster shell, a booster piston axially slidably accommodated in the booster shell, first and second working chambers defined in the booster shell separately from each other by the booster piston, the first working chamber being held in communication with a vacuum source, the second working chamber being selectively placed in communication with the first working chamber or the atmosphere through a control valve means, an input rod mounted on the booster piston for forward and rearward movement with respect to the latter and connected to the control valve means so as to produce a pressure difference between both the working chambers for causing the booster piston to follow the forward movement of the input rod, tie rod means extending through the booster piston for connection of front and rear walls of the booster shell, seal means arranged between the tie rod means and the booster piston allowing operation of the piston, and a return spring compressed in the first working chamber for reinforcing the retraction of the booster piston. In the above-mentioned booster device, the booster shell can be protected from effect of the forward thrust loaded from output side by transmitting the thrust to the vehicle body through the tie rods so that such high rigidity as to bear the thrust loading need not be given to the booster shell, and advantageously, the shell can be formed light-weighted by using thin steel sheets, synthetic resins or the like as its base materials. However, in this known device, if the weight of the booster shell is lessened to an excessive degree, the booster shell may be outwardly deformed by the resilient force of the return spring of the booster piston in case of an unsupported booster device, central portion of the front wall of the booster shell defining the first working chamber may be inwardly deformed under the sucking action of the vacuum pressure when the pressure is accumulated in the first working chamber. SUMMARY OF THE INVENTION The present invention aims at overcoming the difficulties encountered in the prior art as described above and has for its primary object the provision of a new and improved vacuum booster device of the type described wherein the tie rods are arranged so as not to rotate and connection of the tie rods, master cylinder and vehicle body is readily carried out by means of nuts and bolts provided at both ends of the tie rods. The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings, which illustrate a presently preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a longitudinal cross-sectional view in side elevation of a preferred embodiment of a vacuum booster device in accordance with the present invention; and FIG. 2 is a cross sectional view taken along the line II--II in FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be explained hereinafter with reference to the drawings. In FIG. 1, a vacuum booster device, generally denoted by S, has a booster shell 1 which is composed of a pair of front and rear bowl-like parts 1F and 1R made of light thin steel plate or synthetic resin. The rear bowl-like part 1R has a plurality of projections 1a formed around an opening of the rear bowl-like part 1F at equal circumferential intervals. The projections 1a are fitted to a plurality of notches 1b formed around an opening of the front bowl-like part 1F at equal circumferential intervals so as to position both the bowl-like parts 1F and 1R in place. The parts 1F and 1R are connected together at their opposing front and rear walls through tie rods 30. At least two pieces of the tie rods 30 are disposed in a symmetrical arrangement about the axis of the booster shell 1 (See FIG. 2). The connection between the booster shell 1 and tie rods 30 will be described later. The interior space of the booster shell 1 is divided into a front side first working chamber A and a rear side second working chamber B by booster piston 2 axially slidably accommodated in the booster shell 1 and a piston diaphragm 3 formed of flexible material such as rubber or the like and joined to the rear face of the booster piston 2. The piston diaphragm 3 is of annular shape as a whole, and has annular beads 3a and 3b integrally formed, respectively, with outer and inner peripheral edges of the diaphragm 3 and respectively fitted in annular grooves 1c and 2a which are formed in a joining portion of both of the bowl-like parts 1F and 1R and in a rear face of the booster piston 2, respectively. The first working chamber A is always held in communication with a vacuum source, namely the interior of an intake manifold, not shown, of an associated internal combustion engine through a vacuum inlet pipe 4, while the second working chamber B is selectively placed in communication with the first working chamber A or in an air inlet port 6 open to the end wall 1e of a rearward extention tube 1d of the booster shell 1 through a control valve 5 which will be described later. The booster piston 2 is normally biased rearward, i.e., toward the second working chamber B by a return spring 7 arranged under compression in the first working chamber A. The rearward travel of the booster piston 2 under the spring bias is limited by projections 3e formed on the rear face of the piston diaphragm 3 being in abutting engagement with the inside surface of the rear wall of the booster shell 1. The fixed end of the return spring 7 is supported by a spring retainer plate 34 installed in abutment against the inside surface of the front wall of the booster shell 1. The booster piston 2 and the piston diaphragm 3 are respectively provided with through holes 31 and 32 for passing the tie rods 30 therethrough. The through hole 32 is open to the front face of the piston diaphragm 3 separable from the booster piston 2, and an annular bead 3c is integrally formed around a peripheral edge of the through hole 32. A tubular valve spring 8 axially extending from a central portion of the rear face of the booster piston 2 and integrally formed therewith is slidably supported by a plain bearing 9 provided in the extension tube 1d and the rear end of which is open to the air inlet port 6. The control valve 5 is constructed inside the tubular valve casing 8 in such a manner that an annular first valve seat 10 1 is formed on the front inside wall of the tubular valve casing 8, a valve piston 12 connected to an input rod 11 to form the front end of the latter is slidably fitted in the front part of the tubular valve casing 8, and an annular second valve seat 10 2 encircled by the first valve seat 10 1 is formed at the rear end of the valve piston 12. A cylindrical valve element 13 with its both ends opened is held at its base end portion 13a between the inside wall of the valve casing 8 and the outer periphery of a valve retainer sleeve 14 fitted inside the valve casing 8. The valve element 13 is formed of elastic material such as rubber or the like, and has a thin diaphragm 13b extending radially inwardly from the base end portion 13a, and a thick valve portion 13c formed at the inner peripheral end of the diaphragm 13b and opposed to the first and second valve seats 10 1 and 10 2 . The valve portion 13c is axially movable owing to the deformation of the diaphragm 13b and capable of abutting against the front end surface of the valve retainer sleeve 14. An annular reinforcing plate 15 is embedded in the valve portion 13c and is worked by a valve spring 16 for assisting the valve portion 13c in movement toward both the valve seat 10 1 and 10 2 . A space radially outside of the first valve seat 10 1 , a middle space between both the first and second valve seats 10 1 and 10 2 , and a space radially inside of the second valve seat 10 2 are always in communication with the first working chamber A through a through hole 17 formed in the booster piston 2, the second working chamber B through another through hole 18 in the piston 2 and the air inlet port 6 through the interior of the valve element 13, respectively. A large hole 19 is opened in a central portion of the front face of the booster piston 2 and a small hole 20 is opened at the recessed end of the large hole 19. An elastic piston 21 made of rubber or the like and an output piston 22 of the same diameter with the former are slidably fitted in the large hole 19 in the mentioned order from the recessed end thereof while a reaction piston 23 of a diameter smaller than that of the elastic piston 21 is slidably fitted in the small hole 20. A small shaft 12a projected from the front end surface of the valve piston 12 is protruded into the small hole 20 and opposed to the rear end surface of the reaction piston 23. The output piston 22 is integrally formed with a forwardly projecting output rod 22a. The input rod 11 is normally biased rearward by a return spring 24 and the rearward travel thereof is limited by a movable stopper plate 25 screw-fitted to the input rod 11 being in abutting engagement with the inside of the end wall 1e of the rearward extension tube 1d. Axial location of the input rod 11 with respect to the screw-fitted movable stopper plate 25 is changed by turning the latter and accordingly the retracting limit of the input rod 11 can be adjusted in both forward and rearward directions. The movable stopper plate 25 after being thus adjusted in position is fixed by fastening a lock nut 26 also screw-fitted to the input rod 11. The movable stopper plate 25 is provided with an air vent 27 for preventing the blocking of the air inlet port 6. Air filter elements 28 and 29 are fitted in the outer end opening of the tubular valve casing 8 for purifying the air induced through the air inlet port 6 and are transformable so as not to hinder the operation of the input rod 11. The mechanism for connection of the tie rods 30 and the booster shell 1 will be described hereinafter. The spring retainer plate 34 is kept from turning by fitting the two tie rods 30 in both the front and rear walls of the booster shell 1 together with the aid of a pair of bosses 34a integrally projected at both the ends of the spring retainer plate 34. An intercepted round concave hole 60 is provided in each of the inner ends of the bosses 34a and an intercepted round flange 61 disposed on each tie rod 30 is fitted in the concave hole 60 so that the tie rod is kept from turning. Further, each of the outer ends of the bosses 34a is provided with a concaved seal housing 37 wherein the tie rod 30 is fitted with a retaining ring 62 for holding the boss 34a by cooperating with the flange 61. The seal housing 37 is filled with a sealing material 38 to be used for sealing the tie rod through hole opened in the front wall of the booster shell 1. In this way, the spring retainer plate 34 is connected with the tie rods 30, so that the resilient force of the return spring 7 is loaded on the tie rods 30 and the central portion of the front wall of the booster shell 1 is kept from being inwardly deformed. On the other hand, a stepped flange 41 on each of the tie rods 30 is fitted in each of support cylinders 43 welded to the inside surface of the rear wall of the booster shell 1. The support cylinder 43 is inserted therein each tie rod 30 and is fitted with the retaining ring 62 for holding the stepped flange 41 by cooperating with the rear wall of the booster shell 1. An annular housing 44 defined between a smaller diameter portion of the stepped flange 41 and the support cylinder 43 is filled with a sealing material 45 to be used for sealing the tie rod through hole in the rear wall of the booster shell 1. Both the ends of the tie rod 30 projected outwardly from the front and rear sides of the booster shell 1 are respectively formed as mounting bolts 33 and 39. The tie rod 30, spring retainer plate 34, front wall of the booster shell 1 and a mounting flange 36 of the brake master cylinder M are connected together by tightly screwing the nut 35 on the tip end of the front mounting bolt 33 extended through the mounting flange 36 overlaid on the front surface of the booster shell 1, while the tie rod 30, rear wall of the booster shell 1 and front wall W of the compartment are connected together by tightly screwing the nut 40 on the tip end of the rear mounting bolt 39 extended through the front wall W of the automobile compartment. As mentioned above, the tie rod 30 is kept from turning by fitting engagement of the intercepted round concave hole 60 of the spring retainer plate 34 with the intercepted round flange 61 and the spring retainer plate 34 is also kept from turning by means of the two tie rods so that in tightening the nuts 35 and 40, the nuts 35, 40 and the tie rod 30 are prevented from being turned together to assure a secure tightening of the nuts 35 and 40. A sealing means is arranged between the booster piston 2 and the tie rod 30 for sealing the through hole 31 of the booster piston 2 with the tie rod 30 inserted therein in such a manner as not to hinder the operation of the booster piston 2. The sealing means comprises a flexible bellows 46 made of elastic material such as rubber or the like. The bellows 46 surrounds the tie rod 30 inside the front working chamber A, and the front and rear ends 46a and 46b of the bellows 46 are tightly fixed to an annular groove 47 located at the outer periphery of the front end of the tie rod 30 and to the through hole 31 in the booster piston 2, respectively. Further, the through hole 32 is sealed with the bellows 46 by closely but separably mating the rear end 46b of the bellows 46 and the front surface of the annular bead 3c of the piston diaphragm 3. Inside the compartment, a brake pedal 52 pivoted at 51 on a fixed bracket 50 is connected to the rear end of the input rod 11 of the booster device S through an adjustable pedal link 53. Reference number 54 indicates a return spring for rearwardly biasing the brake pedal 52. Rear end of a cylinder body 55 of the brake master cylinder M is extended through the front wall of the booster shell 1 and protruded into the first working chamber A while rear end of a working piston 56 inside the cylinder body 55 is opposed to the output rod 22a of the booster device S. Description will next be made of the operation of the embodiment described above. The drawings show the state of the booster device not in operation, wherein the valve piston 12, the input rod 11 and the brake pedal 52 linked with one another are returned to the prescribed retractive position where the movable stopper plate 25 is abutted against the fixed end wall 1d and held in the position under the resilient force of the return spring 24. Front face of the valve portion 13c is pushed by the valve piston 12 through the second valve seat 10 2 and is retracted until it is slightly touched on the front face of the valve retainer sleeve 14, whereby a little clearance g is made between the first valve seat 10 1 and the valve portion 13c. Such state can easily be obtained by adjusting the aforesaid movable stopper plate 25. Consequently, during running of the engine, the first working chamber A always accumulating vacuum pressure therein is placed into communication with the second working chamber B through the through hole 17, clearance g and through hole 18, and the front opening of the valve portion 13c is closed by the second valve seat 10 2 , so that the vacuum pressure in the first working chamber A is transmitted to the second working chamber B to obtain equilibrium of the pressures in both the working chambers A and B. The booster piston 2 is therefore located in the retracted position as shown in FIG. 1 by the resilient force of the return spring 7. In the brake operation, when the brake pedal 52 is depressed and the input rod 11 and the valve piston 12 are advanced, the valve portion 13c forwardly biased by a valve spring 16 follows the advancement of the valve piston 12 to also move forwardly. However, since the clearance g between the first valve seat 10 1 and the valve portion 13c is very narrow as referred to above, the valve piston 13c is immediately seated on the first valve seat 10 1 to close the communication between both the working chambers A and B and at the same time the second valve seat 10 2 is separated from the valve portion 13c to connect the second working chamber B with the air inlet port 6 through the through hole 18 and interior of the valve element 13. Thus, the ambient air is induced into the second working chamber B without delay and the pressure in the chamber B becomes higher than that in the first working chamber A, whereby, owing to the pressure difference between both the chambers A and B, the booster piston 2 is moved forwardly against the return spring 7 to advance the output rod 22a through the medium of the elastic piston 21 so that a working piston 56 of the brake master cylinder M is forwardly driven to brake the vehicle. On this occasion, the rear end 46c of the bellows 46 is forcibly contacted with the annular bead 3c on the piston diaphragm 3 by the pressure difference between both the working chambers A and B, so that the communication between both the working chambers A and B are securely cut off. When the working piston 56 is driven, the forward thrust load is applied to the cylinder body 55 as described above and is then transmitted to the vehicle body through the tie rod 30, that is, the front wall W of the compartment and supported by the wall W. The load is, therefore, not applied to the booster shell 1. On the other hand, when a small shaft 12a of the valve piston 12 is advanced to abut against the elastic piston 21 through the reaction piston 23, the reaction force of the output rod 22a is partly fed back to the side of the brake pedal 52 through the valve piston 12 owing to the expansion of the elastic piston 21 toward the side of the reaction piston 23 caused by the reaction force of the output rod 22a, so that the output of the output rod 22a or the braking force can be detected by drivers. Subsequently, when the depression on the brake pedal 52 is released, the input rod 11 is first retracted under the reaction force acting on the valve piston 12 and the resilient force of the return spring 24, then the second valve seat 10 2 is seated on the valve portion 13c which is simultaneously placed into abutment against the front face of the valve retainer sleeve 14 and the axial compressive deformation of the valve body 13c is produced under the retractive force of the input rod 11. As the result, a clearance larger than the initial clearance g is produced between the first valve seat 10 1 and the valve portion 13c to equalize the pressures of both the working chambers A and B without delay. When the above pressure difference disappears, the booster piston 2 is retracted under the resilient force of the return spring 7 and is stopped as projections 3b of the piston diaphragm 3 are abutted against the inside surface of the rear wall of the booster shell 1. When the input rod 11 is abutted against the end wall 1d, the valve portion 13c is released from the retractive force of the input rod 11 and restored to the original shape, so that the above clearance can be again narrowed to be the original one g. If the brake pedal 52 is depressed to advance the booster piston 2 in the case where the vacuum pressure is not yet accumulated in the first working chamber A, the air remaining in the first working chamber A which has not been discharged into the vacuum supply source because of the resistance inside the pipe line or the like is compressed. When air pressure of the second working chamber B is exceeded by that of the first working chamber A, a portion of the remaining air inside the first working chamber A enters a space between the rear surface of the booster piston 2 and the piston diaphragm 3 to push the annular bead 3c around the through hole 32 so as to separate the latter from the rear end 46b of the bellows 46, as a consequence of which both the working chambers A and B are placed in communication with each other through thus formed clearance between the annular bead 3c and the rear end 46b of the bellows 46 and through the through hole 32 of the piston diaphragm 3. Therefore, such troubles as the rearward swelling transformation of the piston diaphragm 3 caused by an excessive rearward pushing force can be prevented since the air pressures in both the working chambers A and B become immediately balanced with each other through the clearance and the through hole 32. When the above pressure difference is eliminated, the annular bead 3c is again placed into close contact with the rear end 46c of the bellows 46. As has been described, according to the present invention, tie rod means connecting the front and rear walls of the booster shell is connected to the spring retainer plate which is adapted to support the fixed end of the return spring, so that the resilient force of the return spring can be chiefly loaded on the tie rod means through the spring retainer plate, thus preventing the resilient force from being loaded on the booster shell. Further, since the spring retainer plate connected to PG,19 the tie rod means is abutted against the inside surface of the front wall of the booster shell, the front wall of the booster shell can be prevented from deformation due to the sucking action of vacuum pressure in the booster shell and any possible inconveniences accompanied by light-weighted arrangement of the booster shell can be eliminated. In this regard, the spring retainer plate can be made of light material such as aluminum alloy or synthetic resin or the like, which produces only a little increase in weight of the device as a whole. In addition, the tie rod means has at least two tie rods, each of which is connected to the spring retainer plate in a rotation-proof manner, so that both the tie rods and the spring retainer plate cooperate with one another to ensure a firm fixation of respective tie rods in a non-rotatable condition. Therefore, when the tie rods are connected with the master cylinder by use of the mounting bolts and nuts disposed at both the end portions of the tie rods, such connecting work can be carried out easily and securely without causing any rotation of the tie rods. In consequence, any specific anti-rotating means need not be arranged between the booster shell and tie rods, which are formed thin and have relatively low mechanical strength, to advantageously contribute to maintenance of the durability of the booster shell and of the sealability of the tie rod through hole.

A highly durable and light-weighted vacuum type brake booster device including a booster shell, a booster piston axially slidably accommodated in the booster shell to divide the interior thereof into a first chamber communicating with a vacuum source and a second chamber adapted to be placed into selective communication through a control valve with the first chamber and the atmosphere, and an input rod operatively connected with the control valve for operating the latter to generate a pressure differential between the first and second chambers. The front and rear walls of the booster shell are connected with each other by means of tie rod(s) which extend(s) through the booster piston with a deformable seal member disposed therebetween. The booster piston is urged in a retracting direction by a return spring disposed in the first chamber. A retainer plate for supporting one end of the return spring abuts against the front wall of the booster shell to prevent the vacuum deformation thereof and is secured to the tie rod so that the resilient force of the spring is shared by the tie rod to avoid any excessive loading on the booster shell.

RELATED APPLICATIONS Applicant claims the benefit of U.S. provisional patent application 60/855,976 filed Nov. 1, 2006, for a Lock Guard for Long Shackle Padlock Over Handle. BACKGROUND OF THE INVENTION Thieves who break into moving vans, tractor trailers and other cargo containers use a variety of tools such as sledge hammers, acetylene cutting torches, saws, grinders and the like. The bolt cutter is a favored tool of burglars for cutting padlocks because of its portability and reduced time, light and sound generation; thus there is a need to protect padlocks used on containers, moving vans, semi-trailers, truck trailer units and storage facilities. Tractor trailers with twin rear doors are secured by a pair of vertical stanchions, at least one of which has a locking handle or lever, which is normally secured by padlock to prevent rotation of the stanchion, thus maintaining the doors in a locked condition. It is also desirable to provide protection for padlocks securing similar operating levers of doors of containers or storage facilities. It is desirable to keep the lock guard relatively small to make it more difficult for thieves to access the lock. Additionally, it is important to some container owners, due to the high value or sensitivity of their loads, to shield the retainer catch and pivoted locking latch because those components can be cut to gain entry while leaving the lock untouched. BACKGROUND ART Various attempts have been made to protect padlocks securing stanchion locking levers for roll-up doors and the like. U.S. patents showing devices attempting to protect padlocks include Eberly U.S. Pat. Nos. 4,581,907 and 4,898,008; Ankovitz U.S. Pat. No. 1,224,404; Ellington U.S. Pat. No. 1,248,293; Sole U.S. Pat. No. 5,737,946; Santini U.S. Pat. No. 6,622,533; Stroudtman U.S. Pat. No. 6,581,419; Brammall U.S. Pat. No. 6,519,982; Hamilton U.S. Pat. No. 6,010,166; Emmons U.S. Pat. Nos. 5,118,149 and 6,009,731; Van Buren U.S. Pat. No. 6,357,266 and Gogel U.S. Pat. Nos. 7,201,027 and 7,201,028. The rear wall of the lock guard of Santini U.S. Pat. No. 6,622,533 includes a back wall having a pair of handle engaging members used to hook the lock guard to the locking handle. SUMMARY OF THE INVENTION The herein disclosed lock guard shrouds the padlock's shackle when fully engaged and secured so as to protect the lock from unauthorized tampering when securing a semi-trailer or container door in its closed position. The security device allows the door to be secured with both a padlock and said lock guard in seconds. The relatively long vertical length of the guard envelops and protects the retainer catch and latch and locking the guard's downwardly extending securing tabs at its laterally opposite sides extending below and behind the locking handle secures the guard in its protecting position. The lock guard has a pitched roof to deflect physical attack. By providing a latching abutment and a narrow vertical slot in the front wall, the lock guard can be used in conjunction with a longer shackled padlock without providing the normal offset in expanded fore and aft width. It allows the insertion of the longer shackle into a locking tab hole in a functionally and significantly smaller housing dimension. The slot's design is sufficiently narrow as to prevent insertion of an adult human finger and the overall design is such that fingers and hands are not only not needed for inclusion of the lock in the guard on the secured enclosure but also thwarted by its compact design. Additionally, the lock guard is fully portable and does not require a time sensitive feeding of the locking handle through the guard, as required by a prior art guard. The device capitalizes on the hinged shackle of the padlock. The guard is not directly secured to the door. It does allow for a broader range of length of padlock shackles, it does engulf and protect the lock's shackles, and independent movement of the guard is severely retarded by the securing tabs that are slid behind the door's locking handle and which work in concert with both the locking handle and the associated padlock to thwart excessive movement. BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in the accompanying drawings, in which: FIG. 1 is a perspective showing the rear doors of a semi-trailer secured by stanchions, one of which has an operating lever secured by a lock protected by a lock guard of this invention; FIG. 2 is a front view of the installed lock guard shown in FIG. 1 ; FIG. 3 is a side view of the installed lock guard shown in FIG. 2 ; FIG. 4 is a section taken on line 4 - 4 in FIG. 2 ; FIG. 5 is a rear view of the lock guard shown in FIG. 2 ; FIG. 6 is a bottom view of the lock guard shown in FIG. 2 ; FIG. 7 is a side view of the lock guard shown in FIG. 2 ; FIG. 8 is a side view of a second embodiment lock guard; FIG. 9 is a vertical section showing the lock guard of FIG. 8 installed in a lever securing position, and FIG. 10 is a vertical section showing a padlock being connected to the lock guard of FIGS. 2 through 7 . DETAILED DESCRIPTION OF THE INVENTION The lock guard 11 shown in FIGS. 1 through 7 and 10 has particular utility in protecting a lock shackle padlock 34 securing an operating lever 13 pivotally connected to a vertical stanchion 14 of a semi-trailer 16 shown in FIG. 1 . As illustrated, a stanchion lever 14 ′ also has an operating lever 13 ′ and a lock guard 11 ′. The stanchion lever 13 of the semi-trailer truck 16 is pivotally connected to the stanchion 14 on a horizontal axis and, as shown in FIGS. 1 through 4 , is flat on the side near the secured door 17 and is flat on the side facing away from the door 17 . As shown in FIGS. 3 and 4 , the lever 13 , in its locking position, is nested in an upwardly open recess 18 of a locking flange 21 projecting from the exposed side of a latch plate 22 secured to the door 17 by bolt like fasteners 23 , 24 . The stanchion lever 13 is secured in its illustrated door locking position by a retainer latch 26 pivotally connected to the latch plate 22 by the fastener 24 . The locking flange 21 and the pivotable retainer latch 26 have vertically alignable annular openings 31 , 32 , respectively, in their locking positions, through which a shackle 33 of a padlock 34 extends, as shown in FIG. 6 , to maintain the lever 13 in its stanchion locking position. As illustrated in FIGS. 1 through 7 and 10 the lock guard 11 has a housing which includes a vertical front wall 41 , a pair of parallel vertical side walls 42 , 43 rigidly secured to and extending rearwardly at right angles from the front wall 41 , a double pitched roof 46 rigidly secured to the upper ends of the front wall 41 and the side walls 42 , 43 . The laterally opposite sides of the roof slope upwardly from the sidewalls 42 , 43 at 45 degree angles converging in a fore and aft extending peak. The sloping roof 46 is designed to deflect sledge hammer blows impacted by thieves. As shown in FIGS. 3 and 7 , side wall 42 includes a bottom open rectangular notch 52 at its lower rear corner and as shown in FIGS. 4 and 10 side wall 43 includes a similar notch 53 at its lower rear corner. The bottom open notches 52 , 53 accommodate the lever 13 when the lock guard 11 is in its installed position, as shown in FIGS. 3 and 4 . The lock guard 11 is also provided with a partial bottom floor 56 which may have a central notch 57 at its rear end. The horizontal bottom floor 56 is rigidly secured at its front and laterally opposite sides to the front wall 41 and side walls 42 , 43 . The partial bottom floor 56 limits access and reinforce the side walls 42 , 43 . The notch 57 , if included, accommodates the case 35 of the long shackle padlock 34 . The lock guard 11 includes a horizontal retainer tab 61 , rigidly secured to the front wall 41 and the side walls 42 , 43 , which has an annular vertical opening 62 for reception of the shackle 33 of the padlock 34 . A horizontal abutment or abutment plate 66 is rigidly secured to the walls 41 , 42 , 43 and is disposed above the retainer tab 61 so as to provide an abutment which is engaged by the shackle 33 when it is desired to lock the padlock 34 in its installed condition shown in FIG. 4 . As shown in FIGS. 2 , 3 and 4 , the lock guard 111 surrounds and protects the latch plate 22 and the pivoted retainer latch 26 as well as the padlock 34 . As shown in FIG. 2 , the lock guard 11 is horizontally wider than the latch plate 22 and the retainer 26 latch in its illustrated locking position. A pair of L-shaped brackets 71 , 72 have horizontal legs 73 , 74 welded to the laterally outer sides of the side walls 42 , 43 , respectively. The horizontal legs 73 , 74 are in horizontal alignment with, and are structurally an extension of, the retainer tab 61 . The L-shaped brackets 71 , 72 at the rear of the lock guard housing have downwardly extending vertical legs 76 , 77 which are insertable vertically downward behind the stanchion lever 13 , thereby retaining the lock guard 11 close to the door 17 in a protective position relative to the padlock 34 , the latch plate 22 and the pivotable retainer latch 26 . The legs also resist attempts to remove the lock guard 11 by pry bars. The horizontal legs 73 , 74 of the brackets 71 , 72 also reinforce the side walls 42 , 43 and the retainer tab 61 . The lock guard 11 is designed for use with either the illustrated long shackle padlock 34 or a regular length shackled padlock, not shown. A vertically elongated slot 81 is provided in the front wall 41 in which the shackle 33 of the long shackle padlock 34 is temporarily inserted, in order to permit the unhinged leg of the shackle 33 to be inserted in the opening 62 in the retainer tab 61 , while retaining succinctness and restricting the normal expansion of lock guard 11 to accommodate such length lock guard shackle 33 . The slot 81 is slightly wider than the diameter of the shackle 33 , but too narrow for an adult human finger. A second type of stanchion lever 113 shown in FIG. 9 , has a horizontally projecting reinforcing ridge 118 with a vertical opening 133 . A second embodiment lock guard 111 , shown in FIGS. 8 and 9 , is particularly suited for use in guarding the padlock 34 used to secure the stanchion lever 113 . The presence of the ridge 118 requires notches 152 , 153 in the side walls 142 , 143 which have a wider horizontal width than the notches 52 , 53 of the lock guard 11 . In other respects the lock guard 111 is similar to the lock guard 11 . The lock guard 111 includes L-shaped brackets 171 , 172 , similar to brackets 71 , 72 , which have downward extending legs 176 , 177 which hook behind the stanchion lever 113 in the same manner as the legs 76 , 77 of the lock guard 11 hooked behind the stanchion lever 13 . The latch plate 122 shown in FIG. 9 , to which the retainer latch 126 is pivotally connected, includes a locking flange 121 with a pocket 124 for the receiving stanchion lever 113 in its locking position. The pivotable retainer latch 126 and the stanchion lever 113 have alignable openings 132 , 133 for reception of the shackle 33 of the padlock 34 . The front wall 141 of the lock guard 111 includes a vertically elongated opening 181 . Guard 111 also includes a retainer tab 161 with a vertical opening 162 for the shackle 33 of the padlock 34 and an abutment plate 166 . FIG. 10 illustrates the utility of the vertically elongated opening 181 in the front wall 141 of the lock guard 111 , whereby the shackle 33 is temporarily placed at least partially in the opening 181 during insertion of the shackle 33 through the opening 162 in the retainer tab 161 in preparation of securing the stanchion lever 113 . The shackle 33 is also insertable into the opening 181 when removing the padlock 34 from the lock guard 111 . An abutment 166 is rigidly secured to the side walls 142 , 143 and the front wall 141 and is disposed above the horizontal retainer tab 161 . Having hereby described the subject matter of the present invention, it should be apparent that many substitutions, modifications and variations of the invention are possible in light of the above teaching. It is therefore to be understood that the invention as taught and described herein is only to be limited to the extent of the breadth and scope of the appended claims.

Two embodiments of a guard are provided for protecting a padlock securing stanchion levers in their door locking position. An opening in the front wall of the guard permits its use with padlocks having long shackles as well as those with regular length shackles while retaining the compactness not normally retained for the extended length of the shackles. The preferred construction lock guard has a pitched roof and a pair of legs on its laterally outer sides extending downwardly behind the stanchion lever at laterally opposite sides of the stanchion latching mechanism that increase stability, rigidity of the housing and protection of the latches.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable telephone apparatus, and more particularly to a portable telephone apparatus which protects stored contents of an internal memory when power supply from a cell is disconnected instantaneously. 2. Description of the Related Art It is a significant factor for a portable telephone apparatus to keep a telephone directory, accounting information, data of duration of a call and so forth. Various portable telephone apparatus which protect stored contents of an internal memory when power supply is disconnected instantaneously are known and disclosed, for example, in the following documents. Japanese Patent Laid-Open No. 55979/1993: Prior Art 1 An interface for allowing information to be read in from an external storage apparatus prepared separately is provided on the body of a portable telephone set such that, even if stored contents of an internal memory are erased, information can be written into the internal memory newly from the external storage thereby to eliminate the necessity for a backup power supply for the internal memory. Japanese Patent Laid-Open No. 95324/1993: Prior Art 2 A memory is provided in a charger, and upon charging by the charger, information stored in the memory is transferred to an internal memory of a portable telephone apparatus thereby to eliminate the necessity for a backup power supply for the internal memory. Japanese Patent Laid-Open No. 6283/1994: Prior Art 3 A portable telephone set includes a battery for emergency separate from a battery for use for ordinary call, and a telephone number for emergency call is registered in advance in an internal memory backed up by a backup battery. If the registered telephone number for emergency call is inputted, then the power supply is changed over from the battery for ordinary call to the battery for emergency call thereby to allow emergency call even if the battery for ordinary call is consumed. Japanese Patent Laid-Open No. 55781/1997: Prior Art 4 A buffer memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), a voltage holding capacitor and a voltage detection circuit for detecting the voltage of a power supply cell are provided in the body of a portable telephone set. During a call, data to be stored are written into the buffer memory, and when the call comes to an end, the data written in the buffer memory are transferred to the EEPROM. If the voltage detection circuit detects that a necessary voltage is not obtained from the cell because the cell is removed or consumed, the buffer memory and the EEPROM are operated with the voltage held by the capacitor to transfer the data written in the buffer memory to the EEPROM. Japanese Patent Laid-Open No. 139981/1997: Prior Art 5 A telephone number of the call origination side is stored, during a call, into an EEPROM so that it may be maintained even if the call is interrupted because of exhaustion of a cell. Then, when the power supply becomes available as a result of replacement of the cell with a new cell, the telephone number is read out from the EEPROM and displayed on a display section. Japanese Patent Laid-Open No. 294330/1997: Prior Art 6 The number of voltage variations of a backup cell is counted, and the life of the backup cell is estimated from the count value and conveyed to the user. Japanese Patent Laid-Open No. 177481/1999: Prior Art 7 A portable telephone set includes a main battery, a backup battery for backing up an SRAM (static random access memory) which stores a telephone number, a voltage detector for detecting the voltage of the main battery and causing a CPU to perform system resetting when it detects the lowest operating voltage, and a switch element. Upon system resetting, the switch element is switched off thereby to prevent a voltage drop by reverse current to assure the backup for the SRAM and so forth. Most portable telephone apparatus include a cell and a cell cover formed as a unit. In a portable telephone apparatus of the type just mentioned, the cell is removed inadvertently by a shock upon replacement or when the cell cover is dropped. Therefore, an SRAM (static random access memory) which maintains its stored data as long as power is supplied thereto is used and backed up by a primary or secondary cell to protect the stored data so that they may not be lost inadvertently. The backup current for an SRAM is approximately 1 μA and very low. In contrast, the backup current for a DRAM (dynamic random access memory) which is less expensive is approximately 100 μA and comparatively high. Consumption of high current decreases the life of a cell of a telephone apparatus. Therefore, it is obliged to avoid replacement of an SRAM with a DRAM. Meanwhile, where a cell and a cell cover are formed as a unit, cell covers of different colors must be prepared for different colors for the body of a portable telephone apparatus, and the number of parts to be managed becomes great as much. If the cell and the cell cover are formed so as to be separable from each other or formed as separate parts, then the number of parts to be managed depending upon the different colors can be reduced. Further, in recent years, as a result of popularization of the Internet, a portable telephone apparatus has become popularized which has a higher performance as a result of incorporation of a browser function (software for accessing the Internet) or as a result of additional incorporation of a color display function and therefore requires an internal memory of a large capacity. However, since the price competition is very keen, it is demanded to use electronic parts of reduced costs. In the portable telephone set of the Prior Art 4 (Japanese Patent Laid-Open No. 55781/1995) from among the prior art documents given hereinabove, if a necessary voltage is not obtained from a cell because the cell is removed or consumed, then the buffer memory and the EEPROM are operated with the voltage held by the voltage holding capacitor to transfer the data written in the buffer memory to the EEPROM as described above. Therefore, a DRAM can be used for the buffer memory. However, since a capacitor of a high capacitance is required as the voltage holding capacitor, this makes miniaturization of the portable telephone set difficult. Besides, even if a capacitor of a high capacitance is used, since this allows backup of data only of several tens bytes, it cannot be used to back up information of a great amount of data such as a telephone directory which likely contains data of several tens kilobytes. SUMMARY OF THE INVENTION It is an object of the present invention to provide a portable telephone apparatus wherein, when a necessary voltage is not obtained from a cell because the cell is removed or consumed, data can be backed up with a simple configuration and at a low cost. The present invention has been made from the points of view that a cell and a cell cover are preferably formed as separate parts and that a considerable interval of time is available after the cell cover is opened until the cell is removed. Thus, in order to attain the object described above, according to the present invention, there is provided a portable telephone apparatus, comprising a body having an accommodation portion capable of accommodating a cell serving as a power supply therein, a cell cover removably attached to the body for opening and closing the accommodation portion, a volatile memory which requires backup by the cell, a non-volatile memory which does not require backup by the cell, cell cover opening/closing detection means for detecting opening or closing of the cell cover with respect to the accommodation portion of the body, and transfer means for transferring stored contents of the volatile memory to the non-volatile memory when opening of the cell cover is detected by the cell cover opening/closing detection means. The cell cover opening/closing detection means may include a switch which is switched on or off when the cell cover opens or closes the accommodation portion of the body or alternatively may include a Hall effect element or a reed relay which is operated by a magnet provided on the cell cover. Preferably, the portable telephone apparatus further comprise cell remaining power detection means provided on the body for detecting a remaining power of the cell and outputting a cell remaining power detection signal when the remaining power of the cell decreases to a predetermined value. In this instance, the transfer means transfers the stored contents of the volatile memory to the non-volatile memory when the cell remaining power detection signal from the cell remaining power detection means is inputted to the transfer means. Where the volatile memory is a RAM and the non-volatile memory is a flash ROM, when the cell cover opening/closing detection means detects opening of the cell cover or when the cell remaining power detection signal from the cell remaining power detection means is inputted to the transfer means, the transfer means transfers the stored contents of the RAM to the flash ROM by an interrupt process by a CPU. The volatile memory may be a DRAM. Therefore, in the portable telephone apparatus, a DRAM and a flash ROM which are less expensive can be used for the memory for keeping data in place of an expensive SRAM. The transfer means may include a circuit for producing an interrupt signal to the CPU from a cell cover opening detection signal from the cell cover opening/closing detection means and the cell remaining power detection signal from the cell remaining power detection means. Preferably, the portable telephone apparatus further comprises a display section provided on the body for displaying a warning when the cell remaining power detection signal is outputted from the cell remaining power detection means. The portable telephone apparatus achieves the following advantages in practical use. In particular, since data of the volatile memory, that is, a RAM, are transferred to and protected by the non-volatile memory, that is, a flash ROM before the cell is disconnected instantaneously, it is not necessary to maintain the data in the RAM. Further, since opening/closing of the cell cover can be detected by the cell cover opening/closing means of a comparatively simple configuration, no considerable effect is had on the cost. Furthermore, ID information of a portable telephone apparatus is information unique to the portable telephone apparatus and must always be maintained, and the ID information is usually stored in a flash ROM. Therefore, the flash ROM used in the present portable telephone apparatus does not make a factor of increase of the cost. Accordingly, it is not necessary to normally back up data in the RAM with the cell, and therefore, a less expensive DRAM can be used as the RAM, that is, the volatile memory. Since various factors of increase of the cost are eliminated in this manner, reduction of the cost can be anticipated. Furthermore, even if the cell is disconnected, it is not necessary to continue supply of power to the RAM, and therefore, a cell for exclusive use for backing up the RAM is not required and the cost can be reduced as much. The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference symbols. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an electric configuration of a portable telephone apparatus to which the present invention is applied; FIG. 2 is a perspective view showing a mechanical configuration of the portable telephone apparatus to which the present invention is applied; and FIG. 3 is a block diagram showing a detailed configuration of a control circuit shown in FIG. 1 . DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1 , there is shown an electric configuration of a portable telephone apparatus to which the present invention is applied. The portable telephone apparatus shown includes a cell 13 serving as a power supply, a cell cover opening and closing detection apparatus 1 for detecting opening and closing of a cell cover (not shown in FIG. 1 ) separate from the cell 13 , a cell remaining power detection apparatus 2 , a control circuit 5 , a CPU (central processing unit) 7 , a display apparatus 9 , a flash ROM 10 which is a non-volatile memory, a RAM 11 which is a volatile memory, and a bus 12 . The cell cover opening and closing detection apparatus 1 detects removal or opening of the cell cover before the cell 13 is removed, that is, before power supply by the cell 13 is disconnected, and outputs a cell cover opening/closing detection signal 3 . The cell remaining power detection apparatus 2 outputs a cell remaining power detection signal 4 when the remaining power of the cell 13 decreases below a predetermined value. The cell cover opening/closing detection signal 3 outputted from the cell cover opening and closing detection apparatus 1 and the cell remaining power detection signal 4 outputted from the cell remaining power detection apparatus 2 are inputted to the control circuit 5 . Further, an interruption signal 6 and another interruption signal 8 corresponding to the signals 3 and 4 , respectively, are outputted from the control circuit 5 to the CPU 7 . The CPU 7 receives the interruption signal 6 representative of opening of the cell cover and performs operation of writing data stored in the RAM 11 into the flash ROM 10 before the cell 13 is removed and the power supply is disconnected. The flash ROM 10 can maintain data even if there is no power supply thereto. Since at least several seconds are taken after removal of the cell cover till disconnection of the cell 13 , the data can be transmitted from the RAM 11 to the flash ROM 10 sufficiently in time. Further, if the remaining power of the cell 13 decreases below the predetermined value, then this is detected by the cell remaining power detection apparatus 2 . Consequently, data stored in the RAM 11 in advance can be written into the flash ROM 10 before the remaining power of the cell is used up. In this instance, a warning that the remaining power of the cell 13 is little can be given to the user by means of the display apparatus 9 . Further, updating of the data of the RAM 11 after the cell is removed is not performed. Accordingly, the necessity to protect data stored in the RAM 11 is eliminated. Consequently, the necessity to use a high price SRAM is eliminated, and the RAM 11 can be replaced by a low price DRAM. In other word, the RAM 11 can be formed not from an SRAM but from a DRAM. Referring now to FIG. 2 , there is shown a mechanism of part of the portable telephone apparatus to which the present invention is applied. The portable telephone apparatus includes an antenna 14 provided at an end of a body 17 of a generally thin substantially rectangular parallelepiped, and a cell accommodation section 17 a is provided at an internal portion of a rear face of the body 17 remotely from the antenna 14 . A thin cell 13 is removably accommodated in the cell accommodation section 17 a , and the cell accommodation section 17 a is closed with a cell cover 15 with the cell 13 accommodated therein. The cell cover 15 is freely attached to or removed from the body 17 . When the cell storage section 17 a is closed, the cell cover 15 forms part of the rear face and part of an end face of the body 17 . A power supply connector 19 to be connected to the cell 13 and a mechanical switch 18 of a cell cover opening and closing detection apparatus are provided in the cell accommodation section 17 a. The switch 18 has an off state when the cell cover 15 is closed, but the switch 18 has an on state when the cell cover 15 is opened. Consequently, opening or closing of the cell cover 15 is detected. Further, the cell 13 is connected to the power supply connector 19 in order to supply operation power to the electronic circuit provided in the body 17 . Even if the cell cover 15 is opened, since the cell 13 is connected to the power supply connector 19 , the power supply is not disconnected at once. That is, in order to disconnect the power supply, it is necessary for the user to first remove the cell cover 15 from the body 17 and then cut the connection between the cell 13 and the power supply connector 19 . In the following, operation of the portable telephone apparatus is described with reference to FIGS. 1 and 2 . In a state wherein the cell cover 15 of FIG. 2 is closed, the switch 18 of the cell cover opening and closing detection apparatus is off and the cell cover opening/closing detection signal 3 to be supplied to the control circuit 5 of FIG. 1 has the High level. Meanwhile, if the cell cover 15 is opened, then the switch 18 is switched on, and the cell cover opening/closing detection signal 3 to be supplied to the control circuit 5 of FIG. 1 exhibits the Low level and the interruption signal 6 is transmitted from the control circuit 5 to the CPU 7 . The CPU 7 thus discriminates that the cell cover 15 is removed, and writes the data of the RAM 11 into the flash ROM 10 . Similarly, if the cell remaining power detection apparatus 2 detects a state wherein the amount of the cell 13 is little, then the cell remaining power detection signal 4 of the cell remaining power detection apparatus 2 is transmitted as the interruption signal 8 to the CPU 7 through the control circuit 5 . The CPU 7 discriminates that the cell remaining power is little and writes the data of the RAM 11 into the flash ROM 10 . A warning to the user when the cell remaining power is little is given, for example, by blink displaying a mark of a cell or emitting warning sound. Since such warning is well known to those skilled in the art, detailed description of the warning is omitted herein. A particular example the control circuit 5 is shown in FIG. 3 . Referring to FIG. 3 , the control circuit 5 includes four flip-flop circuits 20 , 21 , 23 , and 24 and two AND gates 22 and 25 . Each of the flip-flop circuits 20 , 21 , 23 , and 24 has an input terminal D to which data is inputted, a clock input terminal C to which a clock pulse is inputted, an output terminal Q, and an inverted output terminal /Q. The cell cover opening/closing detection signal 3 of the cell cover 15 is inputted to the input terminal D of the flip-flop circuit 20 , and the clock pulse is inputted to the clock input terminal C. An output of the output terminal Q of the flip-flop circuit 20 is inputted to the input terminal D of the flip-flop circuit 21 . An output signal 27 of the inverted output terminal /Q of the flip-flop circuit 20 and an output signal 26 of the output terminal Q of the flip-flop circuit 21 are inputted to the CPU 7 through the AND gate 22 . When the input signal to the control circuit 5 which is the opening/closing detection signal 3 regarding the cell cover 15 changes from the High level to the Low level, the control circuit 5 generates a High pulse. The pulse is inputted to the CPU 7 as the interruption signal 6 . Also the cell remaining power detection signal 4 is inputted to the control circuit 5 . The cell remaining power detection signal 4 is inputted to the input terminal D of the flip-flop circuit 23 of the control circuit 5 shown in FIG. 3 . The clock pulse is inputted to the clock terminal C of the flip-flop circuit 23 . An output signal of the output terminal Q of the flip-flop circuit 23 is inputted to the input terminal D of the flip-flop circuit 24 . An output signal 29 of the inverted output terminal /Q of the flip-flop circuit 23 and an output signal 28 of the output terminal Q of the flip-flop circuit 24 are inputted to the CPU 7 through the AND gate 25 . When the cell remaining power detection signal 4 changes from the High level to the Low level, the control circuit 5 generates a High pulse and transmits it as the interruption signal 8 to the CPU 7 . The CPU 7 breaks the process being performed at present in response to the interruption signal 6 or 8 inputted thereto and transfers only those data, which are necessary to be maintained, from the RAM 11 to flash ROM 10 . Upon transfer of the data, the data are read from the RAM 11 through the bus 12 and are written into the flash ROM 10 through the bus 12 . In this manner, the data of the RAM are written into and protected by the flash ROM 10 . While a preferred embodiment of the present invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. For example, while the portable telephone apparatus of the embodiment described above uses a mechanical switch as the cell cover opening/closing detection apparatus 1 , any other detection element may be used only if it produces a detection signal when the cell cover is opened or closed. For example, a magnet may be mounted at a predetermined position of the cell cover 15 such that opening or closing of the cell cover 15 is detected by means of a Hall element or a reed relay which cooperates with the magnet.

The invention provides a portable telephone apparatus wherein, when a necessary voltage is not obtained from a cell because the cell is removed or consumed, data can be backed up with a simple configuration and at a low cost. A cell is removably accommodated in a cell accommodation portion of the body of a portable telephone apparatus, and the cell accommodation portion is closed up with a cell cover. Opening or closing of the cell cover is detected by a switch serving as a cell cover opening/closing detection apparatus in the body, and is outputted as an interrupt signal to a CPU through a control circuit. When the remaining power of the cell becomes little, a cell remaining power detection signal is outputted as another interrupt signal to the CPU through the control circuit. In response to either interrupt signal, stored data of a RAM are transferred to and protected by a flash ROM.

CROSS-REFERENCE TO A RELATED APPLICATION This application claims priority of German Patent Application Number 10 2008 064 570.2, filed on Dec. 19, 2008. BACKGROUND The invention relates to a device for controlling the movement of a both motorically and manually movable vehicle part and a method for controlling the movement of a both motorically and manually movable vehicle part. Such a device comprises a drive unit being controllable in its rotational speed for motorically moving the vehicle part, a coupling device for coupling the drive unit to the vehicle part, and a control unit. The control unit controls the drive unit and the coupling device such that, when manually moving the vehicle part, the drive unit is coupled via the coupling device to the vehicle part if the vehicle part has reached a predefined position. To prevent the manually moved vehicle part—for example a vehicle door, a rear door, a sliding door or the like—hitting an end stop during an opening movement it is known to connect the moved vehicle part, for example the vehicle door, via a coupling device with a motoric drive unit within a drive train and to decelerate the vehicle part via the drive train. In dependence of the door speed, herein, the coupling is adjusted and a defined braking torque is generated to reduce the moving speed of the vehicle part before reaching the maximally opened position and to dampen the hitting of the vehicle part on the end stop. The coupling device is, for example, constituted as an electromagnetic coupling of the type of a disc brake. Herein, because of the slippage of the coupling device occurring within the coupling device usually an abrasion occurs, which makes a service of the coupling device in regular intervals necessary and has an influence on the system characteristics of the coupling device over its live span. The coupling device can furthermore be used to fixedly hold the vehicle part, namely to hold it in its opened position. An electromagnetic coupling device herein comprises the disadvantage that for maintaining the coupling a permanent current supply is necessary such that the current supply system of the vehicle is continuously strained and a vehicle battery is emptied when the vehicle door is opened and held fixedly. From WO 2007/071641 A1 a device and a method for controlling the closing movement of a manually movable vehicle part is known, in which the vehicle part during the closing movement, starting from the opened position, passes a first adjustment region in which the vehicle part is moved without engagement of a separate control means towards a closed position and subsequently passes a second adjustment region in which the closing movement of the vehicle part is controlled through the control means. The closing movement of the vehicle part, thus, only in the beginning is free and uncontrolled, whereas in the second adjustment region when approaching the closed position the closing movement of the vehicle part occurs in a guided manner such that an uncontrolled slam-shut of the vehicle part, for example a vehicle door, is prevented. SUMMARY It is an object of the invention to provide a device and a method which in an easy and low-wear manner allow for controlling the movement of a both motorically and manually movable vehicle part. Herein, it is provided that the control unit, for the coupling, controls the rotational speed of the drive unit in dependence on the moving speed of the vehicle part. In particular, by means of the control unit the rotational speed of the drive unit can be adjusted such that the rotational speed of the drive unit is adapted to the moving speed of the vehicle part. Thereby, it becomes possible to use a coupling device of the type of a clutch coupling in which the coupling is achieved in a positive locking or forced locking manner without slippage. With a positive locking coupling of the drive unit with the vehicle part, embodiments of a coupling device for example can be used in which the gearing parts to be coupled, for example gearing wheels, are brought into engagement in a positive locking manner and thereby achieve the coupling. The coupling device thereby works essentially without slippage such that a wear by abrasion is essentially avoided. For achieving a force locking coupling, for example an electromagnetic coupling device can be used in which, via a coil, a magnetically soft material is altered in its magnetization and, because of the altering of the magnetization, the force locking coupling is achieved. If the electromagnetic coupling device is energized, the parts to be coupled (for example constituted as coupling discs) are, due to static friction, brought into a force locking engagement. Because of the adjusted speed of the drive unit and the vehicle part, the coupling can be established abruptly and, thus, essentially without slippage and does not have to be built up slowly. To be able to use a coupling device for providing an essentially slippage-free coupling, the drive unit is adapted in its rotational speed to the moving speed of the vehicle part, for example a vehicle door, prior to establishing the coupling. The drive unit, hence, prior to establishing the coupling is synchronized with the moving speed of the vehicle part, i.e. it is brought already in its idle time into a rotational speed which allows coupling the drive unit with the vehicle part without slippage. The parts to be coupled, hence, move with the same speed prior to establishing the coupling such that they can be brought into engagement with each other in a slippage-free manner and then couple the drive unit in a force locking or positive locking manner with the vehicle part. If the drive unit is engaged with the vehicle part, the movement of the vehicle part can be controlled, in particular decelerated by suitably controlling the drive unit in order to dampen the hitting of an end stop when opening the vehicle part or to prevent an uncontrolled slam-shut when closing the vehicle part. The device can for example comprise a rotational speed sensor for detecting the rotational speed of the drive unit and a position and speed sensor for detecting the position and/or the speed of the vehicle part. Via the rotational speed sensor the rotational speed of the drive unit is detected and is adjusted to the moving speed of the vehicle part being measured through the position and speed sensor such that a coupling of the drive unit with the vehicle part becomes possible. The coupling device advantageously comprises three coupling states. In a first coupling state the drive unit is decoupled from the vehicle part such that the vehicle part, for example a vehicle door, can be manually moved independently from the drive unit. This coupling state is also referred to as “non-energized open”. In a second coupling state the drive unit is coupled with the vehicle part, the coupling device hence is in a coupling engagement and is energized herein for the actuation. This second coupling state, which ensures a maximum engagement of the coupling device, is adopted by the coupling device when motorically moving the vehicle part. A manual movement of the vehicle part independent from the drive unit is not possible. This coupling state is also referred to as “energized closed”. In a third coupling state the drive unit is coupled with the vehicle part. Herein, the coupling device however is not energized for actuation such that the coupling device connects the drive unit in a coupling manner with the vehicle part, at the same time however does not consume power. This third coupling state, also referred to as “non-energized holding”, can for example be used for fixedly holding the vehicle part in an opened position, wherein by the non-energized holding of the coupling without power consumption the supply system of the vehicle is not strained. The device in particular is constituted for providing an end stop damping when moving the vehicle part into an opened position. If, for example, a vehicle door is manually moved from a closed position into an opened position, the coupling device, controlled by the control unit, establishes a coupling of the drive unit with the vehicle part as soon as the vehicle part has reached a predefined position—for example a vehicle door has reached a predefined opening angle. After passing the predefined position, hence, the opening movement of the vehicle part is no longer free, but is guided by the drive unit coupled with the vehicle part and is decelerated by reducing the rotational speed of the drive unit. Via the drive unit, thus, the vehicle part can be transferred into a standstill without the vehicle part hitting an end stop. If the standstill is reached, the vehicle part can be fixedly held in the opened position in that the coupling device—according to the third coupling state described above—couples the drive unit in a non-energized manner with the vehicle part. In addition or alternatively, the device can be constituted to provide a slam-shut prevention when moving the vehicle part into a closed position. The device, hence, not only controls the opening of the vehicle part, but also the closing in that the coupling device, prior to reaching the closed position, couples the drive unit with the vehicle part and by controlling the rotational speed of the drive unit controls the movement of the vehicle part. In particular, the vehicle part can in this way, by controlling the drive unit, be decelerated down to a predefined nominal speed in order to be transferred in a controlled and guided manner into the closed position. The objective furthermore is achieved through a method for controlling the movement of a both motorically and manually movable vehicle part using a device comprising a drive unit controllable in its rotational speed for motorically moving the vehicle part, a coupling device for coupling the drive unit with the vehicle part and a control unit for controlling the drive unit and the coupling device. When manually moving the vehicle part, the drive unit herein is coupled via the coupling device with the vehicle part if the vehicle part has reached a pre-defined position. In addition, it is provided that for the coupling the rotational speed of the drive unit is adapted to the moving speed of the vehicle part. It herein is the idea, for the coupling of the drive unit with the vehicle part, to adjust the rotational speed of the drive unit prior to the coupling, i.e. already in the idle state, to the moving speed of the vehicle part, i.e. to synchronize it with the movement of the vehicle part such that a slippage-free, force locking or positive locking coupling of the drive unit with the vehicle part can be established. The coupling is established when the vehicle part has reached a pre-defined position, for example a vehicle door has passed a predefined critical opening angle. After coupling the vehicle part with the drive unit the movement of the vehicle part then takes place in a guided manner and can, by controlling the drive unit, be controlled, in particular be decelerated. The pre-defined position, at the reaching of which the coupling is established, can be previously defined and set. However, it is advantageous to individually determine the pre-defined position, for example a critical opening angle of a vehicle door, in dependence on the movement of the vehicle part, in particular in dependence on its moving speed. The basis for this is that the required braking path, for example of a vehicle door, critically depends on the moving speed of the vehicle door. If for example a vehicle door is opened and if the vehicle door shall be prevented hitting an end stop, a comparatively small braking path is required at a small moving speed of the vehicle door, however a large braking path prior to reaching the end stop is required at a large moving speed. Accordingly, the critical opening angle is determined and set, wherein the critical opening angle is determined from the difference of the desired opening angle, i.e. for example the end position of the vehicle door, and the required braking angle. The estimation of the braking angle can for example be carried out assuming a linear dependence between the actual angular speed of the vehicle door and the braking path of the vehicle door. If the critical opening angle set according to the moving speed of the vehicle door is reached, the coupling of the drive unit with the vehicle door is established and, subsequently, the drive unit is controlled for guiding the movement of the vehicle door. If the pre-defined position, for example the critical opening angle of the vehicle door, thus is reached, the coupling device is energized and thereby actuated for establishing the coupling of the drive unit with the vehicle part. From the first coupling state described above, the coupling device thereby is brought into the second coupling state. To influence the movement of the vehicle part in the desired manner after establishing the coupling, the rotational speed of the drive unit is controlled. Herein, it in particular can be provided to reduce the rotational speed of the drive unit for decelerating the vehicle part in order to avoid a hard hit of an end stop when opening the vehicle part or when closing the vehicle part. To maintain the coupling of the drive unit with the vehicle part in a secure and reliable manner during the movement of the vehicle part the coupling device is energized during the movement of the vehicle part and, hence, is held in the second coupling state. For providing an end stop damping when moving the vehicle part into an opened position it preferably is provided that the drive unit decelerates the vehicle part to a standstill. After reaching the standstill, the coupling device can then maintain the coupling and in this way fixedly hold the vehicle part, wherein the coupling device is not energized, hence does not consume any power and does not strain the electric supply system of the vehicle. This state of the coupling device, previously described as third coupling state, is also referred to as “non-energized holding”, wherein the coupling provided by means of the coupling device preferably is constituted such that the vehicle part is securely fixed, but is released in case of a manual force applied to the vehicle part such that the vehicle part can be moved manually in a free fashion without huge effort. In addition or alternatively to the end stop damping also a slam-shut prevention when moving the vehicle part into a closed position can be provided, in the context of which the drive unit decelerates the vehicle part into a predefined moving speed when closing the vehicle part. The moving of the vehicle part into the closed position can then take place, in a final phase, in a motorically guided manner through the drive unit coupled with the vehicle part, wherein the drive unit pulls the vehicle part motorically into a closed position, for example a pre-engagement position of a vehicle door. In this final phase, then, the movement of the vehicle part in addition must be monitored for providing a jam protection and must be controlled to avoid, in this motorically controlled final phase, a jamming of an object between the closing vehicle part and the vehicle body. BRIEF DESCRIPTION OF THE DRAWINGS The idea underlying the invention shall subsequently be explained in detail according to the embodiments shown in the figures. Herein, FIG. 1 shows a schematic view of a vehicle with a vehicle door to be moved; FIG. 2 shows a schematic view of a vehicle door acting together with a device for controlling the movement; FIG. 3 shows a schematic flow diagram for controlling the opening movement of the vehicle door; FIG. 4 shows a schematic flow diagram for controlling the closing movement of a vehicle door and FIG. 5 shows a graphic view of the energization of a coupling device for transferring the coupling device into different coupling states. DETAILED DESCRIPTION FIG. 1 shows in a schematic overview a vehicle 1 with a side vehicle door 10 constituting a vehicle part to be moved, wherein the vehicle door 10 , for opening, can be moved in a moving direction B OPEN and for closing in an opposite moving direction B CLOSE . In the closed position the vehicle door 10 closes a side opening in the vehicle body, whereas in a maximally opened position the vehicle door 10 has a maximum opening angle α max which for example can amount to about 75°. The vehicle door 10 can be moved both motorically and manually and is for this, as shown in FIG. 2 , via a coupling device 21 connected to a drive unit 2 . The drive unit 2 , comprising for example an electric motor and a gearing, is controlled via a control unit 3 , wherein the control unit 3 can take over both the control of the drive unit 2 , the control of the coupling device 21 and for example the control for providing a jam protection. The control unit 3 , for this purpose, is connected with a rotational speed sensor 31 for measuring the rotational speed of the drive unit 2 and with a position and speed sensor 32 for measuring the position and/or the moving speed of the vehicle door 10 . The rotational speed sensor 31 can for example be constituted as a Hall sensor which detects the number of rotations of a drive shaft of the drive unit 2 . The device schematically shown in FIG. 2 , comprising the drive unit 2 , the control unit 3 and the coupling device 21 , serves on the one hand for motorically adjusting the vehicle door 10 . For this, the drive unit 2 is connected via the coupling device 21 to the vehicle door 10 such that the drive unit 2 can apply a torque to the vehicle door 10 and can move the latter for opening or closing. Via the drive unit 2 , the control unit 3 and the coupling device 21 , on the other hand, a movement of the vehicle door 10 manually initiated by a user can be controlled and influenced. In particular, via the drive unit 2 , an end stop damping for preventing the vehicle door 10 from hitting an end stop when opening the vehicle door 10 and a slam-shut prevention for avoiding an uncontrolled slam-shut of the vehicle door 10 when closing can be provided. The coupling device 21 preferably is constituted such that it establishes a force locking or positive locking coupling of the drive unit 2 with the vehicle door 10 according to the type of a clutch coupling in that the components to be coupled are brought into engagement with each other in an abrupt and slippage-free manner. With a positive locking coupling, hence, for example respective gearing parts, for example gearing wheels, are brought into engagement in a positive locking manner. With a force locking coupling, for example an electromagnetic coupling device can be used which brings, through altering the magnetization of one or more coupling parts, the components to be coupled into a force locking engagement due to static friction in an essentially slippage-free manner. The coupling device 21 can assume at least three coupling states, wherein in a first coupling state the drive unit 2 and the vehicle door 10 are decoupled, i.e. the coupling is opened such that the drive unit 2 and the vehicle door 10 are not in engagement with each other, in a second coupling state the drive unit 2 is coupled with the vehicle part 10 and herein the coupling device 21 is energized for the actuation, in a third coupling state the drive unit 2 is coupled with the vehicle part 10 , wherein the coupling device 21 however is not energized for the actuation. In the second and third coupling state the drive unit 2 therefore is connected, via the coupling device 21 , with the vehicle door 10 . The second and third coupling state herein differ in that in the second coupling state the coupling device 21 is energized, i.e. it consumes power, to establish the coupling between the drive unit 2 and the vehicle door 10 with a maximum engagement. In the third coupling state, in contrast, the coupling device 21 is not energized such that the coupling device 21 does not consume power. The second coupling state serves for the motoric adjustment of the vehicle door 10 , whereas the third coupling state in particular is assumed for fixedly holding the vehicle door 10 , i.e. for holding the vehicle door 10 in an opened position. If the vehicle door 10 is manually moved from a fixed position, the third coupling state can be released and the drive unit 2 can be decoupled from the vehicle door 10 to allow a free and unhindered movement of the vehicle door 10 by a user. In FIG. 3 a method 100 for providing an end stop damping when opening the vehicle door 10 is schematically illustrated. First, the vehicle door 10 is in a closed or not fully opened position from which in step 101 a manual door opening procedure is started. The coupling device 21 in the beginning is decoupled and, hence, open. Starting from this step 101 it is checked in step 102 whether the opening angle α of the vehicle door 10 is larger than a critical opening angle α crit (see FIG. 1 ). This critical opening angle α crit depends on the moving speed of the vehicle door 10 and is determined according to the moving speed of the vehicle door 10 on a case-to-case basis. The critical opening angle α crit herein is determined from the required braking path of the vehicle door 10 and is determined from the difference of the desired opening angle, corresponding to a maximum opening angle α max , and the required braking angle which is estimated assuming a linear dependence between the angular speed of the vehicle door 10 and the braking path of the vehicle door 10 . If the opening angle α of the vehicle door 10 exceeds the critical opening angle α crit , an adjustment of the rotational speed takes place during which the rotational speed of the drive unit 2 is adjusted to the moving speed of the vehicle door 10 (step 103 ). Herein the coupling device 21 is in the first coupling state, i.e. it is open and not energized. For controlling the rotational speed of the drive unit 2 the motor voltage applied to the motor is increased until the rotational speed of the drive unit 2 is adjusted to the moving speed of the vehicle door 10 . The rotational speed of the drive unit 2 is detected via a rotational speed sensor 31 (see FIG. 2 ), whereas the position and speed sensor 32 measures the moving speed (angular speed) of the vehicle door 10 . If the rotational speed sensor 31 is formed as a Hall sensor, the angular speed ω of the drive shaft of the drive unit 2 results from the number of the received Hall signals n Hall per rotation of the drive shaft and the period signal of the motor T to be ω=2π/( T·n Hall ). From this, by division through the transmission ratio between drive unit 2 and vehicle door 10 , it is computed which angular speed of the vehicle door 10 this would correspond to. If the angular speed thus computed is larger or equal to the angular speed of the vehicle door measured through the position and speed sensor 32 , it is assumed that the adjustment of the rotational speed has been achieved, i.e. the rotational speed of the drive unit 2 is adjusted to the moving speed of the vehicle door 10 . In step 104 it is checked whether the adjustment of the rotational speed has taken place and whether a maximum motor voltage has been reached, i.e. the rotational speed of the drive unit 2 cannot be increased further. If the adjustment of the rotational speed has taken place in step 105 , the coupling between the drive unit 2 and the vehicle door 10 is established in that the coupling device 21 is transferred into the second coupling state in which the coupling device 21 is energized and the drive unit 2 is coupled with the vehicle door 10 . At the same time, the motor voltage applied to the drive unit is kept constant, i.e. the rotational speed of the drive unit 2 is at this time not changed. For a minimum duration the motor voltage is kept constant (step 106 ). To decelerate the vehicle door 10 before reaching the maximum opening angle α max and to avoid the vehicle door 10 hitting the end stop in step 107 the motor voltage is linearly decreased and thereby the rotational speed of the drive unit 2 is reduced. Due to the coupling of the drive unit 2 with the vehicle door 10 thereby also the vehicle door 10 is decelerated in a controlled manner. In step 108 it is checked whether a standstill of the vehicle door 10 is reached or the vehicle door 10 has reached the maximum opening angle α max . The vehicle door 10 hereby is assumed to stand still if the amount of the measured moving speed (angular speed) of the vehicle door 10 for a pre-determined time falls below a pre-defined (small) value. If the standstill of the vehicle door 10 is reached, in step 109 the vehicle door 10 is fixedly held and for this the coupling device 21 is transferred into the third coupling state in which the coupling device 21 is not energized, however the coupling is maintained. In addition, during the method 100 it is continuously checked whether the door opening angle α is smaller than when starting the opening movement in step 101 . This indicates an intervention of a user and a counteraction for ending the opening movement (a pull back of the vehicle door 10 ). Accordingly, the method 100 for the opening is stopped and a method for closing the vehicle door 10 is initiated. To prevent an uncontrolled slam-shut when closing the vehicle door 10 the movement of the vehicle door 10 can be controlled via the drive unit 2 also during the closing. A method 200 of this kind is schematically shown in FIG. 4 . Here, it is started from a state in which the vehicle door 10 shall be closed from a fully or partially opened position. The closing is initiated manually (step 201 ), wherein the coupling device 21 is in the first coupling state and, thus, is non-energized and open. No motor voltage is applied to the drive unit 2 . First, after the manual initiation of the closing movement in step 202 it is checked whether the door opening angle α is smaller than a critical opening angle α crit and at the same time the vehicle door 10 is moved with a predefined minimum speed. The critical opening angle α crit again is determined individually and on a case-to-case basis according to the moving speed of the vehicle door 10 , depends on the required braking path of the vehicle door 10 and in general differs from the critical opening angle α crit for providing the end stop damping when opening the vehicle door 10 . The reason for checking whether the vehicle door 10 moves faster than a predefined minimum speed is explained by the fact that a slam-shut prevention is not necessary if the vehicle door 10 moves slowly. If the door opening angle α is smaller than a critical opening angle α crit and if the vehicle door 10 moves with a moving speed larger or equal to the minimum speed, in step 203 , at first, an adjustment of the rotational speed takes place during which a linearly increasing motor voltage is applied to the drive unit 2 and thereby the rotational speed of the drive unit 2 is adjusted to the moving speed of the vehicle door 10 . The coupling device 21 herein is in the first coupling state, i.e. it is open and not energized. In step 204 it is checked whether the adjustment of the rotational speed has taken place or, possibly, the maximum motor voltage and, thus, the maximum rotational speed of the drive unit 2 has been reached. If the adjustment of the rotational speed has taken place, in step 205 the coupling of the drive unit 2 with the vehicle door 10 is established. The motor voltage and, hence, the rotational speed of the drive unit 2 are kept constant for a minimum duration (step 206 ). In step 207 the motor voltage applied to the drive unit 2 is reduced and thereby the rotational speed of the drive unit 2 is decreased such that the vehicle door 10 coupled with the drive unit 2 is decelerated. The motor voltage herein is reduced to a predefined value which corresponds to a predefined moving speed of the vehicle door 10 . In contrast to the end stop damping, hence, the vehicle door 10 is not decelerated into a standstill, but only is transferred into a reduced, pre-defined moving speed. In step 208 the vehicle door 10 is moved for a given time with a pre-defined reduced moving speed and in step 209 is transferred motorically into a closed state, corresponding for example to a pre-engagement position of the vehicle door 10 . The motor voltage herein is adjusted according to a characteristic diagram which is adapted in a suitable manner for closing the vehicle door 10 . The actuation of the coupling device 21 for the transfer into the different coupling states by applying a voltage U is shown by way of example in FIG. 5 as a function of time t. At first, the coupling device 21 is in a first coupling state Z 1 in which the voltage U applied to the coupling device 21 has an amount of 0 Volt and the coupling device 21 is decoupled. This coupling state Z 1 is also referred to as “non-energized open”. If a positive voltage U of for example 12V is applied to the coupling device 21 , the coupling device 21 is transferred into a second coupling state Z 2 in which the coupling device 21 is actuated and the drive unit 2 is coupled with the vehicle door 10 . The coupling device 21 is in this state Z 2 to motorically move the vehicle door 10 . If subsequently a voltage U of 0 Volt is applied, the coupling device 21 reaches a third coupling state Z 3 in which the coupling device 21 couples the drive unit 2 with the vehicle door 10 , herein however is not energized and, hence, does not consume power. This coupling state Z 3 is referred to as “non-energized holding”. In the third coupling state Z 3 the vehicle door 10 can, via the engagement of the coupling device 21 , be fixedly held in an opened position without thereby straining the electric supply system of the vehicle. To transfer the coupling device 21 from the third coupling state Z 3 again into the first coupling state Z 1 a negative voltage U of for example −12 Volt is applied to the coupling device 21 for a short period of time, and thereby the coupling engagement of the coupling device 21 is released. In the first coupling state Z 1 the drive unit 2 is separated from the vehicle door 10 such that the vehicle door 10 can be moved freely and independently from the drive unit 2 in a manual fashion. It is also possible to apply a negative voltage pulse immediately after the second coupling state Z 2 such that the coupling device 21 from the second coupling state Z 2 directly transfers back into the first coupling state Z 1 . Via the drive unit 2 the vehicle door 10 can also be moved in a completely motoric fashion. For this, the coupling device 21 establishes a coupling of the drive unit 2 with the vehicle door 10 such that the drive unit 2 is in engagement with the vehicle door 10 and can transfer a torque onto the vehicle door 10 . As illustrated in FIG. 1 the opening path of the vehicle door 10 is divided into different angular regions. In a first angular region between α=0° and α=α fix (for example11°) the vehicle door 10 is not held if an opening movement is interrupted, i.e. the vehicle door 10 is not fixedly held, and the coupling device 21 moves into the first coupling state in which the drive unit 2 and the vehicle door 10 are decoupled. If the movement of the vehicle door 10 , in contrast, is interrupted within the angular region between α=α fix and α=α max (so called fixing region) the vehicle door 10 is fixedly held. The coupling device 21 for this is brought into the third coupling state in which the coupling device 21 is not energized, however the coupling between the drive unit 2 and the vehicle door 10 is maintained. Via the drive unit 2 , hence, the vehicle door 10 is held in the respectively reached position and is fixed such that an unwanted movement of the vehicle door 10 is prevented. If the vehicle door 10 being fixedly held within the fixing region is manually moved from the fixedly held position, the coupling device 21 again is transferred into the first coupling state in which the drive unit 2 and the vehicle door 10 are decoupled such that a user can freely and without large effort move the vehicle door 10 . If the vehicle door 10 within the fixing region, when manually moving the vehicle door 10 , falls below a pre-defined angular speed for a pre-defined time, this is interpreted as a holding command by the user and the coupling device 21 is transferred via the second coupling state into the third coupling state in which the vehicle door 10 is fixedly held. In an angular region between α=α jam (for example15°) and α=0 (corresponding to the closed position) in addition a jam protection is provided which is always active if the vehicle door 10 is closed motorically, i.e. during the (automatic) electric closing. During a manual closing by a user the jam protection is not active. In combination with a slam-shut prevention however also during the manual closing it is transferred into the state of the automatic, electric closing after decelerating the vehicle door 10 and, hence, into a motorically controlled movement (steps 205 and the following according to FIG. 4 ) during which the jam protection is active. The active region of the jam protection is freely definable. The boundary angle for the jam protection α jam , herein, may also be larger than 15°. At a door opening angle α>α jam no active jam protection takes place. However, also in this angular region a blocking detection is performed in the context of which it is monitored whether the movement of the vehicle door 10 is blocked and the moving procedure should be interrupted by means of an overload switch-off. The required forces until the termination of the door movement are larger than for a jam protection, and no reversing of the vehicle door 10 is carried out, but the coupling device 21 is only decoupled. Background of this is that for example at an inclined position of the vehicle 1 a larger load of the drive train can occur such that the initiation of the blocking detection is to be set in an accordingly robust manner to avoid a false initiation. The initiation threshold of the blocking detection is freely settable. A blocking state is detected if the initiation threshold is exceeded for a pre-defined time. Thereupon the motor is switched off and the coupling is decoupled. In the angular region between α=α jam and α=0 (jam protection region) an active jam protection takes place. The vehicle door shortly before entering into the jam protection region is brought into a pre-defined, constantly reduced angular speed or into a variably reduced angular speed using a stored angle dependent characteristic diagram. Thereby, on the one hand the detection of a jamming situation is made easier and on the other hand the jamming force occurring during a jamming situation are reduced because of the reduced moving speed of the vehicle door 10 . In addition, because of the lower moving speed of the vehicle door 10 it can be reversed faster, because the vehicle door 10 does not have to be decelerated and reversed from a large, but only from a pre-defined small moving speed. The detection of a jamming situation can for example be performed by analysing the angular speed of the vehicle door 10 or the rotational speed of the drive unit 2 . Conceivable, in addition, are directly detecting, contactless or contacting sensors, for example capacitive sensors or touch sensors which directly monitor the space in reach of the vehicle door 10 . During the automatic and manual electrical closing the starting angle of the vehicle door 10 is stored. The reversing of the vehicle door 10 , when detecting a jamming, then is performed by a pre-defined angle, however at maximum until the stored starting angle. Background of this is that it shall be prevented that the vehicle door 10 hits an object standing next to the vehicle 1 , for example an adjacent vehicle on a parking lot, during the reversing. A reversing beyond the starting angle, thus, is not possible such that the vehicle door 10 during the reversing is not opened further than the starting angle at the initiation of the closing movement and, hence, the hitting of an adjacent object is not possible. Shortly before reaching the starting angle or the maximum door opening angle the vehicle door 10 is linearly decelerated into a standstill such that a harmonic movement results. The idea underlying the invention is not limited to the embodiments described above, but can also be realized within completely different embodiments. In particular, the described method and the described device can also be applied at other vehicle parts than a vehicle door, for example at a rear door, a sliding side door or a sun roof. Advantageously, herein the end stop damping and the slam-shut prevention are combined with each other, but can also be used separately from each other in that at a vehicle part for example only an end stop damping, but no slam-shut prevention, or vice versa are used.

A device for controlling the movement of a both motorically and manually movable vehicle part includes a drive unit controllable in its rotational speed for motorically moving the vehicle part, a coupling device for coupling the drive unit with the vehicle part, and a control unit which controls the drive unit and the coupling device such that during manually moving the vehicle part the coupling device couples the drive unit with the vehicle part if the vehicle part has reached a pre-defined position. The control unit controls the rotational speed of the drive unit depending on the moving speed of the vehicle part. In this way, a device and a method are provided which in an easy and low-wear manner allow for a control of the movement of a both motorically and manually movable vehicle part.

CROSS-REFERENCE TO RELATED APPLICATION This application is a division of application Ser. No. 498,768 filed Mar. 26, 1990 allowed. BACKGROUND OF INVENTION A process to touch up painting flaws is known in which, after polishing, the flawed site is surrounded by a foam ring and the area delimited by the ring is cooled down to a temperature of approximately minus 40° C. (minus 40° F.) by means of gaseous nitrogen having a temperature of approximately minus 160° C. (minus 256° F.) After this temperature has been reached, the polishing operation is started. As soon as the cooled site has warmed up to a temperature of approximately minus 10° C. (14° F.), the polishing operation is discontinued and the site is cooled down once again. In order to improve this discontinuous process, the suggestion has been made to carry out the cooling down and the polishing operations simultaneously However, no statements are made as to how this could be accomplished. This discontinuous process has the disadvantage that it is time-consuming and expensive with respect to the necessary equipment. A ring is needed to isolate the flawed site, several cooling phases are necessary and the polishing disk has to be taken out of the ring in order to apply the polishing agent. SUMMARY OF INVENTION The object of the invention is to create a device which is easy to handle and with which it is possible to work in a continuous manner. This object is attained according to the invention as follows. In order to process the work piece, for example, to polish a flawed site of a painted work piece, such as the body of car, it is necessary to maintain a certain temperature at the site where the work is to be performed in order to prevent the paint from becoming soft. Measurement of this temperature at the site where the work is to be performed can only be achieved by very complex means. Surprisingly, it has been found that the temperature of the cold gas as it enters the inlet of the tool is a good indicator of the temperature at the site on the work piece where the work is to be performed. One explanation for this is that the temperature at the site where the work is to be performed remains constant when the flow of cold gas is constantly and uniformly distributed over the entire are of the polishing disk where the work is to be performed, and when there is a constant and sufficient cooling supply. In this manner, it is possible to ascertain the amount of cooling per time unit necessary for a certain job or type of work and to provide this cooling by appropriately dosing the flow of cold gas. In addition to polishing painted or otherwise coated work pieces made of metal, plastics or wood, the invention can also be employed to polish other surfaces. Besides being dependent on the temperature, the cooling supply also depends on the pressure of the cold-gas flow which determines the amount of gas. For this purpose, according to the invention, a pressure sensor is installed in the flow path of the cold gas before the after-heating unit. According to the invention, the temperature at the inlet of the cold-gas flow (operating temperature) which is needed to carry out the work and the necessary gas pressure are ascertained and set by means of a process control mechanism. This control mechanism regulates the performance of the tank evaporation and of the after-heating unit as a function of the ascertained temperature and pressure values. Regulation of these values leads to economical consumption of cold gas. In order to prevent the temperature from exceeding or falling below the set value, according to another proposal of the invention, an additional temperature sensor is installed in the flow path of the cold gas beyond the after-heating unit. In order to operate the tool, it is important to cool it down to the necessary operating temperature before starting the work. Moreover, a stand-by temperature can be selected, which is then set by the control mechanism after a given time. This stand-by temperature is not sufficient for the polishing operation. It serves to keep the tool cold during interruptions in the work by means of a smaller amount of gas and/or of a higher cold-gas temperature for purposes of quickly re-establishing the operating temperature. In order to ensure that the work is not started before the operating temperature has been reached, for example, when a tool operated with compressed air is used, according to the invention it is suggested that a pressure-differential sensor be installed in the compressed-air supply line. This regulator has the function of closing the influx of air by means of a solenoid valve when the tool is turned on and the operating temperature has not been reached, so that the pressurized-air motor cannot run. It is also possible to use tools with an electric motor. There is an optical display for purposes of showing the set operating temperature. Likewise, there are also optical displays which show the stand-by temperature and the lowering of the operating temperature. It was also surprisingly found that when cold gas is fed to the moving tool, at the working sit between the tool and the site where the work is to be performed, a good distribution of the cold gas is achieved with simultaneous cooling of the tool and work piece. This cooling makes it possible to immediately work without the need for pre-cooling or else intermediate cooling, as shown by experiments. An advantageous approach to the cold-gas feed consists of carrying out the feed through the drive shaft of the tool, for example, through a borehole in the center of the tool. The invention relates to a processing device in which there is a relative movement between the tool and the work piece. This relative movement can consist of a rotation or of an oscillating motion, i which the tool is moved back and forth over the work piece. The invention can also be employed in the same manner for devices in which the tool remains stationary and the work piece carries out a relative movement with respect to the tool. A preferred embodiment of the invention encompasses the use in disk-shaped, rotating tools, and it is characterized by the arrangement of at least one opening to release the cold gas into the operating area of the tool. In an advantageous manner, several openings are arranged in the form of a circle. It is possible to achieve an especially good distribution of the cold gas in the operating area when the openings are oriented diagonally towards the outside. In an advantageous manner, the openings consist of boreholes which are easy to make. But the invention also encompasses an embodiment where the openings are in the form of slits. An especially good distribution of the cold gas is achieved when the openings are installed in the area of the hub of the rotating tool. In this context, an especially simple embodiment consists in arranging the openings in the element with which the tool is attached to the drive shaft. It is important that the deflection of the cold gas from the opening into the working area be carried out in such a way that the cold gas preferably encompasses the entire working area. The term cold gas used here refers to a cold air which has been cooled by suitable means to temperatures substantially lower than minus 20° C. (minus 4° F.). In an advantageous way, however, liquefied gas is employed such as, for instance, liquefied nitrogen having a boiling temperature of minus 196° C. (minus 320.8° F.) or else CO 2 having a boiling temperature of minus 79° C. (minus 110.2° F.). Although the use of other liquefied gases is also possible, this is expensive. The use of a mixture of liquefied gas and compressed air is advantageous, whereby the liquefied gas is sufficiently cold. The liquefied-gas tank is designed so as to be cold-insulated and it has a heating unit to evaporate the liquefied cold gas, and an after-heating unit at the outlet of the tank in the flow path of the cold gas. Before the inlet of the cold gas into the tool, there is a temperature sensor in the flow path of the cold gas. This temperature sensor is connected to a control mechanism which adapts the performance of the tank evaporation and/or of the after-heating unit, if the temperature changes at this site. This temperature value is an indicator of the operating temperature at the working area. Likewise, there is a pressure sensor at the outlet of the tank in the flow path of the cold gas, which is also connected to the control mechanism and which serves as an indicator of the amount of flowing cold gas. In order to save cold gas, according to the invention, there is a mixture tank between the liquefied-gas tank and the tool, to which cold gas and dry pressurized air are fed. Then, this mixture flows to the tool. By means of appropriately insulated lines, it is possible to attach several tools to a cold-gas tank or mixture tank. According to another embodiment of the invention, the supply of cold gas for one or more tools can be carried out by means of a mobile intermediate tank, which is replenished by a larger liquefied-gas storage tank. The tanks connected to the tools can e designed so as to be mobile, stationary or hanging (mobile or stationary). THE DRAWINGS FIG. 1 shows a polishing device for the invention above the work piece; FIG. 2 shows a section of the cold-gas feed of the device of FIG. 1; FIG. 3 shows a stationary device according to the invention; FIG. 4 shows the supply by means of a mobile intermediate tank; and FIG. 5 shows the control mechanism of the device. DETAILED DESCRIPTION The compressed-air motor 1 is equipped with an angular head 2, to whose drive shaft 3 a polishing disk 4 having a lambskin hood 5 is attached. This attachment is accomplished by a nut 6 that rests upon the hub 7. The cold-gas feed is done by means of an insulated tube 8 and by the angular head 2 in the follow shaft 3. From there, the cold gas reaches the working area of the polishing disk via the boreholes 9. The rotating lambskin hood 5 functions as a unilaterally open centrifugal pump due to the scooping effect and gas friction. As a result, gas is constantly conveyed out of the working area and replaced by new cold gas. Surprisingly, this effect leads to a permanent cooling of the polishing disk, thus making it possible to initiate the polishing operation immediately, without first cooling the work piece 10. The cooling effect is further promoted by positioning the polishing disk diagonally to the surface of the work piece 10 during polishing. As a result, the open centrifugal pump closely resembles a closed centrifugal pump with an intensified adhesion effect of the cold gas in the working area. In this manner, the surface to be polished and the entire polishing disk are constantly cooled. In this process, the cooling is completely sufficient and there is no need to interrupt the polishing operation in order to once again cool the work piece. Another advantage of the invention consists in soaking the polishing disk with polish. It is no longer necessary to cover the surface to be polished with polish although it does not rule out this option. When designing the processing tool, attention should be paid to ensure that the outflow rate of the cold gas is not higher than the suction effect of the rotating polishing disk. The stationary device according FIG. 3 consists of a liquefied-gas storage tank 11, from which there is an insulated line 12 leading to a mixture tank 13. There is a line 14 for dry compressed air connected to the mixture tank. An insulated pipeline system 15 leads from the mixture tank 13 to three small insulated tanks 34, which are connected to the processing tools 17 via insulated, flexible connecting tubes 16. The processing tools 17 can also be connected to a joint tank, depending on the conditions at the work place. It is also possible to connect several processing tools to one tank. In the case of the device according to FIG. 4, the supply for several tanks 21 comes from the main tank 11 via a mobile intermediate tank 18. This tank is filled ;via line 19, while emptying takes place via line 20. FIG. 5 depicts the control mechanism according to the invention. Reference number 22 designates a liquefied-gas tank equipped with a tank heating unit 23 and an after-heating unit 24. The cold gas flows via the connecting tube 25 to the processing tool 26. The tool 26 contains the pressurized air used to runt he motor via the lines 27 and 28. There is a temperature sensor 29 in the tube 25 before the inlet into the tool 26. This temperature sensor 29 is connected to the control mechanism input 29 via electrical lines not shown here. .There is another temperature sensor 30 in the flow path after the after-heating unit 24. There is a pressure sensor 31 before the after-heating unit 24. Both sensors are connected to the control mechanism inputs 30 and 31 via electrical lines not shown here. The pressure-differential regulator in the pressurized-air line 27 is designated by reference number 32, while the solenoid valve controlled by this regulator receives the reference number 33. The regulator 32 is connected to the control mechanism inputs 29 of the temperature sensor 29 via an electrical line.

A polishing device has a working area into which cold gas is fed continuously in order to cool the partial work-piece surfaces where work is to be performed to a temperature at which no changes occur to the work-piece surface except for polishing.

BACKGROUND OF THE INVENTION Ring hydrogenation of aromatic amines using Group 6 and Group 8 metals carried on a support is well known. Two aspects in the hydrogenation process are problematic. First, contaminants in the aromatic amine substrate can poison the catalyst thus impacting catalyst activity and catalyst life. Second, catalyst attrition can occur thereby resulting in catalyst loss and plugging of catalyst filtration equipment. Representative patents which illustrate various processes for the hydrogenation of aromatic amines are as follows: U.S. Pat. Nos. 2,606,925 and 2,606,927 disclose the hydrogenation of nitroaromatics and aromatic amines. The ′925 patent shows the use of ruthenium oxide as a catalyst whereas the ′927 discloses the use of cobalt on alumina. U.S. Pat. Nos. 3,636,108 and 3,697,449 disclose the hydrogenation of aromatic compounds and, particularly, 4,4-methylenedianiline to produce a product referred to as PACM, using an alkali metal-moderated ruthenium catalyst. Alkali moderation is accomplished by depositing a ruthenium compound on a support from an aqueous solution of sodium or potassium bicarbonate, hydroxide, or the like. A wide variety of carriers such as calcium carbonate, rare earth oxides, alumina, barium sulfate, kieselguhr and the like are shown as candidate supports. The ′449 patent discloses the in situ alkali moderation of the catalyst. U.S. Pat. No. 4,754,070 discloses an improved process for the hydrogenation of methylenedianiline contaminated with catalyst poisoning impurities. A catalyst comprised of rhodium and ruthenium was found to be effective in the hydrogenation of a crude methylenedianiline, i.e., one containing oligomers. Alkali moderation via addition of lithium hydroxide activation was shown to be effective for the combined catalyst. Carriers suited for the rhodium/ruthenium catalyst included alumina, carbonates, etc. U.S. Pat. No. 5,545,756 discloses a process for the hydrogenation of aromatic amines, whether mononuclear or polynuclear, using a catalyst of rhodium carried on a titania support. Examples of titania supports include TiA1 2 O 5 , TiSiO 4 and TiSrO 3 . The titania support permitted the use of rhodium alone as the active metal in the hydrogenation of crude methylenedianiline. Rhodium carried on titania in combination with ruthenium on alumina was also suited as a catalyst. Lithium hydroxide activation results in enhanced activity. BRIEF SUMMARY OF THE INVENTION This invention relates to an improvement in a process for the catalytic hydrogenation of aromatic amines and to the resultant catalyst. The basic process for hydrogenating both mononuclear and polynuclear aromatic amines comprises contacting an aromatic amine with hydrogen in the presence of a rhodium containing catalyst under conditions for effecting ring hydrogenation. The improvement in the ring hydrogenation process resides in the use of a catalyst comprised of rhodium carried on a lithium aluminate support. The following represents some of the advantages that can be obtained by the use of the catalysts under specified conditions, they are: an ability to achieve effective selectivity control to primary amine formation; an ability to reuse the catalyst over an extended period of time; an ability to be used in combination with alkali metal reaction promoters without adverse effects; an ability to tolerate some water through its low solubility in water; an ability to minimize catalyst loss and product contamination by virtue of excellent attrition resistance; and, an ability to achieve enhanced production through excellent reaction rates. DETAILED DESCRIPTION OF THE INVENTION The aromatic amines useful in the practice of the process can be bridged polynuclear aromatic amines or mononuclear aromatic amines. These can be substituted with various substituents such as aliphatic groups containing from 1-6 carbon atoms. Further, the amine group can be substituted with aliphatic groups such as alkyl or alkanol groups resulting in secondary and tertiary amine substituents. Representative mononuclear and polynuclear amines which may be hydrogenated are represented by the formulas: wherein R is hydrogen or C1-6 aliphatic, R 1 and R 2 are hydrogen, or C1-6 aliphatic, A is C1-4 alkyl, n is 0 or 1, x is 1-3 and y is 1-2 except the sum of the y groups in Formula I excluding A may be 1. When R is hydrogen, then the ring is unsubstituted. Examples of bridged aromatic amines include methylenedianilines such as bis(para-aminophenyl)methane (PACM) and bis(para-amino-2-methylphenyl)methane; toluidine; bis(diaminophenyl)methane; α, α′-bis(4-aminophenyl-para-diisopropyl benzene(bisaniline P), bis(diaminophenyl)propane (bisaniline A); biphenyl, N—C 1-4 -aliphatic derivatives and N,N′—C 1-4 aliphatic secondary and tertiary amine derivatives of the above bridged aromatic amines. Examples of mononuclear aromatic amines include 2,4- and 2,6-toluenediamine, aniline, butenyl-aniline derivatives; 1-methyl-3,5-diethyl-2,4 and 2,6-diaminobenzene (diethyltoluenediamine); monoisopropyltoluenediamine, diisopropyltoluenediamine, tert-butyl-2,4- and 2,6-toluenediamine, cyclopentyltoluenediamine, ortho-tolidine, ethyl toluidine, xylenediamine, mesitylenediamie, phenylenediamine and the N and N,N′—C1-4 aliphatic secondary and tertiary amine derivatives of the mononuclear aromatic monoamines and mononuclear aromatic diamines. Spinel LiAl 5 O 8 is the preferred support for the catalyst. It is a known composition and known as a support for some catalytic systems. The support is usually made by a solution method wherein an aqueous lithium salt is mixed as a solution with alumina followed by drying and calcination typically in air. Calcination is effected at temperatures in the range from 500 to 1500° C., preferably from about 700 to 1000° C. to ensure the LiAl 5 O 8 composition. Calcination typical requires at least 10 hours, generally from 20 to 25 hours. In formulating the lithium aluminum support, the level of lithium salt is controlled to provide an atomic ratio of lithium/aluminum ratio of from 0.2 to 1.5 to 5. The lithium aluminate support can also be made by a solid state reaction between a lithium salt and alumina. As with the solution method, the mixture is dried and then calcined at essentially the same high temperatures over extended periods of time. Lithium salts include LiCl, LiBr, LiF, Li 2 O, Li 2 SO 4 , LiNO 3 , LiOH, Li 2 CO 3 , CH 3 COOLi, HCOOLi with a preference given to Li 2 CO 3 , LiNO 3 , CH 3 COOLi. Source of alumina can be chi-alumina, gamma-alumina, eta-alumina, kappa-alumina, delta-alumina, Theta-alumina and alpha-alumina. For economic reasons, lower cost alumina precursors such as gibbsite, boehmite, bayerite, diaspore, can also be used. A rhodium salt is combined with the lithium aluminate support, based upon its weight as metal, in an amount sufficient to provide a ratio of about 0.1 to 25 weight parts rhodium per 100 weight parts of support. A preferred level is from 2 to 8 weight parts rhodium per 100 weight parts of support. With respect to the preferred catalyst, ruthenium is added to the catalyst with the rhodium to ruthenium weight ratio being from about 1 to 20:1, preferably 6 to 12 weight parts rhodium/weight part ruthenium on the support. Rhodium and ruthenium are added to the support by either incipient wetness or coprecipitation in the presence of a base in water, preferred bases are LiOH, Li 2 CO 3 , or Na 2 CO 3 . The catalyst comprised of rhodium and the lithium aluminate support is dried and heated to a temperature of <400° C. As with conventional processes the hydrogenation of aromatic amines using the present rhodium catalysts carried on a lithium aluminate support is carried out under liquid phase conditions. Liquid phase conditions are maintained typically by carrying out the hydrogenation in the presence of a solvent. Although as reported in the art, it is possible to effect reaction in the absence of a solvent, the processing usually is much simpler when a solvent is employed. Representative solvents suited for effecting hydrogenation of aromatic amines in the presence of the rhodium metal carried on a lithium aluminate support include saturated aliphatic and alicyclic hydrocarbons such as cyclohexane, hexane, and cyclooctane; low molecular weight alcohols, such as methanol, ethanol, isopropanol; and aliphatic and alicyclic hydrocarbon ethers, such as n-propyl ether, isopropyl ether, n-butyl ether, amyl ether, tetrahydrofuran, dioxane, and dicyclohexylether. Tetrahydrofuran is preferred. Although in some processes water can be used as a cosolvent, it is preferred that the system be maintained with less than 0.5% by weight. Water, when present in the system, tends to increase the amount of by-product alcohols and heavy condensation products during the hydrogenation process. Also, there is a tendency to deactivate the catalyst system in part by dissolving the support phase. An advantage of the lithium aluminate supported catalyst is that it tolerates the presence of water better than other supported catalysts, even when water content is up to 0.5% by weight. When a solvent is used, it can be used in concentrations as low as 50% by weight based upon the aromatic amine introduced into the reaction and typically the solvent is used at levels from about 75 to about 200% by weight of the starting compound. Under some circumstances solvent amount as high as 1000 to 2000% based upon the weight of aromatic amine are used. The hydrogenation of mononuclear and bridged anilines and aromatic amines employs hydrogen partial pressures which range from about 200 to 4000 psig. Preferably the pressure is no higher than 2500 psig and typically can be as low as from about 700 to 1500 psig. Lower pressures are preferred by reason of lower equipment and operating costs. When the pressure is raised toward the upper end of the operating range, higher reaction rates may be achieved but capital costs may override the enhanced productivity benefits. The ability to ring hydrogenate aromatic amines, and particularly crude methylenedianiline containing from 15 to 20% by weight oligomers, often referred to as MDA 85, at low hydrogenation partial pressures and to simultaneously obtain high conversion with excellent reaction rates and selectivity while minimizing loss to attrition, is achieved by the utilization of a specific catalyst system. Lithium aluminate as a support offers that ability to hydrogenate aromatic amines in the presence of contaminating oligomers as might appear in methylenedianiliine. In the past, to achieve high selectivity and minimize the formation of amine by-products, while maintaining activity it was proposed that the rhodium and ruthenium component, if present, be alkali moderated. However the lithium aluminate support apparently does not need significant alkali metal hydroxide moderation as do other supports, e.g., alumina and other mixed metal oxide supports. A limited amount of alkali metal hydroxide (preferred at 0.5% or below) may be employed for effective control of the hydrogenation selectivity. The following examples are intended to illustrate various embodiments of the invention and all parts and percentages given are weight parts or weight percents unless otherwise specified. EXAMPLE 1 Preparation Of Lithium Aluminate (LiAl 5 O 8 ) From Lithium Acetate Lithium acetate (CH 3 COOLi.2H 2 O, 40.0 g) was added to Gibbsite (C31 alumina 153 g) in a plastic container and mixed. The mixture was then transferred to a ceramic dish and dried at 110° C. for 24 h and calcined at 1000° C. in air for 20 h (ramp: 5° C./min). (Ramp refers to increasing the temperature from room temperature to the final temperature at a specified rate per minute.) Yield: ~ 100 g of white powder (XRD indicated LiAl 5 O 8 with purity over 98%.) EXAMPLE 2 Preparation Of Lithium Aluminate (LiAl 5 O 8 ) From Lithium Carbonate Lithium carbonate (Li 2 CO 3 , 14.5 g) was added to Gibbsite (C31 alumina from Alcoa, 153 g) in a plastic container and mixed well. The mixture is then transferred to a ceramic dish and calcined at 1000° C. in air for 24 h (ramp: 5° C./min). Yield: ~ 100 g of white powder (XRD indicated LiAl 5 O 8 with purity over 98%.) Synthesizing LiAl 5 O 8 by solid state reaction between a lithium salt and aluminum hydroxide eliminates the use of any solvents. This method is especially suitable for large scale synthesis. EXAMPLE 3 Preparation Of Lithium Aluminate (LiAl 5 O 8 ) From Lithium Hydroxide Lithium hydroxide (LiOH.H 2 O, 8.25 g) was added to Gibbsite (C31 alumina, 76.6 g) in 40 ml D.I. Water. The free-flow suspension was heated on a hot plate with stirring for 30 min to move water. The resulting solid cake was broken into small pieces and dried in a oven at 110° C. for 16 h. The solid was then ground and calcined at 600° C. (ramp: 5° C./min) for 20 h. Yield: 53 g white powder. EXAMPLE 4 Hot Water Wash Of LiAl 5 O 8 5.0 g of LiAl 5 O 8 from Example 1 was added to 100 ml of deionized (d.i.) water. The suspension was heated at 85° C. on a hot plate with stirring for 2 h. The remaining solid was collected by filtration and dried at 110° C. for 10 h. 4.8 g of LiAl 5 O 8 (identified by XRD) was recovered (96% recovery). EXAMPLE 5 Hot Water Wash Of LiAl 5 O 8 From Examples 1-3 5.0 g of LiAl 5 O 8 from Example 3 was added to 100 ml of d.i. water. The suspension was heated at 85° C. on a hot plate with stirring for 2 h. The remaining solid was collected by filtration and dried at 110° C. for 10 h. Only 3.4 g material was recovered (68% recovery). The results show that the sample of LiAl 5 O 8 calcined at 1000° C. (Examples 1 and 2) was much more water resistant than the LiAl 5 O 8 supported catalyst combined at a calcination temperature of 600° C. (Example 3) This is evidenced by the two water wash studies. Recovery of the solid after a hot water wash of LiAl 5 O 8 calcined at 1000° C. was 96%, compared to a recovery of 68% when it was calcined at 600° C. EXAMPLE 6 Preparation Of Rh(3%)/ LiAl 5 O 8 By Coprecipitation Method 7.50 g LiOH.H 2 O was added to 400 ml d.i. water (pH=13.2). 100 g LiAl 5 O 8 was then added to the solution with stirring (pH=13.2). 30.0 g Rh(NO 3 ) 3 solution (Rh wt. %=10.5%, HNO 3 , ~ 15%) was added to the LiAl 5 O 8 suspension dropwise with stirring. The color of the solution gradually changed from orange red to yellow. The pH is 12.5. The mixture was then heated on a hot plate to 80-85° C. for 30 min. The solution was colorless after heating and final pH is 11.5. The suspension was filtered. The yellow solid cake was collected and dried at 110° C. for 24 h and calcined at 380° C. in air for 6 h. Yield: ~ 102 g grayish black powder. EXAMPLE 7 Preparation Of Rh(3%)/LiAl 5 O 8 From Incipient Wetness Method 30.0 g Rh(NO 3 ) 3 solution (Rh wt. %=10.5%, HNO 3 , ~ 15%) was added to the LiAl 5 O 8 (100 g) dropwise with stirring. The resulting brownish yellow solid was dried at 110° C. for 24 h and calcined at 380° C. in air for 6 h. Yield: ~ 100 g grayish black powder. EXAMPLE 8 MDA Hydrogenation Comparisons General hydrogenation procedure: A 300 cc autoclave batch reactor was used for this work. All runs were conducted at 180° C. and an 850 psig hydrogen pressure. The solvent was THF. The methylenedianiline (MDA) feed was a 50/50 mixture of 97% MDA and THF. All hydrogenation reactions were carried out at a 1500 rpm stirring rate to minimize hydrogen mass transfer limitations. In the process 0.67 g desired catalyst along with 0.08 g Ru/Al 2 O 3 was prereduced in the reactor. 100 g of MDA/THF feed was then transferred to the reactor. The system was closed, leak checked and purged three times with nitrogen and then purged three time with hydrogen. The reactor was then pressurized with hydrogen to 850 psig and heated to 180° C. with agitation. (The volume and hydrogen pressure of the ballast were chosen to sufficiently provide all the hydrogen necessary for the reaction without dropping hydrogen pressure below 1000 psig.) When the rate of hydrogen consumption dropped to <2 psig/min, or the ballast pressure reached predetermined level, the reaction was terminated by turning off the heating and closing the hydrogen feed line. Once the reactor reached room temperature, the remaining hydrogen was vented and products were collected by filtration under 100 psig of nitrogen through a charge line containing a 2 μ filter. Table 1 shows the condition and results for a series of hydrogenation runs including a comparison with prior art catalysts. In some cases the catalysts were reused to determine catalyst life and, thus, these runs are numerically labeled. TABLE 1 Hydrogenation of 50% MDA/THF at 180° C., 850 psig pressure of hydrogen, Catalyst loading of 1.5 wt. % on the weight of MDA PACM- T95 b (or Half Deam Sec TEND) Conv. PACM t/t PAC Prods Amines Run Catalyst a use (min) (%) (%) (%) M (%) (%) (%) 1 4% Rh/Al 2 O 3 1 86 96 78.6 15.3 8.4 1.7 10.3 US 5,360,934 2 85 99 82.2 17.0 1.9 1.6 13.2 3 88 99 83.6 15.5 2.5 1.4 11.7 4 80 99 82.7 15.6 2.6 1.4 12.5 2 4% 1 100 99 71.4 13.3 1.7 1.6 25.3 Rh/TiAl 2 O 5 c 2 110 100 68.8 13.9 0.8 1.5 28.8 3 3% 1 180 98 76.7 13.8 4.7 1.7 16.9 Rh/TiAl 2 O 5 c 4 3% 1 155 99 94.6 18.0 2.5 0.6 1.5 Rh/LiAl 5 O 8 (from Ex. 6) 2 74 95 86.6 18.9 10.7 0.6 1.4 3 61 98 91.5 20.5 4.8 0.7 2.0 4 57 98 92.1 20.8 3.5 0.9 2.7 5 59 97 89.6 20.0 5.3 0.9 3.2 6 57 98 90.3 20.6 3.3 1.0 4.5 5 4% 1 123 97 90.4 17.9 6.2 0.6 1.9 Rh/LiAl 5 O 8 support from Ex 3 2 89 98 89.5 17.7 4.9 0.9 3.6 3 76 99 88.1 17.5 2.1 1.1 7.9 4 78 98 81.8 16.3 4.7 1.1 11.6 5 65 98 85.1 17.9 3.5 1.1 9.5 Conv. refers to conversion of methylenedianiline in weight percentage. Deam Products refer to deaminated methylenedianiline derivatives. PACM-Sec Amines refer to secondary amines of PACM. a 5% Ru/Al 2 O 3 was added such that the Rh:Ru ratio was 10:1 b Time for 95% conversion if the conversion is >95%. TEND is the estimated time for 95% conversion if a given conversion is <95%. c data from U.S. Pat. No. 5,545,756, Table 2, Runs 3, 3a & 4. From Table 1 it is shown that the Rh supported on LiAl 5 O 8 catalyst (Run 4) results in intrinsically higher selectivity to PACM than did the Rh on alumina catalyst (Run 1). While Rh/Al 2 O 3 resulted in 10-13% of PACM secondary amines as byproducts, the Rh/LiAl 5 O 8 catalysts from Examples 3 and 6 generated only 1-5% PACM secondary amines under the same reaction conditions. Such an increase in PACM selectivity was rather surprising since the Rh catalyst supported on mixed metal oxides, i.e., TiAl 2 O 5 generally always resulted in very high percentage of byproducts (such as PACM secondary amines) as shown by Runs 2 and 3. Rh/LiAl 5 O 8 is also more active than Rh/Al 2 O 3 . Even with only 3% rhodium, Rh/LiAl 5 O 8 was more active than Rh(4%)/Al 2 O 3 .(T95 ~ of 80 min vs. ~ 60 min). Runs 4 and 5 provide a comparison between supports calcined at 600 and 1000° C. Consistent secondary amine formation is achieved with the catalyst calcined at a temperature of 1000° C. Some secondary amine increases after the first use with the 600° C. calcined catalyst. This is most likely due to some support instability EXAMPLE 9 Water Sensitivity Testing A series of runs were conducted to determine the effect of water and LiOH in the hydrogenation reaction and the ability of the rhodium carried on a lithium aluminate support to accommodate water. Table 2 sets forth the results: TABLE 2 Influence of LiOH addition on hydrogenation of 50% MDA/THF at 180° C., 850 psig pressure of hydrogen, Catalyst loading of 1.5 wt. % on the weight of MDA T95 b PACM- (or Sec TEND) Conv. PACM t/t Amines Run catalyst a use (min) (%) (%) (%) External Additives c (%) 1 4% 1 138  99 86.8 18.7 2% LiOH/1 g H 2 O 6.1 Rh/Al 2 O 3 2 84 98 89.3 19.0 2% LiOH/1 g H 2 O 3.8 3 101  99 89.4 19.8 2% LiOH/1 g H 2 O 4.9 4 99 97 84.6 19.0 2% LiOH/1 g H 2 O 5.0 5 100  93 78.9 18.0 2% LiOH/1 g H 2 O 4.8 2 3% 1 79 98 91.0 21.3 0.5% LiOH/1 g H 2 O 1.8 Rh/LiAl 5 O 8 (from 2 97 97 91.7 23.0 0.5 g H 2 O 1.2 Ex. 6) 3 91 97 90.6 21.6 0.5 g H 2 O 1.8 4 94 98 92.2 21.7 0.5 g H 2 O 2.1 5 98 98 90.7 20.5 0.5 g H 2 O 2.6 6 103  97 90.6 22.4 0.5 g H 2 O 1.5 7 113  96 88.5 21.6 0.5 g H 2 O 1.8 Conv. refers to conversion of methylenedianiline in weight percentage. Deaminated products refer to deaminated methylenedianiline derivatives. PACM-Sec Amines refer to secondary amines of PACM. a 5% Ru/Al 2 O 3 was added such that the Rh:Ru ratio was 10:1 b Time for 95% conversion if the conversion is >95%. TEND is the estimated time for 95% conversion if a given conversion is <95%. c 2% LiOH/1 g H 2 O refers to 2 weight percent of Li as LiOH.H 2 O in 1 gram of water. The additive solution was added along with MDA feed. d 0.5 g H 2 O refers to the addition of 0.5 gram of water along with MDA feed. Commentary: In the hydrogenation process, water is always present and often its presence interferes with the effectiveness of LiOH in the PACM secondary amine control. This is particularly true when alumina is used as the catalyst support. The advantage of using lithium aluminate as the catalyst support is demonstrated by the enhanced effectiveness of LiOH as compared to Run 1 even when there is water in the MDA feed (Run 2 verses Run 1). Further control of the PACM secondary amine level was achieved by adding 0.5% LiOH to Rh(3%)/LiAl 5 O 8 catalyst. With merely one addition, the effect of LiOH carried over for the next 6 runs. The PACM secondary amine level was kept at a constant level of ~ 2%, (Run 2). By comparison, for the standard Rh(4%)/Al 2 O 3 catalyst, (Run 1) LiOH had to be added for each use and at a higher concentration (2%). The PACM secondary amines level was ~ 5%.

This invention relates to an improvement in a process for the catalytic hydrogenation of aromatic amines and to the resultant catalyst. The basic process for hydrogenating both mononuclear and polynuclear aromatic amines comprises contacting an aromatic amine with hydrogen in the presence of a rhodium catalyst under conditions for effecting ring hydrogenation. The improvement in the ring hydrogenation process resides in the use of a rhodium catalyst carried on a lithium aluminate support. Often ruthenium is included.

BACKGROUND OF THE INVENTION This invention relates to length measuring apparatus, and particularly but not exclusively concerns a length measuring apparatus for measuring accurately the length dimensions of labels which are for application to cans, bottles, and similar containers. As the description of the invention proceeds, it will be understood however, that the actual article which is having its length dimensions measured is immaterial as long as that article has the geometric characteristics to fit the apparatus. An article which has such characteristics can have its length dimensions accurately measured, and length dimensions can and do include height and width. As the apparatus was invented specifically to enable the accurate measurement of lables for cans, bottles or the like, reference will be made hereinafter only to the length dimensions of labels, but the views expressed above require the specification, unless the context specifically indicates or implies otherwise, to be construed accordingly. The application of labels to metal cans, such as beer cans, takes place at high speed, i.e. of the order of 600 to 900 labels per minute, and as labels are consumed at this speed from magazines, it is important that the labels be manufactured dimensionally to a high degree of accuracy. If they are not, then there can be problems with the extraction of the labels from the magazine. This is due to the fact that the labels are stacked so that the individual labels are in substantially vertical disposition, and if a batch of labels is taller than an adjacent batch, then they cause a distinct step in the top surface created by the stacked labels, and this step causes considerable difficulties in the high speed feeding of labels from the magazine. Customers therefore demand of label manufacturers that as regards labels for the above application, they must be manufactured to a high degree of accuracy. Label manufacturers must therefore quality control the manufacture of labels and continuously and conscientously check label length dimensions. SUMMARY OF THE INVENTION The present invention is an apparatus for providing such label length measurement, and seeks to provide an apparatus which will measure label length dimensions quickly and accurately. Label length measuring apparatus currently in use is a manually operated apparatus, involving the operator in manually viewing the label edges, and the positioning of a gauge to read label length dimensions. The present invention is an automatic label length measuring device, using currently available electronics, and the apparatus according to the invention comprises a datum mounting for the label and a light source and photoelectric means arranged to sense label edges, and means for displacing the datum support and light source and/or photoelectric means whereby respective label edges dictating a length dimension can be sensed as to position, and including means for providing a signal representative of the distance between the label edges so sensed. The means creating a signal may be connected to drive a display apparatus indicating the actual label length measurement. The said means operating the signal may comprise an encoder disc which is turned as the result of and in proportion to the amount of relative movement between the datum mounting and the light source and/or photoelectric means. Preferably, the datum mounting is a fixed surface, and there are two photoelectric means, at least one of which is position adjustable relative to the datum mounting, and the light source is movable in a predetermined linear path to provide a beam of light intersecting the datum mounting. Said light source may be provided by the end of an optical fibre cable, which is attached to a high precision lead screw, which is in turn coupled to an electric motor so as to be rotated when the apparatus is operative to drive a screw carrying the end of the optical cable. The datum support surface may be provided with a slot and a butting edge lying accurately at right angles to the slot and against which each label is butted, and the respective photocells may be positionable above the label edges where they intersect the said slot so that, as the light source travels along the line of the slot, the photocells will detect light up to the point where the light beam is intersected by the label edge, at which point the decoder disc will commence counting the shaft revolutions and parts thereof until the second photoelectric means senses the light beam as it emerges from under the opposite edge of the label. The signal generated by the encoder can readily be translated into length measurement. The method is very accurate, and the use of two photocells permits the approximate positioning of the label by the operator, because the photocell has a scan width, and as long as the label edge is positioned within that scan width, then accurate measurements can be obtained. The apparatus can readily be coupled to a microcomputer so that the results can be interpolated when the apparatus is used to test a large batch of sample labels. Typically, can labels are produced by large guillotines in ten or more reams simultaneously, and of each ten reams, the manufacturer may check the dimensions of six of these reams by taking a label from the top, a label from the middle and a label from the bottom of the ream. Experiments with the test apparatus show the method to be accurate and reliable, and more particularly quick. The apparatus also has the advantage that it can be coupled to computing equipment for averaging a large number of results automatically. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawing, of which FIG. 1 shows in perspective view a length measuring apparatus according to the invention, FIG. 2 shows how the photoelectric cells detect the label edges, and FIG. 3 shows a modification of the apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the apparatus shown in FIG. 1, there is a datum support surface 10 provided with a straight slot 12 and butting edge member 14 which lies accurately at right angles to the slot 12. The slot 12 traverses the abbuting edge member 14. The apparatus has two photocells 16 and 18, one of which is mounted on a pivot 19 lying at right angles to the slot 12, and is spring loaded so as to pivot away from the datum support surface to an extent permitting the insertion of a label under the photocell 16. When the label as indicated by numeral 20 is positioned in butting contact with the butting edge member 14, the photocell 16 is pressed downwards so as to lie over the label edge which butts against member 14, and the photocell can be held in the downwardly displaced position by means of a catch rod 22 which is pivotally mounted on a pivot rod 24 lying on one side of the datum support surface in a disposition parallel to the slot 12. When the rod 22 holds the photocell 16 in the downwardly depressed position, and end of the rod can be clipped into a retaining clip 26 at the opposite side of the datum surface. The second photocell 18 is mounted on pivot arm 28 also pivotally mounted on rod 24, and the length of the arm is such that when the photocell is pivoted downwards onto the datum surface, it lies in register with the slot 12. The photocell 18 and the arm 28 on which it is carried are slidable longitudinally of the rod so that the photocell may be accurately positioned in relation to the label edge. To this end, the top surface of the photocell may be provided with a datum line which is for aligning as accurately as possible with the edge of the label. It is not required that the edge of the label should be exactly aligned with the datum mark as will be explained in relation to FIG. 2. For the positioning of the label 20 whose length dimension is to be measured, it is simply a matter of positioning the label against the datum edge 14 whilst the photocell 16 is tilted to the up position, and the photocell 18 is moved clear of the datum surface. The photocell 16 is pivoted downwardly and then held captive by the captive rod 22. Next the photocell 18 is positioned as accurately as possible over the edge of the label 20 using the datum line thereon, and the label 20 is now positioned to have the length dimension which extends in the direction of the slot measured. To do this, it is simply a matter of depressing a button 30 of the apparatus which causes the rotation of a drive motor 32. The rotation of the drive motor 32 through a two to one transmission mechanism 34 causes rotation of a high precision lead screw 36 on which is mounted a drive nut 38. Attached to the drive nut 38 is the end 39 of an optical cable 40 providing an output light beam from the cable end. The light beam derives light from a light source 42. The end 39 of the cable 40 is aligned with the slot 12, and as the nut 38 moves, so the light beam from the end 39 of the cable initially passes through the slot 12 until it is interrupted at the label edge. This interruption is detected by the photocell 18 which electronically signals to counter 44 to count the coding marks on an encoder disc 46 driven by the lead screw 36, and the counter 44 counts these marks until the second photoelectric cell 16 detects the light beam emerging from under the other edge of the label. When the count stops, the total count is translated electronically onto a reading in a display area 48, giving an accurate measurement of the label length. FIG. 2 illustrates diagrammatically how the label length will be accurately detected provided that the label is positioned within reasonably wide limits. The photocell 18 detecting the arrival of the light beam prior to its being cut off by traversing the edge of the label 20 has a wide scanning area, and as long as the edge 20A of the label is in that scanning area, the presence of the label edge will be detected to establish a start count point, and similarly with the photoelectric cell 16 detecting the other edge 20B of the label there is a range of scanning for the photocell, and as long as the edge 20B is in that range, its position will be accurately detected by an abrupt change in the light sensed as the beam emerges from under the edge of the label, and a stop signal count will also be generated in order to terminate the counting means and initiate the conversion into a length measurement. Referring to the arrangement in FIG. 3, this is essentially similar to FIG. 2 in that indications of the length of the label are obtained, but only one photoelectric cell 18 is provided and it is adapted to move as indicated by the arrow so as to traverse the ends of the label 20 to sense ends 20A and 20B, there being two light beams 39 and 39A directed at the label ends 20A and 20B. This arrangement is basically the mechanical inversion of the arrangement shown in FIG. 2. In addition to displaying the length detected, the output may also be loaded into a computer 50 which can be programmed to store, sum, average and interpret the results. For example the computer may be programmed to give the extent of deviation from a motor of the lengths measured over a batch of readings. The invention provides a simple and effective means for determining label length dimensions, and as stated herein it can be used for other articles. The mechanical layout and components used can of course be varied within a wide range of designs without departing from the scope of the invention. The invention enables accurate measurement of labels because the device remains static during the measurement process. The accuracy of measurement from the device is to the second decimal place of millimetres. The nature of the device is such that it may be easily manufactured and is suitable for mass production.

This invention describes a length measuring device for measuring dimensions of (length and width) of labels which are for high speed application to bottles, cans and the like. A label to be checked is placed on a datum mounting plate, and a light source and photoelectric cell are arranged to sense the label edges as relative measurement in the direction of the label dimension to be measured and between the datum plate and light source takes place, thereby to obtain an indication of the label dimension.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims the priority of U.S. provisional patent application Ser. No. 61/353,301 filed on Jun. 10, 2010, which is incorporated herein be reference. FIELD OF THE INVENTION [0002] The invention relates generally to the fields of fluid handling and medicine. More particularly, the invention relates to methods and devices for dispensing lubricating gel in a clinical setting. BACKGROUND [0003] Lubricating jellies and other lubricants are used in a large variety of medical procedures such as ultrasound imaging and examination of orifices. In pelvic and rectal exams, lubricants increase patient comfort by reducing friction that can irritate delicate tissues. Lubricating jelly is typically supplied in large squeeze tubes or bottles, or in single-use packets. For the former, a health care provider will squeeze a suitable amount of the lubricant onto gloved fingers and then apply the lubricant to the patient. In cases where a health care provider performs multiple examinations in a day (e.g., an obstetrician/gynecologist), use of squeeze tubes or bottles can create a significant risk of cross-contamination—i.e., bodily fluids or tissues from one patient are inadvertently transferred to another patient. Although the health care provider will change gloves between each patient, if the provider handles the tube or bottle with gloves used to examine a patient, there is a good chance that the tube or bottle will become contaminated with that patient's bodily fluids or tissue. Because few health care providers clean the lubricant tube or bottle between patients, the next use of the tube or bottle can transfer a previous patient's bodily fluids or tissue first onto the gloves of the health care provider and then onto the next patient. [0004] Many practitioners are concerned about this issue and try to avoid contamination by using only one hand to contact the patient and the other hand to obtain lubricant from the squeeze tube or bottle. This of course can be quite awkward or even impossible to perform—especially in the case where two hands are required for the patient examination. As a result, lubricant containers are often contaminated—sometimes visibly so. [0005] To overcome this problem, medical lubricants are also sold in single-use foil packets that are torn open for each use. Unfortunately, opening an individual packet of gel can be a messy and cumbersome process. And occasionally, a packet will cut the health care provider's protective glove—a dangerous and unsanitary situation for both the practitioner and the patient. SUMMARY [0006] The invention is based on the development of a device for dispensing of lubricating jelly that is specifically designed to reduce the potential of patient to patient cross contamination and to be easy to use by a health care provider. The device dispenses a predetermined volume of lubricant automatically when a health care provider's hand is placed near a sensor on the device, and importantly is shaped and sized to prevent a user's hand or glove from accidentally touching any component of the dispensing device. The device can be coated with suitable anti-microbial agents—particularly at those areas likely to be accidently touched by a user. A removable and cleanable guard can also be used to prevent accidental touching of the dispensing valve. [0007] Accordingly, the invention features an automatic lubricant dispenser that includes a top component having at its front end a dispensing component, the dispensing component including a dispensing valve for dispensing the lubricant, a base for supporting the dispenser on a flat surface, and a middle component connecting the top component to the base, wherein the front portion the top component extends away from the middle of the front portion of the middle component at least 5 cm (e.g., at least 10 or 15 cm). The dispenser might also include a sensor for detecting the proximity of a user's hand to the dispensing valve and thereby activating a signal which causes the dispenser to deliver lubricant through the dispensing valve. The dispenser might also feature a contamination guard located in the front portion of the top component partially surrounding the dispensing valve. The contamination guard can be removable from the dispenser and/or be composed of (e.g., be made of, be coated with, or be impregnated with) an anti-microbial material. In one variation, the front portion of the middle component can include an anti-microbial material. [0008] Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications mentioned herein are incorporated by reference in their entirety. In the case of conflict, the present specification, including definitions will control. In addition, the particular embodiments discussed below are illustrative only and not intended to be limiting. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 is a schematic illustration of a lubricant dispensing device of the invention shown with a lubricating gel cartridge installed. [0010] FIG. 2 is a schematic illustration of the lubricating gel cartridge and the lubricant dispensing device of FIG. 1 shown with the lubricating gel cartridge removed. DETAILED DESCRIPTION [0011] The invention encompasses methods, devices, and kits for hygienically dispensing lubricants in a clinical setting. The below described preferred embodiments illustrate adaptation of these methods, devices, and kits. Nonetheless, from the description of these embodiments, other aspects of the invention can be made and/or practiced based on the description provided below. Dispensing Devices [0012] Referring now to FIG. 1 , in an exemplary embodiment of the invention, an automatic lubricating gel dispenser 5 includes a base 10 , a top component 20 , and a middle component 30 connecting the base 10 to the top component 20 . The front portion of the top component 20 (and optionally of the base 10 as shown in FIG. 1 ) extends away from the middle of the front portion 31 of the middle component 30 at least about 5 cm (e.g., at least 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 cm) to reduce the chance that a user's hand or glove will accidentally touch and possibly contaminate the middle component 30 . The front portion of the middle component 30 is shown in FIG. 1 as arcuate, although other arrangements are possible, e.g., straight. [0013] The height of the dispenser 5 should be sufficient so that a user can comfortably place his hand under the front portion 21 of the top component 20 , e.g., at least 10 cm, but preferably at least 15 or 20 cm. The height of the middle component 30 should also be sufficient for a user to comfortably place his hand under the front portion 21 of the top component 20 without contacting any part of the dispenser 5 , e.g., at least 8 cm, but preferably at least 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more cm. [0014] In the embodiment shown in FIG. 1 , although other configurations are possible, the base 10 is shaped and sized to securely sit on a flat surface such as a table top. For example, the bottom of base 10 can be substantially planar and made of a high friction material such as synthetic rubber. The base 10 is preferably sufficiently dimensioned to prevent tipping of the dispenser 5 , e.g., at least 8, 9, 10, 11, 12, 13, or 14 cm wide by at least 8, 9, 10, 11, 12, 13, or 14 cm long. Optionally, the base 10 can include a device for fastening the dispenser 5 to a flat surface, e.g., a suction cup 14 , an adhesive film, a magnet, or a hook and loop type fastener. A drip pan 12 can be included in the front portion of the base 10 to catch any excess lubricant that might drip after being dispensed. Preferably, the drip pan 12 is removable from the base 10 for easy cleaning. [0015] The dispenser 5 can be powered by any suitable means. Generally, the dispenser will be powered by electricity from batteries and/or an external current source. In the latter case, the dispenser 5 would include an electrical power cord 16 which could be located on the base 10 as shown in FIG. 1 , or less preferably on the top component 20 or the middle component 30 . [0016] The top component 20 can have a spout-like shape and a length of at least 10 cm, but preferably at least 15 or 20 cm so that a user can place his or her hand under the middle component 20 with little chance of accidently contacting the front portion of the middle component 20 . The top component 20 can include a dispensing component 22 on the bottom side of its front end as shown in FIG. 1 . The dispensing component 22 includes a dispensing valve 23 from which lubricant is dispensed, and optionally, a contamination guard 24 which partially surrounds the dispensing valve 23 (without blocking the delivery of lubricant) and protects it from being accidentally touched and contaminated by a user. The guard preferably extends downward farther (e.g., at least 0.3, 0.5, 0.75, 1, 1.5., or 2 cm) than the outlet on valve 23 to protect the outlet from accidentally being touched by a user. The contamination guard 24 is preferably removable from the dispenser 5 for easy cleaning. It can be made of any suitable material such as a plastic or metal, and can also be composed of an anti-microbial material (e.g., such as silver, an anti-microbial polymer, or an anti-microbial nanocomposite material). In an alternative configuration, rather than using a guard 24 to protect the valve 23 , the valve can be recessed (e.g., at least 0.3, 0.5, 0.75, 1, 1.5., or 2 cm) in an opening or bore on the underside of the front portion 21 of the top component 20 . In this arrangement, the portions of the top component 20 near the opening or bore could be composed of an anti-microbial material. [0017] To detect the hand of a user and thereby cause the dispenser 5 to dispense lubricant, the dispenser can include a sensor 25 such as an infrared sensor which detects the proximity of the users hand and responds by sending signals to other components (e.g., an electrical pump, conduits, and valves interposed between the lubricant storage component and the valve 23 ) of the dispenser 5 which cause the lubricant to be dispensed through the valve 23 . The sensor 25 can be located on the top component 20 as shown in FIG. 1 , but might also be located on the middle component 30 or the base 10 . A number of suitable sensors, pumps, and other components of this system are well known in the art. [0018] A refill warning device 26 such as a light or sound generator can also be included on the dispenser 5 to signal to a user that lubricant needs to be added. The dispenser 5 can also include a lubricant volume controller 28 which controls how much lubricant is dispensed per activation. This controller might be a rheostat or could be a switch with set volume levels (e.g., levels 1, 2, and 3). The amount of lubricant dispensed per activation could be between 2-10 ml (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10 ml +/−10%). [0019] The middle component 30 can include a reservoir into which lubricant is poured and stored, or preferably as shown in FIGS. 1 and 2 , an acceptor 32 for a pre-filled lubricant cartridge 34 . The acceptor 32 can be specifically designed to securely hold the cartridge 34 and align it with tubes that communicate with the valve 23 and other components such as a pump. The acceptor 32 might also be designed to puncture a sealing mechanism of the cartridge 34 so that lubricant would only be allowed to flow out of the cartridge 34 once the sealing mechanism was punctured. In the embodiment shown in FIG. 1 , a window 36 for showing the level of lubricant runs vertically through the outer wall of the cartridge 34 . The middle component 30 , and particularly the front portion of this component 30 , can include an anti-microbial material (see above) that could help kill any viruses and/or bacteria that might accidentally get on this component. [0020] For patient comfort, the dispenser 5 might also include a heating unit 38 (shown on the bottom portion of the middle component 30 in the embodiment shown in FIG. 1 ) for warming the lubricant. The heating unit 38 could be an electrical heating unit that can warm the lubricant to greater than 30° C. (e.g., 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 or more ° C.). [0021] As mentioned above, the outer surface of various parts of the dispenser 5 that are most likely to be accidentally contacted by a user's hand can include an anti-microbial material. In addition to this, the surface of the components making up the dispenser can be composed of materials that are resistant to being degraded by commonly used medical disinfectants such as alcohol. These materials might include metals (e.g., stainless steel, copper, and silver) or solvent-resistant plastics. [0022] In operation, a health care provider preparing to apply lubricant to a patient would place a gloved hand under the dispensing component 22 without touching any part of the dispenser. The sensor 25 would detect the gloved hand and send a signal to a pump or like device that would signal the dispenser 5 to move lubricant from the cartridge 34 out through the valve 23 . Because the dispenser 5 is never touched by the health care provider, he or she can obtain lubricant without contaminating the dispenser 5 even with a glove that might have a patient's bodily fluid or tissues on it. The elongation of top component 20 greatly reduces the chance that a health care provider will accidently touch the dispenser 5 , and the contamination guard 24 prevents a user from accidently touching the dispensing valve 23 . Other Embodiments [0023] It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. For example, the dispenser might be configured for wall mounting by having a means for securing the dispenser to a wall. Other aspects, advantages, and modifications are within the scope of the following claims.

A device for automatically dispensing lubricating gel for medical procedures that reduces the chance of cross-contamination between patients by use of a shape that prevent accidental contact with the dispenser, anti-microbial materials, and a dispensing valve protection device.

CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of U.S. patent application Ser. No. 59,888, filed by M. Rapoport and J. O. White on July 31, 1970 and now abandoned, disclosures of which are incorporated herein by reference. BACKGROUND OF THE INVENTION It is known in the art (British No. 777,087) that cyclohexyl hydroperoxide (CHHP) is formed in the air oxidation of cyclohexane (cyane) along with cyclohexanone and cyclohexanol. It is also well recognized that cyclohexanone and cyclohexanol can be converted by oxidation to adipic acid and that CHHP can be converted to cyclohexanone (K) or cyclohexanol (A) either in the course of the cyane oxidation or in a separate decomposition or conversion step. The development of processes for providing an optimum yield of adipic acid from these several intermediates has been the subject of extensive effort. Because CHHP may be used as an oxidizing agent for various purposes such as the oxidation of olefin materials, as well as an intermediate to the adipic acid precursors, K and A, cyane oxidation processes have been sought which would give a high proportion of CHHP in the reaction product. In U.S. Pat. No. 2,851,496 there is described a process for oxidizing cyane with or without a catalyst to give the corresponding hydroperoxide (CHHP) along with the adipic acid precursors K and A, and thereafter converting or decomposing the CHHP into K and A by heating in the presence of a decomposition catalyst. In U.S. Pat. No. 3,530,185 there is described a multistep process wherein cyane with or without catalyst is oxidized to give primarily K and A with lesser amounts of CHHP. In general, as stated in U.S. Pat. No. 3,530,185 and noted also in Japanese publication Oxidation, published by Kagaku Kogyo Sha, Aug. 10, 1963, pages 144-146, if catalyst is present the CHHP tends to be decomposed and the main products are K and A. It is further known that in the air oxidation of cyane in the absence of a catalyst a high proportion of the oxidized products is in the form of CHHP. In U.S. Pat. No. 3,510,526 a process is described which gives high yields of hydroperoxide by the air oxidation of a cycloalkyl compound such as cyane in the absence of a catalyst, in apparatus previously rendered passive by treatment with sodium pyrophosphate to minimize any catalytic effects of the equipment and with the added step on treating recycled cycloalkane with base to remove acidic by-products. Obtaining an increased yield of hydroperoxide by carrying out the oxidation in presence of an aqueous solution of an alkali metal or calcium pyrophosphate has also been described (U.S. Pat. No. 2,798,096). As noted above, air oxidation of cyane gives rise to the adipic acid precursors K and A as well as CHHP, which in turn can be converted to K and A. A complication attending the use of the various processes described is that appreciable amounts of peroxides other than CHHP may also be formed in the air oxidation of cyane and these also can undergo decomposition or conversion but to products other than K and A. This is indicated to be the case in U.S. Pat. No. 2,851,496, in U.S. Pat. No. 3,530,185 and in U.S. Pat. No. 3,719,706, the latter of which describes a process for isolating and utilizing a peroxide other than CHHP, namely 6-hydroperoxyhexanoic acid. Accordingly, a process has been sought for air oxidation of cyane which would provide a product stream containing a high proportion of CHHP along with K and A and which would be substantially free of peroxides other than CHHP. SUMMARY OF THE INVENTION A process has now been found for the oxidation of cyclohexane to a product fluid consisting essentially of unreacted cyclohexane, cyclohexanone, cyclohexanol and a high proportion of cyclohexyl hydroperoxide, the product fluid being substantially free of peroxides other than cyclohexyl hydroperoxide. The process is carried out by oxidizing cyclohexane (cyane) in a series of zones wherein cyane is fed downwardly through the zones and an oxidizing gas (gas containing molecular oxygen) is passed upwardly through the zones, the conditions being such that the amount of oxygen present in each reaction zone is in excess of that which will react under the particular conditions of that zone. The upward passing oxidizing gas after proceeding through the oxidizing zones is conducted through a series of oxygen cleanup zones wherein the oxygen content is reduced. On condensing the resulting off-gas from the reaction to reclaim unreacted cyclohexane the oxygen level is such that an explosive mixture is never formed. A suitable apparatus for carrying out the zoned oxidation is shown in the FIGURE, which is a sectional view of a tower oxidizer. To carry out the process of the present invention, the cyclohexane to be oxidized must contain a cobalt catalyst in the amount of about 0.1 to 5 parts per million parts of "product fluid". The term product fluid is defined as the fluid recovered exit the lowest oxidizing zone, the fluid containing cyclohexane, cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide and other oxidation products in minor amounts. More catalyst than the 5 parts per million results in significantly lower amounts of cyclohexyl hydroperoxide, because the peroxide at higher catalyst levels decomposes and reacts with the cyclohexane and thus cannot be recovered. At catalyst levels lower than 0.1 part per million the reaction becomes inefficient in that by-products including peroxides other than CHHP are produced and productivity as to desired products is lowered. Suitable cobalt catalysts include cobalt compounds, particularly cobalt salts of carboxylic acids, which are soluble in cyclohexane, such as cobalt naphthenate, cobalt octoate, cobalt laurate, cobalt palmitate, cobalt stearate, cobalt linoleate and cobalt acetylacetonate. The cobalt catalyst can be a cobalt salt as indicated above or as the reaction proceeds and product fluid as well as catalyst compounds are recycled to the process the catalyst may be in the form of cobalt salt of an organic acid produced in the course of the cyclohexane oxidation. An essential requirement is that the cobalt compound be soluble in cyclohexane so that it can be intimately associated with the cyclohexane in the course of its oxidation. Pyrophosphate salts may also be present along with the above-mentioned catalysts. As is illustrated in the accompanying FIGURE, details of which are discussed in the Description of Preferred Embodiments, cyclohexane containing the cobalt catalyst is first passed through a series of zones of oxygen cleanup where the cyclohexane is contacted and reacted with the gas that has been previously reacted with cyclohexane in the oxidation zone. The oxygen cleanup zone is operated at a temperature in the range of 130° to 180°C. and at a pressure of 60 to 350 psig. as measured at the top of the cleanup zone. In the oxygen cleanup zone most of the oxygen remaining in the gas that had previously contacted and reacted with cyclohexane in the oxidizing zones reacts further with cyclohexane so that the gas leaving the top of the reactor contains only a very low concentration of oxygen. The oxygen concentration in this off-gas measured after the cyclohexane condensation should be less than 4 mole % so that the gas will not form an explosive mixture. After passing through the oxygen cleanup zones, the cyclohexane passes into a series of oxidizing zones. These zones are maintained at a temperature in the range of 140° to 170°C., and since they are in the same reactor as the oxygen cleanup zones the pressure is in the same range as the oxygen cleanup zones: 60-350 psig as measured at the top of the cleanup zones. The temperature may vary from one oxidizing zone to another. In each oxidizing zone the concentration of the oxygen in the gas is kept at a level in excess of the amount of oxygen that will react with the cyclohexane feed in that zone; this is accomplished by adding the oxidation gas, usually air, at each zone. In addition, no more than 95% of the total oxygen fed to the oxidizing zones should be consumed in the oxidizing zones. After passing through the oxidizing zones, the product fluid is recovered. The product fluid will contain in addition to cyclohexane, cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide, other oxidation products in minor amounts, but substantially no peroxides other than cyclohexyl hydroperoxide. The percentage by weight of cyclohexyl hydroperoxide to the total of cyclohexanol, cycohexanone and cyclohexyl hydroperoxide as measured at the exit of the lowest oxidizing zone will be greater than 15%. Moreover, this process is useful where the extent of oxidation is such that the ratio, total air rate/product rate ##EQU1## is in the range of 0.1 to 0.7. Mscfh is defined as thousands standard cubic feet per hour, and gpm is defined as gallons per minute. The product fluid may then be employed as an oxidizing agent for olefins or it may be converted to K and A in a separate step as described in British Patent No. 777,087, or by carrying out the conversion in a lower part of the tower reactor. The advantages of the process of this invention over those of the prior art are that (1) the oxidized product contains a high proportion of cyclohexyl hydroperoxide (2) the oxidized product is substantially free of peroxide other than cyclohexyl hydroperoxide, (3) the process does not require passivation of the oxidation equipment and (4) process streams do not require treatment, for example, with alkaline solution before recycle to the process. Furthermore, even though the process is carried out with an excess of oxygen in the oxidizing zones, the incorporated oxygen cleanup feature provides for safe operation of this improved process. DESCRIPTION OF PREFERRED EMBODIMENTS The examples which follow are carried out in a reactor such as that illustrated in the FIGURE. The reactor 22, made of any suitable material such as 316 stainless steel, contains 21 equally spaced trays designated 1-21. The reactor height to diameter ratio is 8, and the downcomer opening 23 cross-sectional area for each tray to tower cross-sectional area is 0.12. The tower has inlet port 24 through which cyclohexane which contains a soluble salt of cobalt is introduced into the reactor, and off-gas port 25 through which the gaseous vapor containing relatively small amounts of oxygen is removed from the reactor. The catalyst may also be introduced at one or more other points in the oxygen cleanup zones. Each tray 1-21 contains a number of apertures (not shown) through which the oxidizing gas passes on way up the tower. Oxidizing gas may be fed to any or all of the first 18 trays. Since each tray must accommodate not only the gas fed to it alone but also gases from the trays below, the number and/or size of the apertures is progressively greater from the bottom to the top of the reactor. In examples where the lower 15 trays were used oxidizing gas was added at points designated 26-40, inclusive. The average free tray area (i.e., the area of the apertures in the trays) for all of the trays to tower cross-sectional area may vary widely but for the examples set forth below it is 1.2% calculated according to the following equation: ##EQU2## Recycled off-gas after removal of most of the contained cyane, K and A is introduced through inlet 42 through spargers 43. Outlet port 44 is used to remove the product continuously from the reactor. Sampling devices (not shown) to sample the gas or liquid may be inserted through reactor if desired, at selected locations. In operation the cyclohexane to be oxidized is introduced through inlet 24. It passes over tray 21 and the gas under tray 21 bubbles through the holes in tray 21 and through the cyclohexane. This flow across each tray while being subjected to the gas treatment is repeated as the cyclohexane moves down the tower. If desired, the oxidizing gas feed may be shut off at trays lower than tray 16, and thus increases the length of the oxygen cleanup zone (See Example 5). Recycled gas is introduced at 42 through sparger 43 to increase the volume of gas moving up the tower and thus providing mild oxidizing conditions throughout the tower, while at the same time stripping cyclohexane from the product fluid. The conditions used and results obtained in runs using cobalt naphthenate catalyst (Examples 1-5, 7, 8) and cobalt octoate (Example 6) are summarized in Table I. The peroxide composition of a typical run (Example 8) was determined as described below. It has been shown in the literature that the reaction of triphenylphosphine with hydroperoxides to form the corresponding alcohols is a general reaction as follows: R'OOH + R.sub.3 P → R'OH + R.sub.3 PO accordingly, 10 kilograms of the product fluid from Example 8 was reacted with triphenylphosphine (φ 3 P) according to the procedures described by L. Harner and W. Hurgeleit, Ann. 591, 138 (1955); L. Dulog and K. H. Burg, Z. Anal. Chem. 203, 184 (1964); D. B. Denny, W. F. Goodyear and B. Goldstein, JACS, 1393 (1960). Before and after treatment with triphenylphosphine the product fluid was analyzed for peroxides by a standard iodometric method (Mair, R. O and Graupner, A. J., Anal. Chem. 36, 194 (1964) and for cyclohexanol by a gas chromatographic method. The results, summarized below, show that the number of moles of cyclohexanol formed (0.7728) and the number of equivalents of peroxide (0.7774) consumed are essentially the same. Thus, the peroxides in the product fluid are essentially all cyclohexylhydroperoxide and do not contain significant quantities of other peroxides. ______________________________________ Analysis of Product Fluid Before After Reaction Reaction with φ.sub.3 P ofφ.sub.3 P Change______________________________________Equivalents ofPeroxide 0.7774 0 0.7774Moles of Cyclo-hexanol 0.6789 1.4517 0.7728______________________________________ TABLE I__________________________________________________________________________CYCLOHEXANE OXIDATION Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Ex.7 Ex.8__________________________________________________________________________No. of Oxygen Cleanup Trays 6 6 6 6 13 6 3 3No. of Air Feed Trays 15 10 15 15 8 5 18 18Actual Oxygen Cleanup Trays 16-21 16-21 16-21 16-21 9-21 16-21 19-21 19-21Actual Air Feed Trays 1-15 6-15 1-15 1-15 1-8 11-15 1-18 1-18Recycle Gas Rate scfhRatio of ,Product Rate lbs per hr 0.63 0.54.sup.(2) 0.66 0.39 0.67 0.31 0.31 0 1.08 1.11 1.34 0.85 0.87 0.60 0.79 0.44Total Air Rate scfh .sup.(1)Ratio of ,Product Rate lbs per hrProduct Rate, parts per hour.sup.(9) 440 440 432 380 429 350 1071 2029Feed Rate, parts per hour 530 520 500 405 540 412 1366 2263Cyclohexane recovered from 90 80 68 25 111 62 295 234off-gas, parts per hour Total Air Rate M scfh 0.36 0.37 0.45 0.28 0.29 0.20 0.26 0.14Ratio , , Product Rate gpmCatalyst Concentration, ppm Co 0.7 0.8 0.8 2.1 0.8 0.5.sup.(10) 0.5.sup.(12) 0.5.sup.(12)(introduced at Tray 19).sup.(3)Oxygen Conc. (mol % 0.sub.2, Dry Basis).sup.(8)Off-gas 1.0 0.9 1.02 0.8 1.4 0.35 3.78 2.32Tray 17 2.2 2.4 1.76 1.18 1.74 1.1.sup.(11) 5.1.sup.(11) 4.6.sup.(11)Tray 14 1.8 2.8 2.02 1.30 3.24 2.5.sup.11 5.2.sup.(11) 5.5.sup.(11)Tray 11 1.0 0.7 0.96 0.60 4.20 0.4.sup.(11) 5.2.sup.(11) 6.4.sup.(11)Tray 8 0.8 0.4 0.92 0.36 6.6.sup.(4) -- 5.5.sup.(11) 7.7.sup.(11)Tray 5 0.9 0.sup.(5) 0.86 0.58 -- -- 5.8.sup.(11) 10.3.sup.(11)Tray 2 0.5 0.sup.(5) 0.48 0.12 -- -- 5.4.sup.(11) 12.2.sup.(11)Mol % Oxygen Consumed in 86 85 88 93 54 74.sup.(11) 70.sup.(11) 83.sup.(11)Oxidation ZoneMol % Oxygen Consumed in 8 10 6 2 36 24 8 8Cleanup ZoneMol % Oxygen Unreacted 6 5 6 5 10 2 22 9Wt. % Total of cyclohexanone, cyclo- 4.91 4.59.sup.(6) 5.67 4.26 3.62 2.88 2.85.sup.(13) 1.91hexanol & cyclohexyl hydroperoxidein bottom oxidation trayWt. % cyclohexyl hydroperoxide in 1.37 0.93.sup.(6) 1.26 1.00 0.84 1.08 1.29.sup.(13) 0.90bottom oxidation traycyclohexyl hydroperoxide × 100 27.9 20.3.sup.(6) 22.2 23.5 23.5 37.5 45.1.sup.(13) 47.2Wt %cyclohexyl hydroperoxide +cyclohexanone + cyclohexanolin bottom oxidation trayWt % cyclohexanone + cyclohexanol + 5.22 4.85 6.19 4.46 3.92 3.11 3.06 1.91cyclohexyl hydroperoxide in productCyclohexyl hydroperoxide production 6.41 4.33.sup.(6) 5.94 3.98 3.90 4.08 14.78 18.32rate exit lowest oxidizing zone,parts per hr.sup.(7)Back Pressure, psig 120 125 130 112 115 135 154 152Tower Temp. Profile, °C. Tray 21 138 135 131 113 129 138 162 170 Tray 20 148 146 143 120 140 141 162.sup.(14) 169.sup.(14) Tray 15 154 157 159 146 154 155 160.sup.(14) 168.sup.(14) Tray 11 157 160 162 155 152 159 161.sup.(14) 168.sup.(14) Tray 10 156 160 162 154 151 -- 161 167 Tray 5 156 155 163 157 144 -- 160.sup.(14) 167.sup.(14) Tray 1 150 151 155 153 142 -- 155 166 Product 142 148 147 146 134 -- 153.sup.(14) 166.sup.(14).sup.(1) The total air used is distributed equally among all the air feedtrays..sup.(2) Recycle gas distributed 37% to base and 63% to Trays1-5.-.sup.(3) Calculated on product rate basis, cobalt naphthenate usedin Examples 1-5, 7, 8; cobalt octoate used in Example 6.sup.(4) Estimated exit Tray 8.sup.(5) Tray 6 is the bottom oxidation tray.sup.(6) Tray 5 compositions, one tray lower than the bottom oxidationtray Wt. % product cyclohexanone + cyclo- hexanol hydroperoxide .sup.(7) Cyclohexyl hydroperoxide flow rate = Product flow rate × 100 Wt. % cyclohexyl hydroperoxide/cyclohexanone + cyclohexanol + cyclohexyl hydroperoxide × 100The mass flow of cyclohexanone + cyclohexanol + cyclohexyl hydroperoxideexit the oxidationzone is essentially equal to the mass flow of cyclohexanone+ cyclohexanol + cyclohexylhydroperoxide in the product.Other salts of cobalt that are soluble in cyclohexane may be used as acatalyst for thereaction..sup.(8) Does not include the oxygen in the air feed to the designatedtray..sup.(9) Defined as the rate of product exit the reactor at outlet port44..sup.(10) Catalyst introduced at Tray 20..sup.(11) Calculated from cyclohexane oxidized..sup.(12) Catalyst concentration in feed..sup.(13) Calculated from tails concentration and cyclohexane vaporized..sup.(14) Interpolated from trays immediately above and__________________________________________________________________________below.

Preparation of cyclohexyl hydroperoxide substantially free of other peroxides by oxidation of cyclohexane containing a cyclohexane soluble cobalt salt in a zoned oxidation process in which an oxygen containing gas is fed to each zone in the oxidation section in an amount in excess of that which will react under the conditions of that zone.

This application claims the benefit of U.S. Provisional Application No. 60/045,231, filed Mar. 28, 1997, and U.S. Provisional Application No. 60/042,597, filed Apr. 1, 1997. FIELD OF THE INVENTION The present invention is related to low oxidation power, i.e. at low temperature and low oxygen concentration, thermal oxidation processes in the presence of a chlorine source. Said processes can be used during the manufacturing of semiconductor devices. Specific examples of use of such processes are the growth of ultra-thin oxide layers, the Cl-cleaning of a substrate and the temperature ramp-up cycles prior to the oxide growth. BACKGROUND OF THE INVENTION In thermal oxidation processes the aim is to grow SiO 2 films by exposing silicon to O 2 at elevated temperatures. Historically chlorine has been introduced in the oxidation ambient in order to improve the electronic quality of gate oxide layers. Studies have revealed that the improvements by introducing chlorine are in fact initiated by the presence of Cl 2 . Particularly the reduction of electronic instabilities, attributed to the presence of mobile ions mainly Na, has been emphasized. In addition, the use of Cl during gate oxidation was also found to result in a reduction of the density of dielectric breakdown defects and of stacking faults. It has been demonstrated that metal contamination on the wafer surface prior to gate oxidation has a distinct negative effect on the dielectric integrity of thin oxides. Particularly Ca has been identified as one of the most detrimental metals in that respect. The introduction of Cl in the oxidation ambient was found to be very efficient in removing metal contaminants, especially Ca, from the silicon wafer surface. In order to meet the stringent future gate-oxide defect density requirements, the residual concentration of metals and of Ca in particular has to be further reduced. Most oxidation tools are now equipped for the introduction of chlorine species during silicon wafer oxidation and/or in situ tube cleaning operations. Several sources have been used to introduce chlorine. In order to compare these different methods a common parameter describing the concentration of the total amount of Cl fed to the reactor chamber, irrespective of its chemical state, is introduced. Said parameter is the “chlorine-equivalent concentration of a given Cl-source” and is defined as the ratio between “the total flow of Cl atoms [number of Cl atoms per unit time ] to the process chamber” and “the total flow of all molecules [number of molecules per unit time] to the process chamber”. In the past it was common practice to feed HCl gas to the oxidation furnace. Although this gas was effective for this application, its use has several drawbacks. Because of its corrosive nature, this gas deteriorates the metal distribution lines as well as the metal components in the gas management system. Such corrosion phenomena result in highly undesirable metallic contamination of the gases. Moreover the handling of the pressurized gas cylinders requires special care. Because of these drawbacks the industry has used, 1,1,1-trichloroethane (TCA) as the source for Cl in the furnace. TCA is a volatile liquid and can be introduced into process tools via Teflon™ tubing thereby avoiding the corrosion phenomena faced with HCl. Since TCA has been identified as an ozone depleting substance, attacking the stratospheric ozone layer, its production, use and/or transportation has been restricted or even banned. In response the industry has come up with ozonelayer-friendly replacement substances for TCA such as trans-1,2-dichloroethylene (DCE) and oxalyl chloride (OC). The replacement with DCE is the subject of the United States patent U.S. Pat. No. 5,288,662. The replacement with OC is the subject of the European Patent EP 0 577262 B1. In virtually all industrial practice of Cl-oxidation, a Cl-equivalent concentration of the Cl-source of 1-3% is used as illustrated by the example1 and comparison2of the European Patent EP 0 577262 B1 and in the United States patent U.S. Pat. No. 5,288,662. In general, when Cl-carbon precursors are used, care has to be taken to get a complete enough combustion of the molecule. Regarding said combustion, the chemistry for OC is substantially different from that for either one of TCA or DCE. Because OC contains no hydrogen, all the Cl in the precursor is made available in the process tube as Cl 2 (equation 1), provided of course that water is not deliberately added. In contrast, as in HCl itself, in the TCA and DCE molecules the number of hydrogen atoms equals the number of chlorine atoms. Therefore, during combustion, TCA (equation 2) and DCE (equation 3) are sources for HCl. Only a fraction, typically about 10%, of the so formed hydrogen chloride is (further) oxidized to form Cl 2 and H 2 O, according to the equilibrium of the reaction (equation 4). It is obvious that said fraction depends on the parameters which affect the thermodynamical equilibrium like the percentage O 2 in the ambient. When this percentage is about 100%, said fraction is about 10%. C 2 Cl 2 O 2 +O 2 → Cl 2 +2 CO 2   (1) C 2 H 3 Cl 3 +2 O 2 → 3 HCl+2 CO 2   (2) C 2 H 2 Cl 2 +2 O 2 → 2 HCl+2 CO 2   (3) 4 HCl+O 2   2 Cl 2 +2 H 2 O   (4) Consequently to ensure a complete combustion of TCA and DCE, the O 2 concentration should be very high (a multiple e.g 10-fold of the stoichiometrical requirement) and the temperature should be sufficiently high. Therefore in the state of the art applications of Cl-carbon precursors, the Cl-source is only on when the larger fraction of the process chamber ambient consists of O 2 . Typically almost pure O 2 is used and only a smaller fraction of N 2 is added through the introduction of the Cl-carbon using a bubbler, as illustrated by the United States patent U.S. Pat. No. 5,288,662. The ongoing downscaling of CMOS device dimensions, in particular the gate length, demands for an ongoing reduction of the gate oxide thickness in order to meet the required device performance specifications. With this required shrinkage of the thickness of high quality gate oxides, the use of organic molecules to introduce Cl in the furnace has become more critical. In order to obtain a good thickness control the process for growing thin oxides requires a milder overall oxidation condition, especially a low temperature treatment and a reduced oxygen concentration. Consequently, the organic Cl containing molecules will undergo also a milder oxidation, yielding the risc of only partial combustion of said molecules and risc of formation of highly toxic compounds like e.g. phosgene. In recent years a new process was introduced referred to as the “pyro-clean”, see B.-Y. Nguyen et al, in Tech. Dig. 1993 Symp. on VLSI Technol., (JSAP, Tokyo, 1993) p. 109. In this process an in-situ low temperature Cl-treatment prior to the gate oxidation process is used. The motivation for this process is based on the fact that the diffusion constant and the solubility of a number of metals in silicon increases strongly with increasing temperature. The purpose of this process is to remove metallic contamination before the onset of diffusion of metal into bulk silicon. Typically a 30 minutes treatment at 650° C. is performed using an inert (e.g. N 2 ) ambient containing O 2 at a volume concentration of 2%. As a Cl source, HCl was chosen with a Cl-equivalent concentration of 3%. The addition of the small amount of oxygen is expected to be beneficial with regard to organic contamination, preventing destabilisation of the SiO 2 phase and limiting surface etching and roughening. At the same time the oxygen concentration should be kept low enough in order to limit the thickness of the oxide layer grown during this pre-oxidation step, particularly when the final oxide layers that are to be grown should be thin. The process conditions for the “pyro-clean” in B.-Y. Nguyen et al, in Tech. Dig. 1993 Symp. on VLSI Technol., (JSAP, Tokyo, 1993) p. 109 are a low temperature, a Cl-equivalent Cl-source concentration of 3% and a low oxygen concentration. In cited document HCl is used as a chlorine source. When using a chlorine-carbon source, it is obvious that this can result in a partial combustion, which is undesirable. Some early attempts in performing this process using TCA or DCE have even resulted in deposition of soot on the furnace wall and on the wafer surfaces, which is not possible when using OC. Moreover, even in an ambient with a high percentage of oxygen (even up to 100%) it is common knowledge that each of these substances have a minimum oxidation temperature below which a complete combustion is not possible. This minimum temperature is 800° C. for TCA, about 700° C. for DCE and as low as 400° C. for OC. As mentioned above, the use of the corrosive gas, HCl, in this process leads to potential danger of corrosion of the gas distribution system and is therefore undesirable. In an attempt to avoid the use of a corrosive gas and to overcome partial combustion of a Cl-carbon precursor, another approach, making use of a separate burn-box, has been proposed e.g. by Damon DeBusk et al, Miocro Sept. 1995, p.39. In this additional burn-box the organic precursor can be oxidized before being introduced into the process chamber holding the wafers to be oxidized. The relatively higher O 2 concentration, the potentially higher temperature and a long residence time of the gases in this burn box, contribute to obtain a better combustion. But this process has some drawbacks. The bum-box solution requires additional hardware and/or software (a torch-like device and modification in control hard and/or software). The use of a burn-box for the gases to be burned first and particularly the increased residence time in the burn-box may limit the control over the reactor ambient, particularly with respect to switching of the ambient. This in turn can result in a degradation of process control. And finally the burn-box approach may only be marginal in solving the problem. Particularly in case of processes with a low oxygen concentration. To illustrate this an example making use of DCE is taken where a Cl-equivalent concentration of 3% is aimed. To convert DCE to HCl and CO 2 stoichiometrically requires 2 oxygen atoms per Cl atom. To convert DCE to Cl 2 and CO 2 stoichiometrically requires 2.5 oxygen atoms per Cl atom. In case of full combustion of DCE, i.e. all C converted to CO 2 , typically a mixture of a larger fraction of HCl and a smaller fraction of Cl 2 is formed. Given said 3% Cl-equivalent concentration, an O 2 , volume concentration of 3 to 3.5% is required just to stoichiometrically match for the combustion of DCE. A large O 2 excess, in the order of 10 times is typically required to obtain the same amount of Cl 2 and to obtain full combustion during the finite residence time. Consequently the overall O 2 volume-concentration in the process chamber will be above 30%. This is clearly a much too high value to match the “pyro-clean” process. This severally limits the application of this technique to processes with relatively high oxygen concentration. The present invention provides a solution to overcome these drawbacks. AIM OF THE INVENTION It is the aim of the present invention to provide an efficient low oxidation power process that allows the growth of ultra-thin gate-oxides in a conventional furnace used in a standard CMOS IC-processing environment by using chlorine. Said process should avoid corrosion by using a Cl-carbon precursor and should at least maintain a performance equivalent to current HCl based processes. SUMMARY OF THE INVENTION In a first aspect of the invention a method is disclosed of in situ cleaning a silicon substrate by performing at least one heating step in a gas phase ambient comprising Cl 2 and preferably a very low concentration of oxygen, typically a volume concentration between 2% and 5% or below. This in situ Cl-clean can take place in a conventional oxidation furnace. Preferably said Cl-clean is performed in a gas phase ambient comprising the reaction products of oxygen (O 2 ) and an organic Cl-carbon based substance, preferably oxalyl chloride. Said reaction products can comprise oxygen, Cl-atoms and Cl 2 . The aim of this in situ Cl-clean is to remove the metal surface contaminants before they can diffuse into the substrate. In a second aspect of the invention a method is disclosed for growing a thin silicon oxide, preferably SiO 2 , on a silicon substrate using a gas phase ambient comprising Cl 2 . Said growth of silicon oxide can take place in a conventional oxidation furnace. More specifically a method is disclosed of growing said thin silicon oxide on said silicon substrate using a gas phase ambient comprising the reaction products of oxygen (O 2 ) and an organic Cl-carbon based substance, preferably oxalyl chloride. Said reaction products can comprise oxygen, Cl-atoms and Cl 2 . Using the method of the invention a controlled growth of thin silicon oxide layer on a silicon substrate can be achieved with the thickness of said silicon oxide layer in the range of 0.1 to 1 nm or 1 to 8 nm or above 8 nm. In a third aspect of the invention, a method is disclosed for growing a thin silicon oxide on a silicon substrate comprising at least two steps, in one step in an situ Cl-clean is performed and in another step a thin silicon oxide layer is grown on the silicon substrate using a gas phase ambient comprising the reaction products of oxygen and an organic Cl-carbon based substance, preferably oxalyl chloride. Using this method a controlled growth of a high quality thin silicon oxide layer on a silicon substrate can be achieved with the thickness of said silicon oxide layer in the range from 0.1 to 1 nm or 1 to 8 nm or above 8 nm. Said substrates of said first, second and third aspect of the invention are kept at a temperature of 900° C. or below. The present invention includes temperature ranges from 500° C. to 550° C., from 550° C. to below 700° C. and from 700° C. to 900° C. Preferably a temperature of 650° C. is used. Heating steps are typical in the range up to 30 minutes or 80 minutes or higher, but the invention is not limited thereto. In particular even oxidation or anneal times in the order of seconds may be used but such short anneal times usually require the use of pre-burning box. Furthermore a low Cl-equivalent concentration of oxalyl chloride in the gas phase ambient is used. Said Cl-equivalent concentration of oxalyl chloride can be in this range of about 0.001-0.3%. Said Cl-equivalent concentration of oxalyl chloride can also be in the range of 0.3-0.5% or in the range of about 0.5-1%. Higher concentrations can also be used. The gas phase ambient can also further comprise other gases or compounds that do not influence the efficiency of the method or that do not introduce contaminants in the grown silicone oxide. The gas phase ambient that is used can further comprise hydrogen or water steam but this reduces the efficiency. In a further aspect of the invention a method of growing a silicon oxide layer on a silicone substrate by means of a thermal oxidation in a furnace is disclosed, comprising the steps of: heating said substrate in said furnace, preferably said heating is executed in at least one step to at least one temperature typically in the range from 500° C. to 1000° C.; flowing a gaseous mixture into said furnace, said mixture comprising oxygen and Cl 2 , said Cl 2 being generated by an organic chlorine-carbon source, while keeping said furnace at a temperature below 700° C.; holding said silicon substrate in said furnace until said silicon oxide layer on said substrate is formed. In still a further aspect of the invention a method of growing a silicon oxide layer on a silicon substrate by means of a thermal oxidation in a furnace is disclosed, comprising the steps of: heating said substrate in said furnace; flowing a gaseous mixture into said furnace while keeping said furnace at a temperature below 900° C., said mixture comprising oxygen and Cl 2 , said oxygen having a volume concentration of 5% and below, said Cl 2 being generated by an organic chlorine-carbon source; holding said silicon substrate in said furnace until said silicon oxide layer on said substrate is formed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 presents the chemical structure of TCA, OC and DCE. FIG. 2 shows a scheme of the furnace temperature versus the time of a simplified exemplary oxidation process according to an embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION In relation to the appended drawings the present invention is described in detail in the sequel. Several embodiments are disclosed. It is apparent however that a person skilled in the art can imagine several other equivalent embodiments or other ways of practising the present invention e.g. by using equivalent chlorine sources, the spirit and scope of the present invention being limited only by the terms of the appended claims. In an embodiment of the invention a method is disclosed in situ cleaning a silicon substrate by performing at least one heating step in a gas phase ambient comprising Cl 2 . This in situ Cl-clean can take place in a conventional oxidation furnace. The Cl is generated from a Cl-source that works at a low oxygen concentration and at a low temperature. This is realised by using a well chosen concentration of an appropriate Cl-source that readily combusts even at temperatures of 700° C. or below. Additionally said Cl-source is chosen such that the same performance as with HCl as a source can be obtained at much lower Cl-equivalent concentrations and thus typically a low stoichiometric amount of oxygen is required for the combustion of the Cl-source. A Cl-source being efficient means that an equivalent performance is obtained at much lower Cl-equivalent concentrations than for conventional sources. An efficient source converts all of its Cl or at least a large fraction of its Cl into Cl 2 . Taking all thes aforementiond requirements into account, a good example of such a Cl-source is oxalyl chloride. Also other equivalent organic Cl-carbon sources e.g. having chemical formula C x Cl y O z H t , x, y and z being each one of 1, 2, 3 or 4 and t being one of 0, 1, 2, 3 or 4 which meet said requirements, and therefore readily combust even at temperatures of 700° C. or below, can be used. Preferably t is smaller than or equal to y. Therefore said Cl-clean uses a gas phase ambient comprising the reaction products of oxygen (O 2 ) and said organic Cl-carbon source (preferably OC). Said reaction products can comprise oxygen, Cl-atoms and Cl 2 . The aim of this in situ Cl-clean is to remove the metal surface contaminants before they can diffuse into the substrate. The substrates are kept at a temperature of 900° C. or below. The invention also includes temperatures in the range from about 500° C. to 550° C., from 550° C. to below 700° C. and from 700° C. to 900° C. Preferably a temperature of 650° C. is used. Heating steps are typical in the range up to 30 minutes or 80 minutes or higher, but the invention is not limited thereto. In particular even anneal times in the order of seconds may be used but such short anneal times usually require the use of a pre-burning box. Furthermore a low Cl-equivalent concentration of the Cl-source, preferably oxalyl chloride, in the gas phase ambient is used. Said concentration of oxalyl chloride can be in the range of about 0.001% to 0.3%. Said concentration of oxalyl chloride can also be in the range of 0.3% to 0.5% or in the range of about 0.5%-1%. Higher concentrations can also be used. The ratio between the total number of Cl atoms and the total number of O atoms should be kept below 0.1 or preferably even below 0.05. The lower the oxidation temperature and the lower the volume concentration of O 2 in the furnace the lower said ratio should be chosen. The gas phase ambient can also further comprise other gases or compounds that do not influence the efficiency of the method or that do not introduce contaminants in the grown silicon oxide. The gas phase ambient that is used can further comprise hydrogen or water stream but this reduces the efficiency. In a preferred embodiment of the invention a specific experiment of an in situ Cl-clean is disclosed. In the experiment oxalyl chloride (OC) was used as a chlorine source (Source in table 1). The heating step took place in an oxidation furnace, namely in an ASM A600, at a temperature of 650° C. during 30 minutes and with an O 2 volume concentration (O 2 in table 1) of 2%. The major component of the gas phase was nitrogen. Three different Cl-equivalent concentrations (Cl-eq. in table 1) of OC were tried out respectively 1, 0.3 and 0.05%. Also the ratio between the total number of Cl atoms and the total number of O atoms is given as an input parameter in table 1. This experiment was compared with two references. The first reference did use a conventional HCl-source as a Cl-source with a Cl-equivalent concentration of 3% (this is the conventional “pyro-clean”). Another reference was carried out without any Cl addition. As a specific example, the detailed description of the process conditions for one particular set of input parameters for the experiment is disclosed: detailed part of the experiment: OC: 0.05% Cl-eq.+2% O 2 , WAFERS: diameter: 150 mm orientation: <100> doping type: p-type oxidation furnace: ASM A600 load ambient: 25% O 2 in N 2 load temperature: 650° C. AMBIENT: total pressure: atmospheric clean ambient: 200 sccm O 2 , 9785 sccm N 2 clean temperature: 650° C. time: 30 min BUBBLER: ox.Cl: 2.5 sccm bubbler temp.: 12° C. Flow c /Flow s (at 12° C.): 4.961 carrier (N 2 ) flow setting: 12.4 sccm reading: 12-13 sccm source:Cl-eq setting: 0.05% reading: 0.05-0.06% (12-13 sccm N 2 carrier flow) The substrates were measured to control the thickness (tox in table 1) of the oxide layer grown. The thickness is determined with elliposmetry; the measurement tool used is: Plasmos, SD Version 6.28G, Ser. No.: 5062.03.93. Lightscattering haze measurements (haze in table 1), performed with the measurement tool Censor ANS100, provided a control for morphological integrity of the wafer surface. Also measured was the amount of Carbon incorporation (C incorp. in table 1), by means of polysilicon encapsulates SIMS, into the oxide films. Further measured was the removal efficiency of Ca (CA remov. in table 1) and Fe (Fe remov. in table 1) surface contamination which was intentionally put on dedicated substrates. The surface contamination level was measured with vapour phase decomposition-droplet surface etching-total reflectance X-ray fluorescence (VPD-DSE-TXRF). For the TXRF measurements an Atomika TXRF 8010 is used. The target value for the initial concentration of said contamination was 10 12 at. cm −2 . An overview of the input parameters and the results of the experiment is presented in Table 1. For the experiments without a chlorine source and with HCl as a chlorine source, the results of two runs, each having the same input parameters, are presented to demonstrate the repeatability. It can be seen in table 1 that for the conditions used the oxide thickness, haze, Fe-removal and particularly the carbon incorporation tend to correlate with the Cl/O ratio. The OC process with the highest Cl-equivalent concentration (1%) and a relatively high Cl/O ratio results in an anomalous fast oxide growth and a significant increase of the haze. TABLE 1 Overview of experimental conditions and major results for 650° C. 30 min treatments in an oxidation furnace. Ca Fe Cl-eq. tox haze C incorp. remov. remov. Source O 2 % % Cl/O nm ppm 10 13 cm −2 % % — 2 0 0 1.5 0.067 0.016 <14 <21 — 2 0 0 1.86 0.066 1.3 0 <23 HCl 2 3 0.75 1.7 0.067 0.075 85 49 HCl 2 3 0.75 2.1 0.066 0.24 >98 61 OC 2 1 0.25 11.5 0.87 20 >98 75 OC 2 0.3 0.075 3.6 0.080 2 >98 57 OC 2 0.05 0.013 2.3 0.067 0.2 >98 55 The carbon incorporation for the OC processes is clearly correlated with the Cl/O ratio. It is an indication of partially combusted OC in the oxidation ambient. In order to limit the carbon incorporation, one should avoid Cl/O ratios above 0.1. The Ca removal was found to be outstanding for all cases with Cl in the ambient, and for the conditions using OC in particular. Almost all OC processes have a Fe-removal efficiency which is comparable with the conventional pyro-clean using HCl. Except for the OC process with the highest Cl-equivalent concentration, where the Fe-removal efficiency is significantly higher, but on the other hand this process did result in a higher carbon incorporation. Oxalyl chloride (OC) with a Cl-equivalent concentration of 0.05% yields good results while OC with a Cl-equivalent concentration of 1.0% yields undesirable results. In summary it can be concluded that oxalyl chloride (OC), chemical formula C 2 Cl 2 O 2 , as Cl-source with a Cl-equivalent concentration of about 0.05% yields the same performance as HCl as a Cl-source with a Cl-equivalent concentration of about 3%. Consequently especially at low temperatures and low oxygen concentrations, OC is much more efficient (by a factor of approximately 60) than HCl. In another embodiment of the invention a method is disclosed of growing a thin silicon oxide, preferably SiO 2 , on a silicon substrate using a gas phase ambient comprising Cl 2 . Said growth of silicon oxide can take place in a conventional oxidation furnace. The Cl is generated from a Cl-carbon precursor that works with a low oxygen concentration and at a low temperature. These restrictions limit the choice of the Cl-source as already described above. Therefore the preferred Cl-source is oxalyl chloride. And thus in particular a method is disclosed of growing said thin silicon oxide on said silicon substrate using a gas phase ambient comprising the reaction products of oxygen (O 2 ) and oxalyl chloride. Said reaction products can comprise oxygen, Cl-atoms, Cl 2 . Using this method a controlled growth of a thin silicon oxide layer on a silicon substrate can be achieved with the thickness of the silicon oxide in the range of 1 nm to 8 nm or above. Also a thickness in the range from 0.1 nm to 1 nm is possible, such ultra-thin layers are e.g. grown to provide a well defined interfacelayer for poly-emitters in bipolar devices in order to guarantee a sharp transition between the polycrystalline emitter layer and the monocrystalline substrate. The heating step(s) for the growth of a thin silicon oxide layer are performed at a temperature of 900° C. or below. The present invention also includes temperatures in the range from about 500° C. to 550° C., to below 700° C. and from 700° C. to 900° C. Preferably a temperature of 650° C. is used. Heating steps are typical in the range up to 30 minutes or 80 minutes or higher, but the invention is not limited thereto. In particular even anneal times in the order of seconds may be used but such short anneal times usually require the use of pre-burning box. Furthermore a low Cl-equivalent concentration of oxalyl chloride in the gas phase ambient is used. Said concentration of oxalyl chloride can be in the range of about 0.001-0.3%. Said concentration of oxalyl chloride can also be in the range of 0.3-0.5% or in the range of about 0.5-1%. Higher concentrations can also be used. The O 2 volume concentration in the ambient can range from 0.1% to 5% or in the range from 5% to 100%. The gas phase ambient that is used can further comprise hydrogen or water steam. The gas phase ambient can also further comprise other gases or compounds that do not influence the efficiency of the method or that do not introduce contaminants in the grown silicon oxide. Characteristic about the Cl-clean and the growth of a thin silicon oxide described in the above embodiments is that there is O 2 and Cl 2 in the gas phase ambient, that a conventional oxidation furnace is used and that a silicon oxide is grown. As a consequence the method of the invention can be applied for each process which includes heat treatment steps and where at least traces of oxygen and chlorine are present in the ambient. In industrial processes this implies, growth of (ultra) thin oxides, pyro-clean processes, densification anneals but also more generally the use of Cl while the substrates are in the furnace, prior to the real oxidation step, this could be for e.g. a pryo-clean, a temperature ramp up and a temperature stabilisation prior to the oxidation step. These applications are characterised by a dilute O 2 ambient and/or low process temperature. To better explain this simple generic example of an oxidation process performed in a furnace is considered (see FIG. 2 ). Typically after bringing the substrates in the furnace ( 1 - 2 ), the furnace can be held at a constant temperature, the loading temperature, in order to allow the substrates to obtain the loading temperature ( 2 - 3 ). Then the temperature is increased to the nominal oxidation temperature ( 3 - 4 ). After a stabilisation step at the oxidation temperature ( 4 - 5 ) the real oxidation process starts ( 5 - 6 ). Finally the temperature is ramped down to the “unloading” temperature ( 6 - 7 ) and the substrates are unloaded ( 7 - 8 ). In general the oxide growth should be limited except during the actual oxidation step ( 5 - 6 ). Therefore from 1 to 5 the oxygen concentration in the furnace is chosen low. Also after the oxidation step (i.e. from 6 to 8) the oxidation is kept low by the freshly grown oxide that acts as a diffusion barrier for oxygen and by keeping the oxygen concentration in the furnace low. In practical oxidation processes the temperature evolution can be more complex, more “plateaus” can be built in the temperature-time evolution during which different steps can be performed. The oxidation steps can consist of several sub-steps (e.g. switching between wet and dry oxidation). The stabilisation time at the loading temperature can be taken essentially zero. However, the application of the method of the invention can be illustrated using the simplified generic description of an oxidation process. The Cl process that is the subject of this invention allows the use of Cl throughout almost the entire oxidation process (i.e. from 2 till 7): The use of the Cl process during 2 to 3 is then a Cl-clean. The use of the Cl process ramp up and stabilisation (3 to 5). The use of the Cl during oxidation (5 to 6) even if the oxidation ambient contains only a relatively small fraction of O 2 and eventually the use of Cl during ramp down (6 to 7). As an example of such a multi-step method, a method is disclosed comprising at least two steps, in one step an in situ Cl-clean is performed and in another step a thin silicon oxide layer is grown on the silicon substrate using a gas phase ambient comprising the reaction products of oxygen and an organic Cl-carbon based substance, preferably oxalyl chloride. Using this method a controlled growth of a high quality thin silicon oxide layer on a silicon substrate can be achieved with the thickness of said silicon oxide layer in the range of 1 nm to 8 nm above.

A method of growing a silicon oxide layer on a silicon substrate by means of a thermal oxidation in a furnace in the presence of a gaseous mixture, said mixture comprising oxygen and Cl 2 , said Cl 2 being generated by an organic chlorine-carbon source, particularly oxalyl chloride. This method is directed to the growth of (ultra) thin silicon oxides and/or the cleaning of a substrate using a low oxidation power. Consequently the method disclosed is especially suited for temperature below 700 ° C. and for oxidation ambients containing only small amounts of oxygen.

GOVERNMENTAL INTEREST The invention described herein may be manufactured, used, and licensed by or for the Government for Governmental purposes without payment to me of any royalties thereon. BACKGROUND OF THE INVENTION The present invention relates to projectiles for firing in a gun barrel, and in particular, to projectiles that have rotating parts to reduce projectile spin. For most small arms weapon systems, that is, weapon systems of caliber 40 mm or less, the gun barrels are rifled to induce a high angular spin to projectiles exiting the muzzle. Projectiles requiring spin for aerodynamic stability are called spin-stabilized projectiles. For other projectile types that do not require a high angular spin (or types that experience degraded performance when spun, e.g., fin stabilized projectiles) a "slip device" is normally mounted on the projectile body to reduce or eliminate spin induced by the rifling. This rotating device usually consists of a rotating band that is free to rotate or slip around the projectile body, thereby permitting only axial projectile motion and not rotational motion during firing. This technique has been used successfully with large caliber ammunition and in some instances with small caliber ammunition. A serious drawback with the foregoing technique is that the "slip device," which is usually composed of a polymeric type material, is exposed to the environment and is subject to possible damage. Rough handling by soldiers and exposure to machine oils are just a few possible situations that may damage the "slip device." This situation can lead to poor performance or failure of the ammunition if sufficient damage occur to the "slip device." Accordingly, there is a need for an arrangement to reduce the spinning of a projectile to avoid performance degradation in a way that is relatively immune to damage from handling. SUMMARY OF THE INVENTION In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a projectile for firing in a gun barrel. The projectile has a jacket and a bearing sleeve mounted in the jacket. This jacket is of different material than the bearing sleeve. A journal sleeve is mounted in the bearing sleeve to axially rotate therein. A load is mounted in the journal sleeve to rotate therewith. Thus the angular rotation of the load with respect to the gun barrel is reduced. In a related embodiment of the same invention, the projectile has a bearing sleeve, a journal sleeve and a load. The bearing sleeve has a predetermined axial length. The journal sleeve is of about the same predetermined axial length. Similarly, the load is about the same predetermined axial length. By employing apparatus of the forgoing type, an improved projectile is achieved. The preferred embodiment is able to reduce the angular rotation of the internal load of a projectile despite the rifling of the gun barrel. The preferred projectile may be of a small caliber although the technique may be applied to larger calibers. In a preferred embodiment, a projectile jacket uses a known structure that breaks apart on exiting the muzzle to permit release of an internal package. The preferred package includes a journal sleeve nested inside a bearing sleeve. Preferably both sleeves would be formed of a polymeric material having microencapsulated lubricants. In some embodiments, the bearing sleeve can be molded to the inside of the jacket. To lock the bearing sleeve in place, the bottom of the jacket can have one or more axially asymmetric concavities that prevent the bearing from slipping inside the jacket. In some preferred embodiments, either the bearing sleeve or the journal sleeve can have inter-sleeve projections that reduce the amount of surface contact between the sleeves. These projections reduce friction and allow the sleeves to rotate with respect to each other. Preferably, the two sleeves may be partially segmented to allow them to fold back petal-wise after firing. This arrangement can allow the load within the sleeves to be launched separately from the jacket. In some embodiments, the load may be a plurality of subloads such as flechettes, surrounded by buffering particles to keep the flechettes aligned during handling and firing. BRIEF DESCRIPTION OF THE DRAWINGS The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred, but nonetheless illustrative embodiments in accordance with the present invention, when taken in conjunction with the accompanying drawings wherein: FIG. 1 is an axial sectional view of the projectile according to the principles of the present invention; FIG. 2 is an axial sectional view of a journal sleeve in the projectile of FIG. 1. FIG. 3 is a back end view of the sleeve of FIG. 2; FIG. 4 is an axial sectional view of a journal sleeve that is an alternate to that of FIG. 2; FIG. 5 is a back end view of the sleeve of FIG. 4; FIG. 6 is an axial sectional view of a sleeve that is an alternate to that of FIG. 2; FIG. 7 is a back end view of the sleeve of FIG. 6. FIG. 8 is a back end view of the sleeve of FIG. 6, but modified to show a different projection pattern; FIG. 9 is a front end view of the sleeve of FIG. 2; FIG. 10 is a front end view of the sleeve of FIG. 2, but modified to have a different slit pattern; FIG. 11 is a front end view of the sleeves of FIGS. 4 and 6; FIG. 12 is a front end view of the sleeves of FIGS. 4 and 6, but modified to have a different slit pattern; FIG. 13 is an axial sectional view of a bearing sleeve in the projectile of FIG. 1; FIG. 14 is a back end view of the sleeve of FIG. 13; FIG. 15 is an axial sectional view of a sleeve that is an alternate to that of FIG. 13; FIG. 16 is a back end view of the sleeve of FIG. 15; FIG. 17 is a back end view of the sleeve of FIG. 15, but modified to show a different projection pattern; FIG. 18 is an axial sectional view of a sleeve that is an alternate to that of FIG. 13; FIG. 19 is a back end view of the sleeve of FIG. 18; FIG. 20 is a back end view of the sleeve of FIG. 18, but modified with a different projection pattern; FIG. 21 is an axial sectional view of a sleeve that is an alternate to that of FIG. 13; FIG. 22 is a back end view of the sleeve of FIG. 21; FIG. 23 is a front end view of the sleeves of FIGS. 13-22; FIG. 24 is a front end view of the sleeves of FIGS. 13-22, but modified to have a different slit pattern; FIG. 25 is a side view of the projectile of FIG. 1 mounted in a gun barrel shown partially and in section; and FIG. 26 is a view showing the projectile of FIG. 23 at the moment of launch and separation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a projectile 10 is shown with a jacket 12. The front of jacket 12 is designed to open or break apart to release its internal package upon existing the muzzle. This jacket is designed to handle the dynamic forces occurring during setback and firing and therefore can protect the internal package. In this embodiment, the internal package comprises a journal sleeve 18 nested within a bearing sleeve 34. Sleeve 34 has a pair of rear projections 38 that fit into corresponding concavities in the bottom of jacket 12. These projections 38 are not axisymmetric, but are a pair of diametric, hemispherical bosses. As such, projections 38 lock sleeve 34 in jacket 12 to prevent relative rotation between them. While the projections 38 tend to lock the bearing sleeve 34 in the jacket 12, in some designs a certain amount of slip between jacket 12 and sleeve 34 will be tolerated or desirable. Sleeves 18 and 34 are made of a polymeric material, preferably having a microencapsulated lubricant. Thus, sleeves 18 and 34 have the ability to relatively rotate. In the instance where projectile 10 is a caliber 0.50 mm projectile, the sidewalls of bearing sleeve 34 and journal sleeve 18 will be approximately 0.010 inch thick, while the base will be approximately 0.020 inch thick; although these dimensions may vary in other embodiments In this embodiment, the load 50 within sleeve 18 are anti-personnel/anti-material projectiles such as flechettes packed in buffering particles 52. The buffering particles may be material suitable for keeping the flechettes aligned as illustrated and acting as a shock absorber during handling and during firing. This design is more efficient since the package can be dispersed in the primary direction of a target; unlike an explosive munition in which the submunition are scattered and only a small percent are in a direct line with the target. While a plurality of flechettes are illustrated, the load could be instead a single projectile that does not require a high spin rate for aerodynamic stabilization. A mass stabilized projectile may be used. Referring to FIGS. 2 and 3, a generally, axially symmetric journal sleeve 18 is shown with a closed base and open front. The sleeve can be formed from a polymeric material and preferably include microencapsulated lubricant. Sleeve 18 is shown partially segmented by a plurality of slits 20 that may be 3 or 4 in number, although in alternate number of slits may be employed. In some embodiments, slits 20 need not go completely through the sleeve, but may be a narrowed rupture line that can tear apart after firing. The journal slits 20 allow the front of sleeve 18 to fold back into a plurality of petal segments. FIGS. 4 and 5 show a journal sleeve 21 similar to the foregoing sleeve, but modified to have eight journal bosses 22. The bosses are shown as external hemispherical projections, integrally molded with the material of sleeve 21. In this embodiment, the eight bosses are laid down in two circular patterns of four bosses each. Each circular pattern has bosses spaced equiangularly about the axis of the sleeve 21. Referring to FIGS. 6 and 7, the sleeve previously illustrated in FIG. 4 is modified and illustrated herein as sleeve 24 having additional pattern of four rear projections 26. In FIG. 8 an alternate pattern of 3 projections 28 are illustrated. Referring to FIGS. 9 and 10, a front view of the sleeve of FIG. 2 shows previously mentioned slits 20 arranged symmetrically at 90° intervals. In Figure 10, a front view of the sleeve of FIG. 2 is modified to show three slits 20A arranged symmetrically at 120° intervals. Referring to FIG. 11, the front view of the sleeves of FIGS. 4 and 6 is shown with a pattern of three slits 24c disposed symmetrically at 120° intervals. In FIG. 12, slits 24A are shown in a modified arrangement spaced symmetrically at 90° intervals. Referring to FIGS. 13 and 14, bearing sleeve 30 is shown as a generally axisymmetric sleeve with a closed base and an open front. Sleeve 30 is formed of a polymeric material with microencapsulated lubricants, similar to the previously described journal sleeve of FIG. 2. Also, sleeve 30 is shown with a plurality of bearing slits 32, which may pass through the entire thickness of sleeve 30 or in some embodiments be a narrowed rupture line designed to allow the front of sleeve 30 to fold backward into petal segments. Referring to FIGS. 15 and 16, the previously illustrated sleeve of FIG. 13 is shown modified as a sleeve 34 having a plurality of integrally molded, internal bearing bosses 36. In this embodiment four hemispherical bosses 36 are distributed equiangularly at 90° intervals. In some embodiments bosses 36 can be arranged as an annular internal ridge to provide support around a 360° locus. The rear of sleeve 34 is shown having a pair of hemispherical projections 38 for locking the position of sleeve 34. In FIG. 17, the projection pattern of FIG. 16 is modified to show three hemispherical projections 40. Referring to FIGS. 18 and 19, the sleeve previously illustrated in FIG. 13 is shown modified as a sleeve 41 having at its base an elongate projection 42, again for the purpose of locking the sleeve into position. In FIG. 20, the previously mentioned projection is modified into cruciform projection 44. Referring to FIGS. 21 and 22, the previously illustrated sleeve of FIG. 13 is shown modified to have a pair of rectangular projection 46. Also, internal bosses 48 are shown in a modified form. Referring to FIG. 25, projectile 10 is shown being fired through a gun barrel 16. Projectile 10 is shown having a jacket 12 that is designed to open or break apart along lines 14 to permit release of its contents upon exit from the muzzle. Jacket 10 is of a known design capable of withstanding the dynamic loads of setback and firing. Its structural rigidity is sufficient to keep its contents intact. As explained hereinafter, the slits 14 upon exiting the muzzle will allow the front segments of jacket 12 to fold back petal-wise to release its contents. To facilitate an understanding of the principles associated with the foregoing, the operation of the apparatus of FIG. 1 and 25 will be described in connection with FIG. 26. Projectile 10 is loaded into gun barrel 16 and fired in the usual fashion. Before firing the fit between the sleeves is snug but not tight. When fired through barrel 16, its rifling tends to spin jacket 12. Because projections 38 lock sleeve 34 to jacket 12, sleeve 34 spins as well. Advantageously, the spinning of sleeve 34 tends to drive its side walls outwardly to reduce the force between it and sleeve 18. Also, the centrifugal force tends to cause separation of the petal segments of sleeve 34 when leaving the muzzle. Since sleeve 18 and its load 50 have a certain amount of mass, load 50 does not tend to rotate with the sleeve 34. Instead, relative rotation occurs between sleeves 18 and 34. In instances where a bosses project between sleeves 18 and 34, the sleeves ride on the bosses and friction is correspondingly reduced. Upon leaving the muzzle, jacket 12 and bearing sleeve 34 will fold backwardly into the petal segment shown in FIG. 26. The journal sleeve 18 will fold in a similar fashion. At this time, load 50 is launched in the general direction of the target. Throughout the firing sequence, the buffering particles act as shock absorbers to maintain the relative position of the flechettes 50. After firing, the buffering particles are scattered and do not travel a significant distance. It is to be appreciated that various modifications may be implemented with respect to the above described preferred embodiment. For example, the caliber of the various components can be changed depending upon the load being fired. Furthermore, the load can be any type of load that may be fired by a gun. Furthermore, the materials of the sleeves can be other then polymeric and may be of any type of plastic, metal or other material suitable for firing. Also, the shape of the various projections can be altered depending upon the type of projectile, the expected forces etc. Obviously many 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 invention may be practiced otherwise than as specifically described.

A projecetile for firing in a gun barrel has a jacket and a load. A bearingleeve is mounted in the jacket and the jacket is of a different material than the bearing sleeve. A journal sleeve is mounted in the bearing sleeve to axially rotate therein. The load is mounted in the journal sleeve to rotate therewith. Thus angular rotation of the load with respect to the gun barrel is reduced.

BACKGROUND OF INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a leadframe for use in a semiconductor device with built-in heat sink, and to a resin-sealed semiconductor device that uses the leadframe. [0003] 2. Related Art [0004] In recent years, the miniaturization, high integration and high-density mounting of semiconductor components such as semiconductor devices has been sought in response to the miniaturization of electronic devices. This has resulted in the release of heat generated by semiconductor devices becoming a crucial issue. [0005] Semiconductor devices with built-in heat sinks or exposed die pads have been proposed as a countermeasure to the problem of heat release in semiconductor devices. For example, Japanese Patent Application Publication No. 2001-15669 discloses a semiconductor device with built-in heat sink. [0006] On the other hand, there is growing concern worldwide for the environment, which has lead to increasingly persistent calls for lead-free manufacturing also in relation to semiconductor devices. [0007] However, with a conventional semiconductor device having a built-in heat sink (i.e. two-tiered frame), it is necessary to limit the amount of adhesive used when adhering a semiconductor element to the heat sink, possibly creating a gap between the heat sink and the semiconductor element. Even in the case of the semiconductor device being sealed using sealing resin, the resin does not run into the gap, leaving space for absorbed moisture to gather. [0008] The mounting temperature when mounting a resin-sealed semiconductor device with built-in heat sink to a printed circuit board using lead-free solder is higher than for normal lead solder. This increases the temperature within the semiconductor device, which in turn raises the vapor pressure of absorbed moisture and promotes exfoliation of the semiconductor element from the heat sink, giving rise to the danger of internal bulging and cracking. SUMMARY OF INVENTION [0009] The present invention aims to provide a resin-sealed semiconductor device in which internal bulging and cracking is prevented even when mounted on a printed circuit board using lead-free solder, and a leadframe for use in the semiconductor device. [0010] To resolve the above problems, the present invention is a resin-sealed semiconductor device having a semiconductor element mounted on a heat sink. The semiconductor device includes: a plurality of outer leads for external electrical connection extending at right angles to sides of a rectangle; a plurality of inner leads in series at one end with the outer leads; the heat sink adhered to an underside of an opposite end of the inner leads; a plurality of substantially square openings provided in the heat sink so as to lie partially outside a mounting area for the semiconductor element and with sides thereof positioned at an angle to a direction in which the outer leads extend; the semiconductor element adhered by adhesive to an upper surface of the heat sink in an area sandwiched by the openings; a plurality of metallic wires electrically connecting the inner leads with corresponding electrode pads of the semiconductor element; and a sealing resin that seals the inner leads, the semiconductor element and the metallic wires, with the outer leads left exposed. [0011] According to the above structure, even if there is a gap between the semiconductor element and the heat sink, sealing resin runs into the gap via the openings. Exfoliation of the semiconductor element is thus prevented even in the case of lead-free solder being used to mount the semiconductor device to a printed circuit board, as is bulging or cracking of the sealing resin. [0012] Note that due to the improved leadframe, semiconductor manufacturing processes using conventional lead-solder may be directly applied as manufacturing processes using lead-free solder. [0013] Here, the sides of the openings may be positioned at an approximately 45° angle, and the semiconductor element may be adhered to the heat sink via a plurality of die pads. [0014] According to this structure, the formation of a gap is prevented because of the semiconductor element being securely adhered via a plurality of die pads. [0015] Here, the resin-sealed semiconductor device may further include a loop-shaped body encircled by the ends of the inner leads and surrounding the mounting area, the loop-shaped body being adhered to the upper surface of the heat sink via an underside thereof and having an inward protrusion positioned centrally on each side thereof. [0016] According to this structure, warping of the heat sink when adhering the heat sink to the underside of the ends of the inner leads during the manufacture of the leadframe is prevented, enabling the shape of the leadframe to be stabilized. [0017] The present invention is also a leadframe for use in a resin-sealed semiconductor device having a semiconductor element mounted on a heat sink. The leadframe includes: a plurality of outer leads for external electrical connection extending at right angles to sides of a rectangle; a plurality of inner leads in series at one end with the outer leads and electrically connected to electrode pads of the semiconductor element via connecting members; the heat sink adhered to an underside of an opposite end of the inner leads; a plurality of substantially square die pads adhered to the heat sink in a mounting area for the semiconductor element so that sides thereof are positioned at an angle to a direction in which the outer leads extend; and a plurality of openings provided in the heat sink so as to form a checkered pattern with the die pads. [0018] According to this structure, the semiconductor element can be securely adhered to the die pads of the leadframe with a small amount of adhesive. Moreover, the formation of a gap between the semiconductor element and the heat sink when manufacturing a resin-sealed semiconductor device that uses the leadframe is prevented because of sufficient sealing resin running between the semiconductor element and the heat sink via the openings. Thus, even in the case of lead-free solder (i.e. requires higher temperature than for normal lead solder) being used to mount the resin-sealed semiconductor device, bulging and cracking of the sealing resin due to the semiconductor element exfoliating can be prevented. [0019] Here, the sides of the die pads may be positioned at an approximately 45° angle, the openings may have rounded vertices, and each opening positioned circumferentially may lie partially outside the mounting area. [0020] According to this structure, sealing resin runs between the semiconductor element and the heat sink via openings positioned partially on the outside of the mounting area for the semiconductor element, enabling the formation of a gap to be securely prevented. Moreover, rounding the vertices of the openings allows the concentration of local stress to be alleviated. [0021] The present invention is also a method of manufacturing a leadframe for use in a resin-sealed semiconductor device having a semiconductor element mounted on a heat sink. The method includes the steps of: etching or stamping a piece of sheet metal to manufacture a metallic member that includes outer leads for external electrical connection extending at right angles to sides of a rectangle, inner leads in series at one end with the outer leads, substantially square die pads positioned with sides thereof at an angle to a direction in which the outer leads extend, a coupling ring coupling together the die pads, a dambar coupling the inner leads to the outer leads in side directions of the rectangle, and hanging leads holding the die pads from vertices of the dambar; adhering an upper surface of the heat sink to an underside of an opposite end of the inner leads and an underside of the die pads; and providing a plurality of openings in the heat sink to form a checkered pattern with the die pads and at the same time sectioning the coupling ring and the hanging leads. [0022] According to this structure, the die pads can be separated at the same time as the openings are formed, which avoids complicating the processes and allows for an improved leadframe. BRIEF DESCRIPTION OF DRAWINGS [0023] These and other objects, advantages, and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings, which illustrate specific embodiments of the present invention. [0000] In the drawings: [0024] FIG. 1 is a plan view of an embodiment 1 of a leadframe pertaining to the present invention; [0025] FIG. 2 is a bottom view of FIG. 1 ; [0026] FIG. 3 is a cross-sectional view cutting FIG. 1 at S-S′ of a resin-sealed semiconductor device that uses the leadframe of embodiment 1; [0027] FIGS. 4A-4F are cross-sectional views of processes for manufacturing the resin-sealed semiconductor device of embodiment 1; [0028] FIG. 5 is a plan view of an embodiment 2 of a leadframe with die pads pertaining to the present invention; [0029] FIG. 6 is a bottom view of FIG. 5 ; [0030] FIG. 7 is a plan view of the leadframe shown in FIG. 5 prior to openings being formed; [0031] FIG. 8 is a bottom view of FIG. 7 ; [0032] FIG. 9 is a cross-sectional view cutting FIG. 5 at S-S′ of a resin-sealed semiconductor device that uses the leadframe with die pads of embodiment 2; [0033] FIGS. 10A-10F are cross-sectional views of processes for manufacturing the resin-sealed semiconductor device of embodiment 2; [0034] FIG. 11 is a plan view of an embodiment 3 of a leadframe with loop-shaped body pertaining to the present invention; [0035] FIG. 12 is a bottom view of FIG. 11 ; [0036] FIG. 13 is a cross-sectional view cutting FIG. 11 at S-S′ of a resin-sealed semiconductor device that uses the leadframe with loop-shaped body of embodiment 3; [0037] FIGS. 14A-14F are cross-sectional views of processes for manufacturing the resin-sealed semiconductor device of embodiment 3; [0038] FIG. 15 is a cross-sectional view schematically showing the flow of sealing resin in embodiment 2; [0039] FIG. 16 is a cross-sectional view schematically showing the flow of sealing resin in embodiment 1; [0040] FIG. 17 is a plan view of a conventional leadframe used in a comparative example for verifying the occurrence of cracking etc. in the resin-sealed semiconductor device of embodiment 2; [0041] FIG. 18 is a bottom view of FIG. 17 ; and [0042] FIG. 19 is a cross-sectional view of a resin-sealed semiconductor device that uses the leadframe shown in FIG. 17 . DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0043] Embodiments of a leadframe and a resin-sealed semiconductor device that uses the leadframe pertaining to the present invention are described below with reference to the drawings. Embodiment 1 [0044] FIG. 1 is a plan view of an embodiment 1 of a leadframe pertaining to the present invention, while FIG. 2 shows a bottom view of the same. [0045] A leadframe 101 includes a rectangular frame 102 , a plurality of outer leads 103 extending at right angles to the four sides of frame 102 , a plurality of inner leads 104 that are in series at one end with the outer leads and extend toward the inside of frame 102 , and a heat sink 105 adhered to the underside of the opposite ends of inner leads 104 . A plurality of substantially square openings 106 with rounded vertices are formed at an approximately 45° angle to the direction in which the outer leads extend. The openings are positioned partially outside a mounting area 107 for the semiconductor element marked by the chain line. The border area between outer leads 103 and inner leads 104 is coupled in the four side directions of frame 102 by a dambar 108 . An area 109 marked by the chain line on the inside of dambar 108 indicates the area to be covered by sealing resin in a resin-sealed semiconductor device that uses leadframe 101 . [0046] The components of leadframe 101 apart from heat sink 105 are obtained by processing sheet metal made from copper alloy having a thickness of 0.15 mm and a hardness of 150 to 185 Hv, for example, using an etching or stamping technique. Heat sink 105 is a copper alloy sheet having a thickness of 0.13 mm, for example. Heat sink 105 is thermally adhered to the underside of the ends of inner leads 104 with adhesive. FIG. 3 is a cross-sectional view cutting FIG. 1 at S-S′ of a resin-sealed semiconductor device that uses leadframe 101 . [0047] A semiconductor element 301 is adhered to heat sink 105 in mounting area 107 thereof using a die bond 302 such as silver paste, for example. Electrode pads of semiconductor element 301 are connected to corresponding inner leads 104 by wires (e.g. metallic wires). The semiconductor device is resin sealed using a sealing resin 304 made from an epoxy resin, for example, with outer leads 103 left exposed. [0048] The processes for manufacturing a resin-sealed semiconductor device that uses leadframe 101 of the present embodiment are described next with reference to FIGS. 4A to 4F . FIGS. 4A to 4F are cross-sectional views cutting FIG. 1 at S-S′. [0049] FIGS. 4A and 4B show the manufacturing processes for leadframe 101 . [0050] FIG. 4A shows a process of using adhesive to adhere a metallic member (i.e. processed copper alloy sheet metal) that includes outer leads 103 and inner leads 104 etc. coupled together by frame 102 to the upper surface of heat sink 105 via the underside of the ends of inner leads 104 . Note that the cross-sectional views omit extraneous items to simplify the diagrams. The same approach is taken below. [0051] FIG. 4B shows a process of forming openings 106 by punch processing heat sink 105 adhered to the metallic member. This completes the manufacture of leadframe 101 . [0052] FIG. 4C shows a process of adhering semiconductor element 301 to leadframe 101 . Die bond 302 is applied at points 110 on heat sink 105 marked by the dotted lines in FIG. 1 , and semiconductor element 301 is placed over these points and adhered thereto. [0053] FIG. 4D shows a wire bonding process. The electrode pads of semiconductor element 301 are connected to the tip of corresponding inners lead 104 by wires 303 . [0054] FIG. 4E shows a resin sealing process. A mold is disposed so as to cover leadframe 101 and wires 303 while leaving outer leads 103 exposed, and a sealing resin made from epoxy resin is injected at a mold temperature of 180° C. The injection time is set to 8 seconds, for example. The mold is removed after cooling. [0055] FIG. 4F shows a process of bending outer leads 103 . Frame 102 of leadframe 101 is separated using a tie bar cut and outer leads 103 are bent to complete the manufacture of the resin-sealed semiconductor device. [0056] In the present embodiment, sealing resin injected via openings 106 which extend beyond mounting area 107 runs into the space between semiconductor element 301 and heat sink 105 , enhancing the adhesion of semiconductor element 301 with heat sink 105 . The formation of a gap between semiconductor element 301 and heat sink 105 can thus be prevented. Embodiment 2 [0057] An embodiment 2 of a leadframe with die pads and a resin-sealed semiconductor device that uses the leadframe pertaining to the present invention is described next. The following description relates only to the features of the present embodiment, with description of those parts similar to embodiment 1 having been omitted. [0058] FIG. 5 is a plan view of a leadframe with die pads, while FIG. 6 is a bottom view of the same. A plurality of die pads 502 is provided in mounting area 107 of a leadframe 501 so as to form an oblique checkered-pattern with openings 106 . Die pads 502 are substantially square in shape, and as with openings 106 the sides of the die pads are angled at approximately 45 degrees to the direction in which outer leads 103 extend. Those openings 106 positioned circumferentially lie partially outside mounting area 107 . [0059] Since openings 106 and die pads 502 surrounded by openings 106 form a checkered pattern and are angled at approximately 45 degrees to the direction in which outer leads 103 extend, the area of die pads 502 occupying mounting area 107 is ideal for applying the adhesive to adhere semiconductor element 301 . [0060] Hanging leads 503 protrude toward a central point from the vertices of dambar 108 of leadframe 501 . [0061] Heat sink 105 is adhered to the underside of both die pads 502 and the ends of inner leads 104 using adhesive. [0062] FIG. 7 is a plan view of the leadframe with die pads shown in FIGS. 5 and 6 prior to openings 106 being formed, while FIG. 8 is a bottom view of the same. [0063] Die pads 502 are coupled together by a coupling ring 701 , which is connected to dambar 108 via hanging leads 503 . The underside of die pads 502 , coupling ring 701 and hanging leads 503 are adhered to the upper surface of heat sink 105 using adhesive. [0064] Note that leadframe 501 excluding heat sink 105 is manufactured, similar to embodiment 1, by one-piece molding copper alloy sheet metal using a stamping technique, for example. [0065] FIG. 9 is a cross-sectional view cutting FIG. 5 at S-S′ of a resin-sealed semiconductor device that uses the leadframe with die pads. [0066] With this resin-sealed semiconductor device, die pads 502 are interposed between and adhered with adhesive to both semiconductor element 301 and the upper surface of heat sink 105 . The formation of a gap between semiconductor element 301 and heat sink 105 can thus be minimized since this expands the space between semiconductor element 301 and heat sink 105 and facilitates the flow of sealing resin 304 via openings 106 . [0067] The processes for manufacturing a resin-sealed semiconductor device that uses leadframe 501 of the present embodiment are described next with reference to FIGS. 10A to 10F . [0068] Note that FIGS. 10A to 10F are cross-sectional views cutting FIG. 5 at S-S′, and that extraneous items have been omitted to simplify the diagrams. Note also that description of the processes shown in FIGS. 10D and 10F have been omitted given the substantial similarities with processes shown in FIG. 4 of embodiment 1. [0069] FIG. 10A shows a process of using adhesive to adhere a metallic member (i.e. processed copper alloy sheet metal) consisting of outer leads 103 , inner leads 104 and die pads 502 etc. coupled together by frame 102 to the upper surface of heat sink 105 via the underside of both die pads 502 and the ends of inner leads 104 . [0070] FIG. 10B shows a process of forming openings 106 by punch processing heat sink 105 adhered to the metallic member and at the same time removing coupling ring 701 and part of hanging leads 503 to separate die pads 502 . Openings 106 , disposed so as to form a checkered pattern with die pads 502 , are substantially square in shape and positioned at an approximately 45° angle to the sides of the rectangular form of leadframe 501 . Also, those openings 106 positioned circumferentially lie partially outside mounting area 107 . [0071] FIG. 10C shows a process of adhering semiconductor element 301 to leadframe 501 . Die bond 302 is applied to the upper surface of die pads 502 , and semiconductor element 301 is placed over the die pads and adhered thereto. [0072] FIG. 10D to 10F are similar to embodiment 1. [0073] Note that the injection of sealing resin shown in FIG. 10E is made easier than in embodiment 1 as a result of the space between semiconductor element 301 and heat sink 105 . Embodiment 3 [0074] An embodiment 3 of a leadframe with loop-shaped body and a resin-sealed semiconductor device that uses the leadframe pertaining to the present invention is described next. The following description relates only to the features of the present embodiment, with description of those parts similar to embodiment 1 having been omitted. [0075] FIG. 11 is a plan view of a leadframe with loop-shaped body, while FIG. 12 is a bottom view of the same. Leadframe 1100 consists of the addition of a loop-shaped body 1101 that surrounds mounting area 107 for semiconductor element 301 to leadframe 101 of embodiment 1. Cap-shaped protrusions 1103 that protrude toward semiconductor element 301 are formed centrally on sides of loop-shaped body 1101 . Hanging leads 1102 that connect loop-shaped body 1101 to dambar 108 are formed at the corners of loop-shaped body 1101 . Note that apart from heat sink 105 , leadframe 1100 is integrally formed from sheet metal. [0076] FIG. 13 is a cross-sectional view of a resin-sealed semiconductor device that uses leadframe 1100 . This cross sectional view cuts FIG. 11 at S-S′. [0077] Loop-shaped body 1101 is disposed on the inside of inner leads 104 so as to surround semiconductor element 301 . A cross-section of protrusions 1103 is shown in FIG. 13 . [0078] FIGS. 14A to 14F are cross-sectional views illustrating processes for manufacturing leadframe 1100 and a resin-sealed semiconductor device that uses leadframe 1100 . Note that these cross-sectional views cut FIG. 11 at S-S′ with extraneous items having been omitted. [0079] FIG. 14A shows a process of adhering heat sink 105 to the metallic member. [0080] Adhesive is applied to the underside of both loop-shaped body 1101 and the ends of inner leads 104 , and the upper surface of heat sink 105 is adhered thereto by the adhesive. [0081] The provision of loop-shaped body 1101 connected to hanging leads 1102 on the inside of inner leads 104 in this process prevents the adhesion of heat sink 105 in a warped state, with any heat-related deformation being absorbed by protrusions 1103 provided centrally on the sides of loop-shaped body 1101 . [0082] Description of the processes in FIGS. 14B to 14D is omitted given the substantial similarities with processes in embodiment 1. [0083] The presence of loop-shaped body 1101 in the resin sealing process in FIG. 14E prevents sealing resin 304 from impacting on semiconductor element 301 when injected. [0084] The bending process in FIG. 14F is substantially similar to embodiment 1. [0085] Resin-sealed semiconductor devices that use the leadframes of the preferred embodiments have been described above, although the present invention can naturally be implemented through combining the features of these leadframes. [0086] An exemplary leadframe incorporates the die pads described in embodiment 2 with the loop-shaped body described in embodiment 3. [0087] The flow of the sealing resin in the resin sealing process of embodiments 1 and 2 is described next using FIGS. 15 and 16 . [0088] FIG. 15 shows semiconductor element 301 adhered to heat sink 105 via die pads 502 , while FIG. 16 shows semiconductor element 301 adhered directly to heat sink 105 . Semiconductor element 301 is adhered using die bond 302 in both cases, although when adhered to heat sink 105 via die pads 502 as in embodiment 2, a space equivalent to the thickness of die pads 502 is opened up between semiconductor element 301 and heat sink 105 . As shown by arrow A 501 , this enables the sealing resin to flow sufficiently into the space between semiconductor element 301 and heat sink 105 via openings 106 . Even with embodiment 1, the flow of sealing resin between semiconductor element 301 and heat sink 105 via openings 106 is as shown by arrow 1601 , preventing the formation of a gap. Comparative Example [0089] The following illustrates the results of comparative tests that assumed the use of lead-free solder in mounting a resin-sealed semiconductor device (“present device”) of the present invention manufactured according to embodiment 2 and a conventional resin-sealed semiconductor device (“conventional device”). [0090] A plan view of a conventional leadframe is shown in FIG. 17 , while a bottom view of the same is shown in FIG. 18 . With this leadframe, a single opening 1701 is provided in heat sink 105 below mounting area 107 . FIG. 19 is a cross-sectional view cutting FIG. 17 at S-S′ of a conventional resin-sealed semiconductor device that uses this leadframe. [0091] The present and conventional devices were firstly baked for 12 hours at 125° C. and dried, before being placed in an atmosphere having a temperature of 30° C. and a relative humidity of 70% for 72 hours to absorb moisture. Then, after having been subjected to a temperature of 265° C. for five minutes, the devices were again placed in an atmosphere having a temperature of 30° C. and a relative humidity of 70% for 96 hours. After again being subjected to a temperature of 265° C. for five minutes, the devices were cooled to room temperature and then supersonic waves were used to investigate for exfoliation and cracking. [0092] 15 samples of each device were used. [0093] The number of samples in which exfoliation or cracking occurred is shown in the following table. [0000] Comparative Results Exfoliation Cracking Present Device 0 0 Conventional Device 15 7 [0094] These results confirm that even when lead-free solder is used to mount the resin-sealed semiconductor device described in embodiment 2 on a substrate, exfoliation of the semiconductor element and cracking of the sealing resin is completely prevented. [0095] Note that while only a single leadframe is illustrated in the preferred embodiments, it is naturally possible to manufacture resin-sealed semiconductor devices by adhering and wire bonding semiconductor elements to a plurality of leadframes formed in series (above/below or to the left/right etc. of one another), and covering the leadframes with a mold and injecting sealing resin, before finally separating the individual semiconductor devices. [0096] Resin-sealed semiconductor devices using leadframes pertaining to the present invention are for use as environmentally friendly semiconductor devices in the field of semiconductor manufacturing. [0097] Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Therefore, unless such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.

A resin-sealed semiconductor device with built-in heat sink prevents internal bulging and cracking caused by exfoliation of a semiconductor element from the heat sink when the vapor pressure of moisture absorbed into a gap between the semiconductor element and the heat sink rises during mounting of the semiconductor device to a printed circuit board using lead-free solder. By providing a plurality of separated die pads ( 502 ) in a mounting area for a semiconductor element ( 301 ) and adhering the semiconductor element ( 301 ) to the heat sink ( 105 ) via the die pads ( 502 ), space is opened up between the semiconductor element ( 301 ) and the heat sink ( 105 ) for sealing resin ( 304 ) to run into.

CROSS-REFERENCE TO RELATED APPLICATION Applicant claims priority under 35 USC §371 of Korean Patent Application 2001-0020374, filed on Apr. 17, 2001, as a National Stage filing of PCT/KR01/00844, which was filed on May 22, 2001. FIELD OF THE INVENTION The present invention relates to a method for manufacturing plastic-substitute goods by using natural materials. Particularly, the invention relates to a method for manufacturing plastic-substitute goods by using natural materials, in which agricultural byproducts and wood byproducts such as rice husks, rice plant stems, corn plant stems, bean plant stems, wheat plant stems, saw dust and the like and the washed and dried sludge produced from the alcoholic factory are crushed into a particular size, then the crushed particles are mixed with natural adhesives (such as corn starch, potato starch and the like), and are coated with melamine resins or urea resins, and then a molding is carried out by applying a pressure in a molding machine, thereby manufacturing the natural plastic-substitute goods. BACKGROUND OF THE INVENTION There are various everyday goods which are made of plastic materials. Further, their shape and use are diversified, and have been continuously developed. However, the plastic materials are highly combustible, and therefore, in case of a fire accident, they are speedily burned off without allowing the fire fighting time. Further, when they are burned, toxic gases are generated to sacrifice human lives. When they are discarded, they are not decomposed, with the result that the natural environment is contaminated. SUMMARY OF THE INVENTION The present invention is intended to overcome the above described disadvantages of the conventional practice. Therefore it is an object of the present invention to provide a method for manufacturing plastic-substitute goods by using natural materials, in which one or more materials are selected from among agricultural byproducts and wood byproducts such as rice husks, rice plant stems, corn plant stems, bean plant stems, wheat plant stems, saw dust and the like and and the dried sludge produced from the alcoholic factory, then they are washed, sorted and dried, then they are mixed with natural adhesives such as corn starch, potato starch and the like, then they are dried and crushed, then they are mixed with a coating material such as melamine resins or urea resins, and then, they are press-molded in a molding machine. The agricultural byproducts and the wood byproducts can be selectively used, and the rice husks, rice plant stems and other plant byproducts can be mixedly used. As the natural adhesive, there can be used corn starch and potato starch, but other cereal powder may be used to reap the same effect. Corn starch and potato starch are preferred because they are cheap. The substitute materials are crude in their touching sense and in the color, and therefore, they can be dyed. Melamine resin or urea resin is a thermosetting resin which is formed by reaction of melamine or urea acting upon formaldehyde. A first mixture is produced by mixing formaldehyde solution 30 wt % and water 70 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degrees Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 w %. After drying and powdering this outcome, melamine resin or urea resin is obtained. The alkaline attribute of the formaldehyde liquid has a poisonous character, which is eliminated by heating at a high temperature after mixing in the melamine or urea. Said melamine resin and urea resin are generally called amino plastic because they have —NH2, the amino radical. These resins are colorless, transparent, easily colored, water-resisting and thermostable. Further, when molding the product of the present invention, the product can be easily separated from the molding die owing to the presence of melamine resin or urea resin, and therefore, the melamine or urea resin facilitating molding, separating and water-resisting of receptacle is an important element in the present invention. In the present invention, the molding is carried out at a temperature of 100-350 degrees C., the internal pressure is preferably 5 Kg/Cm 2 , and the molding speed is 30-80 seconds per product. The agricultural byproducts, the wood byproducts and other plant byproducts are mostly waste materials, and therefore, can be easily obtained. However, their availabilities are affected by seasons, and therefore, the most readily available materials in the season can be selectively used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The composition of the material of the present invention includes: one or more materials are selected from among agricultural byproducts such as rice husks, rice plant stems, corn plant stems, bean plant stems, wheat plant stems and the like, or wood byproducts such as saw dust and the like; the washed and dried sludge produced from the alcoholic factory; natural adhesives such as corn starch, potato starch and the like; and a coating material such as, melamine resin or urea resin and the like. The process for manufacturing the plastic-substitute goods by using natural materials according to the present invention includes: a material washing step; a washed material drying step; a step of dipping the dried materials into a glue; a step of drying the materials after the dipping into the glue; a step of crushing the dried materials; a step of mixing the crushed particles with a coating material; and a step of molding the mixed materials. The chemical compositions of the materials of the present invention will be analyzed in detail below. They were analyzed by the Korea Institute of Science and Technology as to its chemical composition. Therefore, the data which was prepared by the Korea Institute of Science and Technology will be referred to. Tables 1 and 2 analyze the ingredient materials which constitute the container made of rice husks and melamine resin or urea resin; and analyze the substances which are generated when burning the container. <Experiment 1> Table 1. Analysis of the materials constituting the container TABLE 1 Analysis of the materials constituting the container Analyzed items unit: Mass Test Decrease Piece SiO2 at heating Pb Cd As Hg Cu Material 10.8 88.3 0.0005 0.00005 0.0005 0.000005 0.0011 Test or less or less or less or less (*) (I) WET AAS AAS ICP AAS AAS Unit wt % wt % wt % wt % wt % wt % wt % Elution KmnO4 Phenols Formal- Diazinon Parathion Carbaryl Fenitro- Malathion consptn dehyde thion  1.5  0.047 0.7 0.001 0.001 0.005 0.001 0.001 or less or less or less or less or less (*) wet sp Sp Gc gc Gc gc gc Unit mg/l mg/l Mg/l mg/l mg/l mg/l mg/l mg/l In the above table, the heavy metals which are harmful to the human body are classified. Only silicon dioxide is 10.8 wt %, lead (Pb) is 0.0005 wt % or less, cadmium (Cd) is 0.00005 wt % or less, arsenic (As) is 0.0005 wt % or less, mercury (Hg) is 0.000005 wt % or less, copper (Cu) is 0.0011 or less. Thus the heavy metals are less than the standard values, and therefore, they cannot give toxicity to the human body. Silicon dioxide corresponds to the quartz sand, and therefore, it is not harmful to the human body at all probability. Therefore, the ingredient materials which constitute the material of the present invention are not harmful to the human body as can be seen in Table 1 above. Table 2 below shows the measurements of the environment polluting materials by Chungyong Environment Co., Ltd. so as to see the environment polluting degrees of the substances which are generated during the burning of the container which is made of the rice husks. <Experiment 2> Table 2. Measurement of environment pollution during the burning TABLE 2 Measurement of environment pollution during the burning Measured Measuring Items Standard result Method RMKS NH3 100 ppm ND Environment pollution test method CO 600(12) ppm 428.6 ″ HCL 50(12) ppm 9.76 ″ C12 60(12) ppm 11.5 ″ Sox 300(12) ppm ND ″ NOX 200 ppm 62.0 ″ CS2 30 ppm 0.75 ″ HCHO 20 ppm 3.3 ″ H2S 15 ppm ND ″ F 3 ppm ND ″ HCN 10 ppm 2.44 ″ Br 5 ppm ND ″ C6H6 50 ppm ND ″ C6H50H 10 ppm ND ″ Hg 5 mg/Sm 3 ND ″ As 3 ppm ND ″ DUST 100(12) mg/Sm 3 13.5 ″ Cd 1.0 mg/Sm 3 0.003 ″ Pb 5.0 mg/Sm 3 0.014 ″ Cr 1.0 mg/Sm 3 0.118 ″ Cu 10 mg/Sm 3 ND ″ Ni 20 mg/Sm 3 0.044 ″ Zn 30 mg/Sm 3 0.48 ″ O2 — 5.4% ″ *The combustion rate was 81.5%. As can be seen in Table 2 above, the density of the containers was high, and therefore, carbon monoxide (CO) was slightly generated during the burning. However, it was far short of the standard pollution value, and therefore, the container is a non-polluting material as can be seen in Tables 1 and 2 above. Therefore, as can be seen in the comparison of Tables 1 and 2, the materials of the present invention are also non-polluting materials. Now the method for manufacturing the plastic-substitute goods by using the natural materials according to the present invention will be described based on actual examples. EXAMPLE 1 Rice husks were washed to a clean state. The rice husks thus washed were dried to a drying degree of 98%. Meanwhile, 20 wt % of a starch was mixed with 80 wt % of water. This mixture was agitated, so that the starch and water could be uniformly mixed. After the confirmation of the agitation result, an aging was carried out while slowly heating the mixture up to 100 degrees C. in such a manner that the mixture would not be burned. When the mixture of the starch and water was heated, it became a glue. It was made sure that the glue would not be agglomerated, and thus, the required viscosity of the glue was maintained. The dried rice husks were mixed with the glue, and then, an agitation was carried out, so that the rice husks would be completely mixed with the glue. When it was confirmed that the rice husks and the glue were sufficiently mixed together, the mixture was dried to a drying degree of 98%. Here, the proportion of the starch glue was 20 wt %, while that of the rice husks was 80 wt %. After drying the mixture, it was crushed to a size range of 0.01 mm-0.1 mm. Then 70 wt % of the husk-starch mixture was mixed with 15 wt % of water and 15 wt % of melamine resin or urea resin to form the final mixture. The melamine resin or urea resin is made as follows. A first mixture is produced by mixing water 70 wt % and formaldehyde solution 30 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degree Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 wt %. After drying and powdering this outcome, melamine resin or urea resin is obtained. Then the final mixture was molded by a molding machine at a temperature of 100-350 degrees C. and at a pressure of 5 Kg/Cm 2 . The product was molded at a frequency of 30-80 seconds. EXAMPLE 2 Rice plant stems were cut to a certain length (3-5 cm). Then the cut stems were cleanly washed. The washed stems were dried to drying degree of 98%. Meanwhile, 20 wt % of a starch was mixed with 80 wt % of water. This mixture was agitated, so that the starch and water could be uniformly mixed. After the confirmation of the agitation result, an aging was carried out while slowly heating the mixture up to 100 degrees C. in such a manner that the mixture would not be burned. When the mixture of the starch and water was heated, it became a glue. It was made sure that the glue would not be agglomerated, and thus, the required viscosity of the glue was maintained. The dried rice plant stems were mixed with the glue, and then, an agitation was carried out, so that the rice plant would be completely mixed with the glue. When it was confirmed that the rice plant and the glue were sufficiently mixed together, the mixture was dried to a drying degree of 98%. Here, the proportion of the starch glue was 20 wt %, while that of the rice plant was 80 wt %. After drying the mixture, it was crushed to a size range of 0.01 mm-0.1 mm. Then 70 wt % of the rice plant-starch mixture was mixed with 15 wt % of water and 15 wt % of melamine resin or urea resin. The melamine resin or urea resin is made as follows. A first mixture is produced by mixing water 70 wt % and formaldehyde solution 30 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degrees Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 wt %. After drying and powdering this outcome, melamine resin or urea resin is obtained. Then the final mixture was molded by a molding machine at a temperature of 100-350 degrees C. and at a pressure of 5 Kg/Cm 2 . The product was molded at a frequency of 30-80 seconds. EXAMPLE 3 Saw dusts were cleanly washed. Then the washed saw dusts were dried to a drying degree of 98%. Meanwhile, 20 wt % of a starch was mixed with 80 wt % of water. This mixture was agitated, so that the starch and water could be uniformly mixed. After the confirmation of the agitation result, an aging was carried out while slowly heating the mixture up to 100 degrees C. in such a manner that the mixture would not be burned. When the mixture of the starch and water was heated, it became a glue. It was made sure that the glue would not be agglomerated, and thus, the required viscosity of the glue was maintained. The dried saw dusts were mixed with the glue, and then, an agitation was carried out, so that the saw dusts would be completely mixed with the glue. When it was confirmed that the saw dusts and the glue were sufficiently mixed together, the mixture was dried to a drying degree of 98%. Here, the proportion of the starch glue was 20 wt %, while that of the saw dusts was 80 wt %. After drying the mixture, it was crushed to a size range of 0.01 mm-0.1 mm. Then 70 wt % of the saw dust-starch mixture was mixed with 15 wt % of water and 15 wt % of melamine resin or urea resin. The melamine resin or urea resin is made as follows. A first mixture is produced by mixing water 70 wt % and formaldehyde solution 30 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degrees Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 wt %. After drying and powdering this outcome, melamine resin or urea resin is obtained. Then the final mixture was molded by a molding machine at a temperature of 100-350 degrees C. and at a pressure of 5 Kg/Cm 2 . The product was molded at a frequency of 30-80 seconds. EXAMPLE 4 Corn plant stems were cut into a length range of 3-5 cm. Then the cut corn plant stems were cleanly washed, and then, the washed corn plant stems were dried to a drying degree of 98%. Meanwhile, 20 wt % of a starch was mixed with 80 wt % of water. This mixture was agitated, so that the starch and water could be uniformly mixed. That is, the agitation was carried out while visually checking the mixing degree. After the confirmation of the agitation result, an aging was carried out while slowly heating the mixture up to 100 degrees C. in such a manner that the mixture would not be burned. When the mixture of the starch and water was heated, it became a glue. It was made sure that the glue would not be agglomerated, and thus, the required viscosity of the glue was maintained. The dried corn plant stems were mixed with the glue, and then, an agitation was carried out, so that the corn plant stems would be completely mixed with the glue. When it was confirmed that the corn plant stems and the glue were sufficiently mixed together, the mixture was dried to a drying degree of 98%. Here, the proportion of the starch glue was 20 wt %, while that of the corn plant stems was 80 wt %. After drying the mixture, it was crushed to a size range of 0.01 mm-0.1 mm. Then 70 wt % of the corn plant-starch mixture was mixed with 15 wt % of water and 15 wt % of melamine resin or urea resin. The melamine resin or urea resin is made as follows. A first mixture is produced by mixing water 70 wt % and formaldehyde solution 30 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degrees Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 wt %. After drying and powdering this outcome, melamine resin or urea resin is obtained. Then the final mixture was molded by a molding machine at a temperature of 100-350 degrees C. and at a pressure of 5 Kg/Cm 2 . The product was molded at a frequency of 30-80 seconds. EXAMPLE 5 Wheat plant stems were cut into a size range of 3-5 cm. Then the cut wheat plant stems were cleanly washed, and the washed wheat plant stems were dried to a drying degree of 98%. Meanwhile, 20 wt % of a starch was mixed with 80 wt % of water. This mixture was agitated, so that the starch and water could be uniformly mixed. That is, the agitation was carried out while visually checking the mixing degree. After the confirmation of the agitation result, an aging was carried out while slowly heating the mixture up to 100 degrees C. in such a manner that the mixture would not be burned. When the mixture of the starch and water was heated, it became a glue. It was made sure that the glue would not be agglomerated, and thus, the required viscosity of the glue was maintained. The dried wheat plant stems were mixed with the glue, and then, an agitation was carried out, so that the wheat plant stems would be completely mixed with the glue. When it was confirmed that the wheat plant stems and the glue were sufficiently mixed together, the mixture was dried to a drying degree of 98%. Here, the proportion of the starch glue was 20 wt %, while that of the wheat plant stems was 80 wt %. After drying the mixture, it was crushed to a size range of 0.01 mm-0.1 mm. Then 70 wt % of the wheat plant-starch mixture was mixed with 15 wt % of water and 15 wt % of melamine resin or urea resin. The melamine resin or urea resin is made as follows. A first mixture is produced by mixing water 70 wt % and formaldehyde solution 30 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degrees Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 wt %. After drying and powdering this outcome, melamine resin or urea resin is obtained. Then the final mixture was molded by a molding machine at a temperature of 100-350 degrees C. and at a pressure of 5 Kg/Cm 2 . The produce was molded at a frequency of 30-80 seconds. EXAMPLE 6 Bean plant stems were cut into a size range of 3-5 cm. Then the cut bean plant stems were cleanly washed, and the washed bean plant stems were dried to a drying degree of 98%. Meanwhile, 20 wt % of a starch was mixed with 80 wt % of water. This mixture was agitated, so that the starch and water could be uniformly mixed. That is, the agitation was carried out while visually checking the mixing degree. After the confirmation of the agitation result, an aging was carried out while slowly heating the mixture up to 100 degrees C. in such a manner that the mixture would not be burned. When the mixture of the starch and water was heated, it became a glue. It was made sure that the glue would not be agglomerated, and thus, the required viscosity of the glue was maintained. The dried bean plant stems were mixed with the glue, and then, an agitation was carried out, so that the bean plant stems would be completely mixed with the glue. When it was confirmed that the bean plant stems and the glue were sufficiently mixed together, the mixture was dried to a drying degree of 98%. Here, the proportion of the starch glue was 20 wt %, while that of the bean plant stems was 80 wt %. After drying the mixture, it was crushed to a size range of 0.01 mm-0.1 mm. Then 70 wt % of the bean plant-starch mixture was mixed with 15 wt % of water and 15 wt % of melamine resin or urea resin. The melamine resin or urea is made as follows. A first mixture is produced by mixing water 70 wt % and formaldehyde solution 30 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degrees Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 wt %. After drying and powdering this outcome, melamine resin or urea resin is obtained. Then the final mixture was molded by a molding machine at a temperature of 100-350 degrees C. and at a pressure of 5 Kg/Cm 2 . The product was molded at a frequency of 30-80 seconds. EXAMPLE 7 Sludge produced in alcoholic factory after extracting spirits consists of barley husks and alien substance. The sludge, when untreated, pollutes the environment. Therefore, after suitable treatment is made, the barley husks can be extracted in order to utilize in the present invention. The barley husks abstracted from the sludge were cleanly washed. The washed barley husks were dried to a drying degree of 98%. Meanwhile, 20 wt % of a starch was mixed with 80 wt % of water. This mixture was agitated, so that the starch and water could be uniformly mixed. That is, the agitation was carried out while visually checking the mixing degree. After the confirmation of the agitation result, an aging was carried out while slowly heating the mixture up to 100 degrees C. in such a manner that the mixture would not be burned. When the mixture of the starch and water was heated, it became a glue. It was made sure that the glue would not be agglomerated, and thus, the required viscosity of the glue was maintained The dried barley husks were mixed with the glue, and then, an agitation was carried out, so that the barley husks would be completely mixed with the glue. When it was confirmed that the barley husks and the glue were sufficiently mixed together, the mixture was dried to a drying degree of 98%. Here, the proportion of the starch glue was 20 wt %, while that of the barley husks was 80 wt %. After drying the mixture, it was crushed to a size range of 0.01 mm-0.1 mm. Then 70 wt % of the barley husks-starch mixture was mixed with 15 wt % of water and 15 wt % of melamine resin or urea resin. The melamine resin or urea resin is made as follows. A first mixture is produced by mixing water 70 wt % and formaldehyde solution 30 wt %. A second mixture is then achieved by mixing the first mixture at 70 wt % with melamine or urea 30 wt % and heating the result at a temperature of 350 degrees Centigrade. Then the resulting substance is mixed at 60 wt % with cellulose powder 40 wt %. After drying and powdering this outcome, melamine resin or urea resin is obtained. Then the final mixture was molded by a molding machine at a temperature of 100-350 degrees C. and at a pressure of 5 Kg/Cm 2 . The product was molded at a frequency of 30-80 seconds.

A method for manufacturing plastic-substitute goods by using natural materials is disclosed. Agricultural byproducts and wood byproducts such as rice husks, rice plant stems, corn plant stems, bean plant stems, wheat plant stems, saw dust and the like and the washed and dried sludge produced from the alcoholic factory are crushed into a particular size, then the crushed particles are mixed with natural adhesives (such as corn starch, potato starch and the like), and are coated with melamine resin or urea resins, and then a molding is carried out by applying a pressure in a molding machine, thereby manufacturing the plastic-substitute goods. The raw materials of the present invention are readily available from the rural areas, and the molding is carried out at a temperature of 100-300 degrees C.

[0001] This patent application is based on Provisional Patent Application No. 61/707,795, filed on Sep. 28, 2012. BACKGROUND OF THE INVENTION [0002] 1. Field of Invention [0003] This invention pertains generally to the field of lens fabrication and more particularly to inspecting and processing a lens during manufacture. [0004] 2. Description of Prior Art [0005] The fabrication of lenses includes processing steps to generate both lens surfaces in order to impart specific optical properties to the lens, and also to accomplish the peripheral alteration, or edging, of the lenses. The first step in altering a lens is typically the generation of a surface on a partially finished lens blank. The second step in processing the lens is normally the peripheral alteration of the shape of the surfaced lens. The lens blanks and surfaced lenses may be, for example, spherical, cylindrical, optical flats, aspherical, or of multiple focal lengths. Once the lenses have been finished they may be put to a variety of uses such as spectacle lenses, camera lenses, or lenses used in instrumentation. [0006] Edging the lens to obtain a desired shape involves a series of steps. Typically the optical center and the cylinder axis of the lens is located and marked on a surface. Next the lens is attached to a lens block by some type of holding mechanism, such as an adhesive, so that the optical center and the cylinder axis of the lens are aligned with the center point and cylinder axis of the block. The desired peripheral shape is then imparted to the lens via one or more drilling, cutting, milling, grinding or other machining tools. [0007] Typically the lens cutting and shaping tool is a computer controlled programmable device that may be frequently reprogrammed to manufacture a wide variety of lenses. In order to verify proper programming and operation of the lens forming tool, some means of calibration must be provided. [0008] For example, U.S. Pat. No. 7,191,030, entitled “METHOD FOR ESTIMATING THE ANGULAR OFFSET, METHOD FOR CALIBRATING A GRINDING MACHINE FOR OPTHALMIC GLASSES AND DEVICE FOR CARRYING OUT SAID CALIBRATING METHOD” utilizes a reference standard lens of a predetermined known shape. [0009] U.S. Pat. No. 7,668,617 entitled “METHOD OF CALIBRATING AN OPTHALMIC LENS PIERCING MACHINE, DEVICE USED TO IMPLEMENT ONE SUCH METHOD AND OPTHALMIC LENS MACHINING APPARATUS COMPRISING ONE SUCH DEVICE”, uses a template marked with an associated coordinate system. An additional drilling calibration device is used to calculate the difference between the apparent markings on the template and the actual drilling angles needed to create the desired lens. [0010] U.S. Pat. No. 7,970,847 entitled “METHOD OF CALIBRATING AN OPTHALMIC LENS PROCESSING DEVICE, MACHINE PROGRAMMED THEREFOR, AND COMPUTER PROGRAM”, presents a scheme for comparing the number of holes actually drilled in a lens with the number of holes predicted according to the programming of a drilling device. [0011] Further, some means must be provided to attach the lens blank to the edging block with a bond that will not fail during alteration but that will permit removal once alteration is complete. In practice, the lens may be removed from the edging block by a variety of methods. For example, the lens may be pried from the block. However, this method has the disadvantage that the lens is often chipped, scratched, or otherwise damaged by the act of prying. This method can be facilitated by immersing the lens and block in hot water for a short period of time. However, some plastic lens materials cannot withstand such temperatures. [0012] Another method of lens removal employs a tab that is pulled in the direction of the plane of the blocking pad so as to cause a reduction in the thickness of the pad and a progressive disengagement of the pad from the interface between lens and block. Removal may also be accomplished by placing the combination of lens, blocking pad and block into a cavity of the mounting block and then rotating the lens and the block in opposite directions with respect to each other, thereby causing them to separate. A specially designed hand tool may also be provided to accomplish this same result. The tool is not as wide as the mounting block and facilitates removal by making it easier to grasp the edge of the lens. [0013] The latter method of lens removal is disclosed in U.S. Pat. No. 3,962,833 entitled METHOD FOR THE ALTERATION OF A LENS AND AN ADHESIVE LENS BLOCKING PAD USED THEREIN, issued to Johnson on Jun. 15, 1976. The problem with the lens removal method disclosed by Johnson is that an operator must manually and repeatedly grasp pliers or a similar tool to remove the lens. Some level of skill is required to perform the lens removal operation rapidly while avoiding damage to the lens. After a period of time in such an occupation, the operator is likely to suffer various forms of fatigue and injury including, for example, carpal tunnel syndrome. [0014] Another method of lens removal utilizes a device that retains the blocked lens by means of a collet chuck or clamp. An example of such a device is disclosed in U.S. Pat. No. 8,182,314 entitled AUTOMATED EDGED LENS DEBLOCKING SYSTEM, issued to Goerges on May 22, 2012. The blocked lens resides on a pad which supports the lens on the edging block while protecting the lens from abrasion or damage from the block itself. A pair of opposed movable lens clamps or arms are pneumatically advanced to grip the blocked lens along portions of the lens edge. Once the lens is secured by the lens clamp, the collet chuck is rotated approximately forty five degrees, thereby breaking the bond between the lens and the edging block. The lens clamps may then be retracted away from the lens edges and the lens may be manually removed from the pad. [0015] A problem with the geometry of the '314 device is that repeated use causes wear on the collet chuck that leads to relatively premature failure, particularly when a hydrophobic adhesive pad is applied to an uncoated lens. Use of the hydrophobic pad requires a substantially greater force for lens removal than other pad/lens combinations, thereby accelerating the wear on both the collet and the edge block. [0016] What is needed is a visually verifiable lens template that permits a wide variety of lens parameters to be immediately inspected after a lens machining tool is programmed to create a specific lens. Any error or anomaly in the lens created, and the nature of the corrective action needed, should be apparent by viewing the lens template without further need of a machine based analysis. Further, the edged lens deblocking device must be capable of repeated industrial scale operation without failure. SUMMARY OF THE INVENTION [0017] The current invention is an improved apparatus and method for processing a lens that has undergone an edging procedure, including an improved apparatus for the removal of a lens from an edging block and a means for verifying the integrity and accuracy of the edging process performed on the lens. The edged lens is freed from an adhesive pad by the twisting motion of a collet. Periodically the edged lens is a calibration blank which may be inspected for compliance with the desired edging operations. [0018] In a preferred embodiment of the invention, a blocked lens is placed on each collet, the collet being formed to include an elongated cylindrical body that mates with an existing deblocking device such as the type described in the aforementioned U.S. Pat. No. 8,182,314. The collets are formed with a series of circumferential ribs surrounded by a larger circumferential wall that defines a bore. The edging blocks are formed to include a mating groove structure that accepts protrusions formed within the base of the bore. Some of the edging blocks are periodically affixed to a calibration blank having a series of parallel and intersecting lines, as well as circles or portions of circles, the lines and circles permitting rapid visual inspection of the edging or machining processes performed on the lens. These and other advantages of the present invention will become apparent by referring to the accompanying drawings and the detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0019] FIG. 1 is a perspective view of a prior art automated edged lens deblocking system; [0020] FIG. 2 is a perspective view of an automated edged deblocking system constructed according to the principles of the present invention; [0021] FIG. 3 is a perspective view of detail 24 of the automated edged deblocking system depicted in FIG. 2 ; [0022] FIG. 4 is a perspective view of the portion of the present invention indicated by rectangle 25 in FIG. 2 , with the chassis cover removed; [0023] FIG. 5 is a bottom plan view of the prior art edging block depicted in FIG. 4 ; [0024] FIG. 6 is a sectional view of the prior art edging block depicted in FIG. 1 taken along line 6 - 6 ; [0025] FIG. 7 is a perspective view of an edging block constructed according to the principles of the present invention; [0026] FIG. 8 is a bottom plan view of the edging block depicted in FIG. 7 ; [0027] FIG. 9 is a sectional view of the edging block illustrated in FIG. 8 , taken along line 9 - 9 ; [0028] FIG. 10 is a detail view of the edging block depicted in FIG. 9 , as indicated by the circle 10 ; [0029] FIG. 11 is a perspective view of a one piece collet constructed according to the principles of the present invention; [0030] FIG. 12 is a top plan view of the collet depicted in FIG. 11 ; [0031] FIG. 13 is a sectional view of the collet depicted in FIG. 12 , taken along line 13 - 13 ; [0032] FIG. 14 is a detail view of the collet depicted in FIG. 13 , illustrating the region within the circle 14 ; [0033] FIG. 15 is a detail view of the collet depicted in FIG. 14 , illustrating the region within the circle 15 ; [0034] FIG. 16 is a top plan view of a second embodiment of the collet of the present invention; [0035] FIG. 17 is a top plan view of the collet of FIG. 11 and an alternate embodiment of an edging block combined to create a lens blank manipulation assembly; [0036] FIG. 18 is a sectional view taken along line 18 - 18 as shown in FIG. 17 . [0037] FIG. 19 is a side elevation of the second embodiment of the collet depicted in FIG. 16 shown and the edging block depicted in FIG. 7 combined to create a lens blank manipulation assembly; [0038] FIG. 20 is a sectional view taken along line 20 - 20 as shown in FIG. 19 ; [0039] FIG. 21 is a side elevation of a collet closer as used in conjunction with the present invention; [0040] FIG. 22 is a sectional view taken along line 22 - 22 as seen in FIG. 21 ; [0041] FIG. 23 is a front elevation view of a first embodiment of a calibration lens constructed according to the principles of the present invention; [0042] FIG. 24 is a front elevation view of a second embodiment of a calibration lens constructed according to the principles of the present invention, including dimensional information; [0043] FIG. 25 is a sectional view of the calibration lens illustrated in FIG. 24 taken along the line 25 - 25 ; [0044] FIG. 26 is a detail view of the calibration lens as illustrated in FIG. 24 within the region 26 ; [0045] FIG. 27 is a front elevation view illustrating a calibration standard used in conjunction with the present invention; [0046] FIG. 28 is a front elevation view illustrating the utilization of a first calibration lens constructed according to the present invention, showing the portion of the calibration lens that remains after the calibration lens has undergone machining operations; and [0047] FIG. 29 is a front elevation view illustrating the utilization of a second calibration lens constructed according to the principles of the present invention, showing only the portion of the calibration lens that remains after the lens has undergone desired machining operations; and DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0048] Referring to FIG. 1 , a prior art automated edged lens deblocking device is shown generally at 1 . The deblocking device 1 includes a protective cabinet 2 typically composed of a durable metal or plastic material. The top surface 9 of the cabinet 2 is formed to include a generally rectangular aperture or slot 3 above which a pair of opposed arms 4 and 5 are slidably mounted by means of supports 6 and 7 . The supports 6 and 7 permit movement of the arms 4 and 5 in the directions generally indicated by arrow 8 . The top surface 9 also includes an opening or first circular aperture 10 which permits access to a first collet or edging block clamp 11 . A second circular aperture 12 is located in a symmetrical position opposite the rectangular aperture 3 . The circular aperture 12 permits access to a second collet or edging block clamp 13 . [0049] The edging block clamp 13 is intended to mate with an edging block. As seen in FIGS. 5 and 6 , a prior art edging block 28 includes a series of inclined surfaces, such as surfaces 29 , 30 , 31 and 32 , for example. Additionally the block 28 includes a diametric groove 33 which broadens to a keyway 34 at one end. The block 28 also contains a pair of substantially circular indentations 35 and 36 . At least some of the features such as the surfaces 29 - 32 , the groove 33 , the keyway 34 , the indentation 35 and indentation 36 are adapted to mate with and be gripped either by or within an edging block clamp, such as clamp 11 , when the block 28 is placed on the clamp 11 and toggle switch 19 is activated. The greatest diameter 37 is typically 0.707 inch with a thickness 38 of 0.110 inch. The depth 39 of the groove 33 is 0.085 inch. [0050] FIGS. 2, 3 and 4 illustrate the present invention, which includes a first elongated collet 22 and a second elongated collet 23 . The first elongated collet 22 extends through the first circular aperture 10 , while the second elongated collet 23 extends through the second aperture 23 . With the top surface 9 of the cabinet 2 removed, the first elongated collet 22 is seen to be mounted on first collet closer 26 . The second elongated collet 23 is mounted on a second collet closer 27 . [0051] FIGS. 7, 8, 9 and 10 depict a novel edging block 40 that is intended for use with the elongated collets 22 and 23 . The edging block 40 includes a series of inclined surfaces such as surfaces 43 and 44 , for example, that are shaped and dimensioned to engage the collet 22 . The circumferential space occupied by each surface 43 or 44 , for example, is approximately 7.5 degrees, creating an angle 47 of approximately 15 degrees between two adjacent surfaces or an angle 48 of approximately 22.5 degrees between three successive surfaces. The present invention also includes a plurality of circular bores 45 and 46 for engagement with suitable fixtures that may be used to secure the edging block during lens machining operations. The edging block 40 includes a centrally located groove 41 terminating at keyway 42 . As best seen in FIG. 9 , the groove 41 includes a blade or protrusion 49 extending from the bottom surface 50 of the groove for a distance 51 of approximately 0.080 inch. The angle 53 between the sidewall 52 of blade 49 and the bottom surface 50 is approximately 91 degrees. The length 54 of the blade 49 is approximately 0.145 inch. The outer lip 55 of the edging block 40 has a thickness 56 of approximately 0.110 inch, while the diameter 57 between the opposed inclined surfaces 58 and 59 is approximately 0.707 inch. The overall height 60 of the edging block 40 is approximately 0.316 inch, while the depth 61 of groove 41 is approximately 0.205 inch. [0052] The elongated collet 22 that receives the edging block 40 is depicted in greater detail in FIG. 11 . The elongated collet 22 is formed to include a generally cylindrical sidewall 62 that is partially separated by three longitudinal slots 63 , 64 and 74 . Each slot, such as slot 63 , extends through a frustoconical transition 69 that terminates at lip 70 . Integrally formed with and adjoining the transition 69 is a turret 76 that surrounds a base 75 . Also integrally formed with the sidewall 62 is a base 72 which includes at least one keyway 73 that is adapted to mate with a motor, gear, piston or other fixture that can rotate the elongated collet about the longitudinal axis 235 . Typically, the base 72 includes threads that are compatible with a receptacle such as a collet closer. [0053] Referring also to FIG. 12 , a pair of protruding plates or fingers 65 and 66 is seen to extend upwardly from the base 75 of turret 76 , the plates being suitably dimensioned to fit within the groove 41 of edging block 40 . The thickness 77 of each plate 65 and 66 is approximately 0.060 inch. The distance 80 between the outer end 78 of plate 66 and the outer end 79 of the plate 65 is approximately 0.450 inch. The turret 76 also includes an inner wall 81 and an outer wall 71 , the inner wall 81 being formed to include a series of substantially equally spaced columns, such as columns 67 and 68 for example. The columns engage with the edging block surfaces 43 and 44 , for example, to add further stability to the edging block 40 when mounted to the turret 76 . The angular distance 212 between adjacent columns is approximately thirty degrees. The greatest angular distance 83 between the lateral axis 82 of the plate 65 and the farthest adjacent inner wall column 84 is approximately twenty degrees. [0054] As best seen in FIG. 13 , the height 85 of each inner wall column, such as column 96 , for example is approximately 0.145 inch. The clearance 88 between the top surface 86 of the turret 76 and the top surface 87 of the plate 66 is approximately 0.025 inch. The overall length 89 of the elongated collet 22 is approximately three inches. The distance 90 between the base 75 and the top surface 86 of the turret 76 is approximately 0.210 inch. Referring also to FIGS. 14 and 15 , the height 93 of the plate 66 is 0.185 inch. The base width 91 of the plate 66 is approximately 0.060 inch while the plate sidewall taper 92 is approximately four degrees. The cross sectional width 94 of each inner wall column, such as column 97 , for example, is approximately 0.016 inch and the height 95 of column 97 is approximately 0.020 inch. [0055] FIGS. 16, 19 and 20 depict an alternate embodiment 217 of the elongated collet 22 . The turret 218 is formed to include four longitudinal slots 219 , 220 , 221 and 222 . The result is the creation of four individual tangs 223 , 224 , 225 and 226 , the tangs 223 and 224 being deformable in a direction parallel to line 227 while tangs 225 and 226 may be deflected in a direction that is parallel to the line 228 . Sixteen individual columns, such as columns 229 , 230 , 231 and 232 are formed on the inner wall 233 of the turret 218 , arranged symmetrically such that four columns each reside on any individual tang 223 - 226 . Each column protrudes outwardly from the inner wall 223 by a distance 234 of approximately 0.044 inch. [0056] The elongated collet 217 includes a pair of upwardly extending blades 236 and 237 adapted to engage the edging block 40 . The elongated collet 217 permits the application of a greater force to an edging block 40 inserted into the turret 218 , thereby suppressing movement of the edging block with respect to the inner wall 223 during rotation of the elongated collet. Both the elongated collets 22 and 217 are formed of a metallic alloy manufactured by Hardinge, Inc. of Elmira, N.Y. The inner wall 223 may be coated with a diamond film or surface texture in order to further reduce wear caused by differential motion between the collet and the edging block. [0057] Referring to FIGS. 17 and 18 , a modified edging block 40 a is depicted. The edging block 40 a is substantially similar to the edging block 40 disclosed in FIG. 7 , except that the circular perimeter 214 of the edging block 40 a is interrupted by the two parallel sidewalls 215 and 216 , thereby creating a relatively smaller surface area for the edging block 40 a . The geometry of the block 40 a is useful for mounting smaller lenses so as not to interfere with edging tools that may be employed in shaping a smaller lens. The edging block 40 a is mounted on the turret 76 . The central protrusion 49 a of the edging block 40 a fits snugly between the blades 65 and 66 of the turret 76 to create a unified assembly capable of resisting a substantial torsional force. [0058] FIGS. 21 and 22 illustrate the collet closer 238 that grips and rotates the elongated collet 217 . The collet closer 238 operates generally as disclosed in U.S. Pat. No. 5,221,098 entitled “Collet Closer”. The first inlet orifice 240 permits the application of pressure to unclamp the collet 217 , while the second inlet orifice 241 permits the application of pressure to clamp the collet 217 . The bore 239 permits access to a set screw residing in threaded chamber 242 , thereby permitting the collet 217 to be secured within the collet closer 238 . [0059] The calibration lens blank 98 depicted in FIG. 23 is an example of a lens blank that may be manipulated by the combination of the elongated collet 22 and edging block 40 . The calibration lens 98 includes a series of calibration markings such as an alignment cross 99 , vertical lines 100 and 101 , and horizontal lines 102 , 103 , 104 and 105 . A plurality of circles, such as circles 106 , 107 , 108 and 109 , are also formed on the lens blank 98 by means of drawing, etching, engraving, painting or other surface marking techniques. In practice, the line and circle configuration of blank 98 may be varied, but this particular example is illustrative of the basic geometrical features of the present invention. [0060] A second embodiment of a calibration lens blank 110 is illustrated in FIGS. 24, 25 and 26 , showing a lens blank having sixteen circular markings arranged in a pattern with respect to a horizontal axis 112 and a vertical axis 111 . In practice, the lens blank 110 is manufactured in two forms, both of which are geometrically identical. However, one version is composed of polycarbonate, while the other version is made of allyl diglycol carbonate, a plastic polymer commonly referred to as CR39. The polycarbonate material is more difficult to shape using traditional cutting tools, meaning that a version of lens blank 110 would often require different tool pressure settings when being processed by an automated shaping device. In order to verify the proper operation of a highly automated shaping apparatus, both a polycarbonate and a CR39 lens blank 110 are shaped by the same device in order to determine if the cutting tool is properly adapting to each material to produce a substantially identical lens. [0061] The first circular marking 113 on lens blank 110 is placed at a distance 114 of approximately 0.610 inch from the vertical axis 111 and at distance 115 of approximately 0.198 inch from the horizontal axis 112 . The horizontally adjacent second circular marking 117 is spaced at a distance 118 of approximately 0.753 inch from the vertical axis 111 . Vertically offset from the circular markings 113 and 117 is a horizontal row composed of circular markings 120 and 119 . The innermost marking 119 resides at a distance 121 of approximately 0.079 inch from the horizontal axis 112 and at a distance 123 of approximately 0.753 inch from the vertical axis 111 . The outermost marking 120 is placed at a distance 122 of approximately 0.812 inch from the vertical axis 111 . The circular markings 113 and 117 define a first horizontal row, while circular markings 119 and 120 define a second horizontal row. [0062] A third horizontal row of circular markings, residing above the horizontal axis 112 , is defined by the circular markings 124 and 125 . The marking 124 is displaced a distance 126 of approximately 0.079 inch from the horizontal axis 112 and by a distance 127 of approximately 0.871 inch from the vertical axis 111 . Ideally, the distances 121 and 126 are substantially equal. The horizontally adjacent circular marking 125 is displaced by a distance 128 of approximately 0.733 inch from the vertical axis 111 . Markings 124 , 125 , 129 and 130 define a horizontal row that is symmetrically spaced about the vertical axis 111 . The markings 124 , 125 , 129 and 130 indicate that a single type of lens may be fastened on either a right or left side to a spectacle lens frame, for example. This requirement creates the need for calibration marks that are symmetrical about the single vertical axis 111 . A fourth horizontal row is composed of circular markings 131 , 132 , 133 and 134 . Circular marking 131 is displaced a distance 135 from the vertical axis 111 by approximately 0.931 inch. The marking 132 is displaced from the vertical axis 111 by a distance 136 of approximately 0.792 inch. Each of the markings 131 , 132 , 133 and 134 is displaced from the horizontal axis 112 by a distance 137 of approximately 0.198 inch. The circular markings 113 , 119 , 125 and 132 form one of four diagonal rows appearing on the calibration lens 110 . The four rows of circular markings permit four successive uses of the calibration lens 110 , moving inwardly from the outermost hole 131 to the innermost hole 113 . [0063] The calibrations lens 110 includes four pairs of horizontal linear markings. The first pair of linear markings is composed of lines 138 and 139 which are spaced apart by a distance 140 of approximately 1.969 inch. The second, adjacent pair of linear markings includes lines 141 and 142 which are separated by a distance 143 of approximately 1.732 inch. The third adjacent pair of linear markings consists of horizontal lines 144 and 145 , spaced apart by a distance 146 of approximately 1.309 inch. The innermost pair of horizontal linear markings is formed by lines 147 and 148 which are separated by a distance 149 of approximately 1.084 inch. The four pairs of horizontal lines permit the calibration lens 110 to be used four separate times, that is, as material is successively removed during the edging process, the line 138 is initially consumed, the second edging pass references line 141 , the third edging pass utilizes line 144 , and finally the only reference line remaining for use is the line 147 . [0064] Three pairs of vertical linear markings are formed on calibration lens 110 . The outermost pair of vertical linear markings is composed of lines 150 and 151 , separated by a distance 152 of approximately 1.969 inch. The lines 150 and 151 extend vertically so as to terminate at the perimeter 154 of the lens 110 , where they join the horizontal lines 138 and 139 . A second pair of vertical linear markings includes vertical lines 153 and 155 , each of which terminates at the horizontal lines 141 and 142 . The spacing 156 between lines 153 and 155 is approximately 1.732 inch. A third pair of vertical linear markings consists of vertical lines 157 and 158 , which each have a lower end that is spaced a distance 159 of approximately 0.398 inch from the horizontal axis 112 . [0065] The upper ends of the lines 157 and 158 reside at a distance 160 from the horizontal axis 112 of approximately 1.043 inch. The parallel vertical lines 157 and 158 are spaced apart from each other by a distance 161 of approximately 1.335 inch. As best seen in FIG. 18 , the outer radius 162 of the lens 110 is approximately 3.497 inches, the lens 110 having a thickness 163 of approximately 0.087 inch. The overall distance 166 between the top surface 164 and the bottom surface 165 is approximately 2.812 inches. The central region of the calibration lens 110 is best viewed in FIG. 26 , which includes a tee 167 which is formed to have a horizontal section 168 that has a length 169 of approximately 0.158 inch. The lower tip 170 of tee 167 is spaced apart from the horizontal axis 112 by a distance 171 of approximately 0.039 inch. Horizontal section 168 is displaced from the horizontal axis 112 by a distance 172 of approximately 0.157 inch. A pair of horizontal linear markings 174 and 175 overlay the horizontal axis 112 . The end 176 of the horizontal marking 174 is offset from the vertical axis 111 by a distance 173 of approximately 0.039 inch. [0066] The vertical and horizontal lines just described define rectangles that replicate two types of machine calibration standards commonly used in the spectacle lens industry. The first calibration standard is used in association with equipment manufactured by National Optronics, 100 Avon Street, Charlottesville, Va., while the second standard is a development of Precision Tool Technologies, 924 Wright Street, Brainerd, Minn. [0067] FIG. 27 depicts an example of a machine calibration standard device 197 , which is formed to include two exemplary lens shape cutouts or pockets 198 and 199 having a specific geometry and dimensions. The overall width 200 of the standard device 197 is approximately five inches, while the overall height 203 is approximately two inches. The distance 201 between the left edge 207 of the standard device and the left edge 209 of lens pocket 199 is approximately 2.972 inches. The distance 202 between left edge 207 and the left edge 208 of the lens pocket 198 is approximately 0.261 inch. The height 204 of the lens pocket 199 is approximately 1.0977 inches, while the width 206 of the lens pocket 199 is approximately 1.767 inches. The radius 205 of each corner 210 is approximately 0.375 inch. [0068] The geometry and dimensions of each lens pocket 198 and 199 are identical. Each lens pocket defines an internal circumference 211 which extends continuously around each pocket 198 and 199 . In practice, a stylus, feeler gauge or other sensor travels along the circumference 211 to define the shape and size of a lens which is to be formed by a cutting or edging device associated with the sensor. In this manner the particular geometry of the pocket 198 , for example, is transferred to the edging device and is typically accessible to an operator of the edging device via a graphical user interface or other convenient means. The machine operator is then free to generate a drawing or display which indicates the desired configuration of a finished lens which may then be compared to the lens blank 98 . [0069] FIG. 28 illustrates the use of the lens blank 98 that is depicted in FIG. 23 . A lens 178 is shown that results from an edging process performed on the blank 98 . In other words, only the lens 178 remains after machining blank 98 , so all of the material residing outside of the closed boundary defined by lines 177 , 180 , 193 and 179 would no longer be present. Although a substantial portion of the surface area of the blank 98 has been discarded, the remaining data present regarding the quality of the lens 178 is sufficient to indicate a miscalibration of the edging tool. The horizontal lines 194 and 195 are no longer present, but the horizontal line segments 104 , 105 and 243 remain and are sufficient to readily indicate that the lens 178 is tilted with respect to the horizontal axis of the lens blank 98 . While only a portion of the horizontal line segment 103 is present on the lens 178 , a somewhat smaller part of the symmetrically positioned line segment 106 is visible. Vertical line 244 is slightly visible, while vertical line is not visible. This geometry indicates that lens 178 is off center. A hole 183 has been drilled in the lens 178 , but overlaps the circular marking 182 , indicating that the hole 183 has not been drilled in its desired location. The symmetrically placed circular marking 196 does not show any sign of a drilling operation, further indicating a substantial misalignment of the edging machine that performed the machining operations on the blank 98 . [0070] Referring also to FIG. 29 , the lens blank 110 illustrated in FIG. 24 is shown after being formed into a completed lens. In other words, the portion of blank 110 appearing in FIG. 24 but absent in FIG. 29 has been removed during the machining operation that formed the completed lens. The proper formation of the lens is apparent by observing that the vertical marking 153 is parallel to lens edge 185 , while lens edge 187 is parallel to vertical marking 155 . Similarly, horizontal lens edges 184 and 186 are parallel to horizontal markings 191 and 192 . The drilling operations also appear to be correct based on the presence of drilled bore 189 residing entirely within the circular marking 113 . A corresponding bore 190 appears within the boundary defined by the symmetrically spaced circular marking 188 . These correlations indicate that the edging device that removed material from the lens blank 110 has been properly calibrated and is performing as desired. [0071] The foregoing features embodied in the present invention are by way of example only. Those skilled in the lens manufacturing field will appreciate that the foregoing features may be modified as appropriate for various specific applications without departing from the scope of the claims. For example, the dimensions and shape of the collet 22 may be varied to accommodate a particular deblocking machine. Further, the position and number of blades 65 and 66 may be adjusted to accommodate a particular edging block 40 . Further, the calibration lenses 98 and 110 may have different shapes and dimensions that those depicted, and the surface markings may be varied as required for a particular lens design.

A lens processing system used for removing a lens blank ( 98, 110 ) from an edging block ( 40 ). The system includes an elongated collet ( 22 ) that engages the mating edging block ( 40 ). The block ( 40 ) includes an enlarged groove ( 41 ) that receives a pair of blades ( 65, 66 ) extended upwardly from the floor ( 75 ) of the collet ( 22 ). Each lens blank ( 98,110 ) is formed to include a series of surface markings ( 191,192 ) to verify proper functioning of the edging machine that forms a finished lens. Each lens blank also includes a series of circular markings ( 117,133 ) arranged in diagonal rows to verify the accurate drilling of bores with the lens blank ( 98,110 ).

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to vehicle brake lights and, more particularly, to vehicle brake lights having a plurality of lights with the lights illuminating in response to the degree of brake application pressure. 2. Description of the Prior Art U.S. Pat. No. 4,682,146 (Friedman) discloses an indicator light system using a horizontally disposed tube filled with a rare gas. The gas tube is connected to turn signal indicators and the light in the tube propagates from either the left hand side of the tube or the right hand side of the tube, depending on the direction of travel of the vehicle. For a left hand turn, the light propagates from the right hand side progressively to the left hand side, indicating a left turn. For a right turn, the opposite happens. That is, the light propagates from the left side progressively to the right side. The apparatus is not degree-based responsive. U.S. Pat. No. 5,606,310 (Egger et al) discloses a safety system in which a pair of lights illuminate when hard braking pressure is applied. A pressure transducer is used to sense the pressure of the brake pedal application. The system is coupled to the ordinary brake light system to provide different light effects depending on brake pressure applied. However, the light effects could be mistaken as a hazard warning light function. U.S. Pat. No. 5,610,578 (Gilmore) discloses a light system indicative of pressure application on the brake system. Deceleration is sensed as well as brake pressure application. The brake illumination system provides brake light intensity as a function of the deceleration of the vehicle. The motion of the brake arm during braking is used as a determining element. This apparatus, like the '310 (Egger) apparatus, utilizes the brake lights in an ordinary brake light system circuit. No additional lights or light elements are used. The apparatus is dependent on ambient conditions and bulb life to indicate intensity. Its is unclear how light intensity is translated into vehicle deceleration. U.S. Pat. No. 5,682,137 (Li) discloses a safety system for vehicles which indicates acceleration and deceleration of the vehicle. The system utilizes inertial forces to determine acceleration and deceleration and sequentially activates lights in response to acceleration and deceleration. Red lights are used in response to deceleration, and green lights are used in response to acceleration. It will be noted that a problem with this system is that changes in the attitude of the vehicle will also cause changes of the sensitivity of the apparatus. That is, going uphill or going downhill which changes the attitude of the vehicle, will result false indications of acceleration or deceleration. The apparatus is also sensitive to vehicle loading changes which affect the attitude of the vehicle. U.S. Pat. No. 5,831,523 (Lange) discloses a vehicle light system which uses a plurality of spaced apart light emitting diodes disposed about the rear window. Both red and yellow L.E.D.s are used with yellow L.E.D.s used as an adjunct to the directional indicators and red L.E.D.s tied into the brake system. The red L.E.D.s are activated when the brake light system is activated. The lights actuate sequentially, not in response to brake pressure. The red lights actuate sequentially as an indication that the brakes have been actuated, but they are not indicative of brake pressure. That is, the apparatus is independent of brake application intensity. The red L.E.D.s illuminate sequentially from the top center of the rear window outwardly and downwardly on the sides of the window. The apparatus of the present invention utilizes red L.E.D.s or high intensity lamps or the like which illuminate sequentially in response to intensity of brake application pressure. That is, a ladder-effect of the red L.E.D.s occurs in direct response to brake pressure. Two embodiments are included, the first being an original equipment type installation and the second being an after market installation. SUMMARY OF THE INVENTION The invention described and claimed herein comprises a brake light system in which appropriate red lamps or L.E.D.s are sequentially illuminated in response to brake pressure application. The lamps are arranged in a ladder-like configuration and they illuminate successively in response to brake pressure. The brake light of the standard brake circuit is tied into the lamps. Two different types of sensors are used, one is a simple potentiometer responsive to movement of the brake pedal for original equipment installation and the second is an after market application in which a strain gauge sensor is used to sense brake pressure. The strain gauge sensor is tied to a flexible brake line, and the expansion of the brake line in response to increased brake pressure is used to cause an output in the strain gauge sensor. Among the objects of the present invention are the following: To provide new and useful brake light apparatus; To provide new and useful brake light apparatus having a plurality of red lamps; To provide new and useful apparatus for indicating braking in a vehicle; To provide new and useful apparatus indicating the intensity of brake pressure applied to a vehicle utilizing a plurality of red lamps; To provide new and useful indicators of the intensity of application of brake pressure in a vehicle; and To provide new and useful apparatus for sensing and indicating brake pressure application in a vehicle. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic diagram of the apparatus of the present invention. FIG. 2 is a side view schematically representing sensing apparatus usable with the apparatus of FIG. 1 . FIG. 3 is a view in partial section illustrating sensing apparatus usable with the apparatus of FIG. 1 . DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 comprises a schematic circuit diagram of brake pressure intensity indication system 10 of the present invention. FIG. 1 includes three blocks, including a brake system measurement block 12 , a zero and gain amplifier block 42 , and an analog to progressive digital converter block 48 . A conductor 14 extends from brake system measurement block 12 to a conductor 16 . The brake system measurement block 12 is also connected to the zero and gain amplifier block 42 by a conductor 40 . The amplifier 42 is connected to the conductor 14 by a conductor 44 . The amplifier 42 is connected to the converter 48 by a conductor 46 , and the converter 48 is connected to the conductor 14 by a conductor 50 . The conductor 14 extends to a conductor 16 which extends to a conductor 18 . The conductor 18 extends through a brake switch 20 to a twelve volt power source 22 . The switch 20 is a brake light switch associated with the brake pedal of a vehicle. Thus, when the brake is applied, the switch 20 closes, and the twelve volt current source 22 is then connected to the conductor 18 and through the conductors 16 , 14 , 44 , and 50 to the three blocks 12 , 42 , and 48 . A conductor 24 extends through a brake light 26 , and from the brake light 26 a conductor 28 extends to the vehicle ground 30 . A conductor 32 extends from the conductor 24 to the “other” vehicle brake light. It will be recognized that the twelve volt current source 22 , the brake light switch 20 , and the conductors 18 , 24 , lamp 26 , conductor 32 and ground 30 comprise the typical brake light circuitry. However, in the present invention, the conductor 18 also extends to provide electrical power to the brake measurement system 12 through the conductors 16 and 14 . The brake measurement system 12 provides an output on conductor 40 in response to the intensity of the brake pressure application. The output of the brake system measurement block 12 on conductor 40 is transmitted to the zero and gain amplifier 42 which in turn amplifies the signal and provides its output signal on conductor 46 to the analog to progressive digital converter block 48 . The analog to progressive digital converter system 48 in turn provides outputs on conductors to an array of lamps or L.E.D.s. It will be noted that in FIG. 1 , L.E.D.s are indicated, 5 but it will be understood that any appropriate lamp may be used. The result is a ladder of lights, the numerically progressive illumination of which is indicative of the intensity of the brake pressure application. Four levels of brake pressure indication are illustrated with eight conductors and lamps extending from the block 28 . For example, there are typically two brake lights on a vehicle. Conductors 60 and 64 extend from the block 28 to a pair of L.E.D.s 62 and 66 , respectively, which may illuminate as a conventional third brake light. Conductors 68 and 72 extend from the block 48 to a pair of L.E.D.s 70 and 74 , respectively, which, when illuminated, provide an indication of relatively low brake pressure intensity. Conductors 76 and 80 , which extend from the block 28 to a pair of L.E.D.s 78 and 82 , respectively, illuminate in response to a moderate intensity of brake pressure application. Conductors 84 and 88 extend from the block 28 to a pair of L.E.D.s 86 and 90 , respectively, and the illumination of L.E.D.s 86 and 90 then indicate a high intensity of brake pressure application. The respective L.E.D.s remain illuminated until the brake pressure is removed, thus providing a vivid visual indication of brake pressure intensity. Obviously, there may be as many L.E.D.s utilized as desired. For example, the eight L.E.D.s illustrated may be configured in low vertical arrays, or ladders, on opposite sides of the rear window of a vehicle. An alternative may be to utilize the eight L.E.D.s as a single array on one side of the rear window and provide an additional eight in parallel on the opposite side of the rear window. FIG. 2 comprises a schematic representation of the sensor elements usable with the apparatus of the present invention. There is shown the brake system measurement block 12 which includes within it a potentiometer, and an arm 110 is coupled to the potentiometer within the block 12 . The block 12 is appropriately secured to part of the vehicle chassis 2 . Also secured to a portion of the vehicle chassis 2 , as is known and understood, is a brake arm 114 to which is secured a brake pedal 112 . The elements involved with the brake pedal 112 and its arm 114 have been omitted for purposes of clarity with respect to the present invention. Depressing the brake pedal 112 causes movement of the brake arm 114 , and with it is movement of the actuating arm 110 of the potentiometer within the block 12 . The intensity of the pressure applied to the brake is, of course, measured by the movement of the brake arm 114 , and accordingly of the actuating arm 110 . The output of the potentiometer within the block 12 then provides the output as discussed above with respect to FIG. 1 and the blocks 42 and 48 to the L.E.D. array. An alternate sensor system, as an after market application, is illustrated in FIG. 3 . FIG. 3 illustrates, in partial section, sensor elements associated with a brake hose 160 for providing an output for the block 12 as illustrated in FIG. 1 and discussed above. In FIG. 3 , a clamp unit 130 is shown disposed about the brake hose 160 . The clamp unit 130 includes a bottom plate 132 , with a pillow 134 extending upwardly from the bottom plate. The hose 160 is clamped on the pillow 134 . A top plate 140 is spaced apart from the bottom plate 132 by a pair of posts 136 and 138 . The posts 136 and 138 are secured to the bottom plate 132 and the top plate 140 by bolts 150 and 154 and their respective nuts 152 and 156 . The top plate 140 includes a recess 142 in which is disposed a strain gauge sensor 144 . A conductor 146 extends from the strain gauge sensor 144 to provide an output responsive to the brake pressure applied. The conductor 146 extends to the brake system block 12 . The brake pressure applied will cause an expansion of the brake hose 160 . The expansion of the brake hose 160 is indicative of the intensity of the brake pressure applied. Accordingly, the output of the strain gauge sensor 144 will also be responsive to the intensity of the applied brake pressure. Returning again to FIG. 1 , when the switch 20 is closed, indicating that the brake pedal has been pushed, the vehicle brake lights, such as the lamp 26 and the second lamp, not shown, but provided with current from conductors 18 , 24 , and 32 , the L.E.D.s 62 and 66 will also be illuminated. Depending on the intensity of the brake pedal application, additional pairs of L.E.D.s in the array will also be illuminated. Maximum intensity will illuminate all of the L.E.D.s in the array. A pair of such L.E.D. arrays as illustrated in FIG. 1 , and parallel with each other, and disposed on opposite sides of the rear window, for example, will provide a very noticeable indication to following drivers of the intensity of the brake application by the driver of the vehicle employing the apparatus 10 . It will be understood that there may be as many L.E.D.s in an array as desired, or as practical for any particular illustration. The L.E.D.s in the array of FIG. 1 are merely illustrative. While the principles of the invention have been made clear in illustrative embodiments, there will be immediately obvious to those skilled in the art many modifications of structure, arrangement, proportions, the elements, materials, and components used in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements without departing from those principles. The appended claims are intended to cover and embrace any and all such modifications, within the limits only of the true spirit and scope of the invention.

Brake pressure indication apparatus in a vehicle includes a plurality of red L.E.D.s arranged in a ladder-like configuration. The L.E.D.s illuminate progressively in response to brake pressure. As brake pressure is increased, more L.E.D.s illuminate. Brake pressure may be sensed in either of two ways, such as movement of the brake pedal or the expansion of a flexible brake hose.

This application claims benefit to Provisional Application No. 60/087,591 filed Jun. 6, 1998. FIELD OF THE INVENTION This invention relates to interleaving and is particularly concerned with interleaving systems and methods suited for Turbo and Turbo-like forward-error-correcting codes, by using golden section increments. BACKGROUND OF THE INVENTION Interleaving is a key component of many digital communications systems involving forward error correction (FEC) coding. This is especially true for channels characterized by fading, multipath, and impulse noise, for example. A second example is the class of magnetic recording channels where bursts of errors are caused by defects in the recording media. Interleaving, or permuting, of the transmitted elements, provides time diversity for the FEC scheme being employed. An element is used herein to refer to any symbol, sample, digit, or a binary digit (bit). Interleaving spreads out the corrupted portions of the signal and makes it easier for the FEC scheme to correct the associated errors. Conventionally, the interleaving strategy is only weakly linked to the FEC scheme being employed. An exception is the case of concatenated FEC schemes using concatenated Viterbi and Reed-Solomon decoders. The interleaver is placed between the two FEC encoders to help spread out error bursts and the depth of interleaving is directly linked to the error correction capability of the inner (Viterbi) decoder. More recently, however, interleavers have become a more integral part of the coding and decoding strategy itself. Such is the case for Turbo and Turbo-like codes, where the interleaver forms an integral part of the coding scheme. The problem of finding optimal interleavers for such schemes is really a code design problem, and is an on-going area of research. Claude Berrou obtained U.S. Pat. No. 4,446,747 entitled: “Error-correction coding method with at least two systematic convolutional codings in parallel, corresponding iterative decoding method, decoding module and decoder”. This patent describes essentially the same Turbo-code presented by Berrou et al. in their paper “Near Shannon Limit Error-Correcting Coding and Decoding: Turbo-Codes”, published in the Proceedings of ICC'93, Geneva, Switzerland, pp. 1064-1070, May, 1993. The Turbo code presented, is a rate ½ binary code that provided performance within 0.5 dB of the BPSK capacity limit at a BER of 10 −5 , when using an interleaver block size of 65,536. This result is also only 0.7 dB from the more general Shannon capacity limit. The encoder consists of two rate ½ recursive systematic convolutional (RSC) encoders operating in parallel with the information binary digits (bits) interleaved between the two encoders as shown in FIG. 1 . Without puncturing, and with rate ½ constituent codes, the overall code rate is ⅓. This is because the systematic information bits only need to be sent once. Other code rates can be achieved as required by puncturing the parity bits c 1 k and c 2 k . In this configuration, the job of the interleaver is to spread error bursts that occur in one code throughout the other code so that there is a higher probability of correcting unreliable information. More recently Berrou, and Glavieux provided more discussion of the coding and decoding of Turbo codes in their paper “Near Optimum Error Correcting Coding and Decoding: Turbo-Codes”, published in the IEEE Trans. on Conm., Vol. 44, No. 10, October 1996. FIG. 2 illustrates one approach to Turbo decoding, based on maximum a posteriori (MAP) decoding algorithm derived by Bahl et al their paper “Optimal Decoding of Linear Codes for Minimizing Symbol Error Rate”, published in IEEE Trans. on Inform. Theory, Vol. IT-20, pp. 284-287, March 1974. The MAP decoder is implemented in the log domain, so the log-MAP algorithm is used. The Turbo decoder uses an iterative process where the de-interleaved output vector of the second log-MAP decoder L 2 , is fed back to the input of the first log-MAP decoder after the first iteration. The storage vector to the second log-MAP decoder must be interleaved using the same interleaver used in the Turbo encoder. Likewise, the output from the second log-MAP decoder must be de-interleaved before being fed back to the input of the first log-MAP decoder. Decisions can be made either at the output of the first log-MAP decoder or the de-interleaved output of the second log-MAP decoder. It is the convention that one Turbo decoding iteration be defined as two log-MAP decoding operations as shown in FIG. 2 . Interleaving is a key component of any Turbo encoder and decoder, as already shown in FIGS. 1 and 2. Although some form of random or pseudo-random interleaving is usually recommended for Turbo-codes, it has been found that simple structured interleavers can also offer excellent performance, especially for short data blocks on the order of a few hundred bits. Examples of structured prior art interleavers include relative prime interleavers, convolutional interleavers, helical interleaver and L×M matrix (or block) interleavers using L rows and M columns. L×M matrix interleavers are usually implemented by writing into the rows and reading out of the columns, or vice versa. The rows and/or columns are sometimes read in and/or out in a permuted order. This permuted order is often implemented using a relative prime number. That is, the row or column index can be generated using modulo arithmetic where the index increment and row or column lengths are relative prime numbers. With L or M equal to 1, this type of interleaver simply becomes a one-dimensional relative prime interleaver. In U.S. Pat. No. 5,056,105, Darmon et al refer to relative prime interleavers which seem to offer some advantages over conventional L×M matrix interleavers. In a relative prime interleaver, the n'th digit (element) of the interleaved vector is read out of the original vector using the index s+np, modulo N, where s is an integer starting index and p is an integer index increment. The starting index s is usually set to 0 but can be any index. The increment p must be relative prime to the block size N to ensure that each element is read out once and only once. One problem with prior art interleavers is that they are usually designed to provide a specific interleaving depth. This is fine if each burst of errors never exceeds the interleaver depth, but it is wasteful if the interleaver is over-designed (too long) and error bursts are much shorter than the interleaver depth. For example, a simple 10×10 matrix interleaver has an interleaving depth of 10 elements. If a burst of 10 errors occurs, the de-interleaver will optimally spread these 10 errors throughout the block of 100 elements. If the error burst is 11 elements long, however, then two errors will again be adjacent. If the error burst is only 2-elements long then these 2 errors will only be spaced 10 elements apart after de-interleaving, but they could have been spaced much farther apart if it was known that only two errors were present. For example, a 2×50 matrix interleaver would have spaced these two errors 50 elements apart. Of course this interleaver is not good for longer bursts of errors. In practice, most channels usually generate error events of random length, and the average length can be time varying, as well as unknown. This makes it very difficult to design optimum interleaving strategies using the above-mentioned prior art methods. It is also desirable for an interleaving strategy for Turbo-codes to spread “error bursts” from one component decoder throughout the data block for the other component decoder. One measure of how good a particular burst of elements has been spread by an interleaver is the minimum difference between the interleaved indexes of the original burst of elements considered. The problem is that error bursts can start anywhere and are random in length. The best interleaver for one burst length is not necessarily the best interleaver for another burst length. What is sought is an interleaving strategy that is good for any error burst length. SUMMARY OF THE INVENTION An object of this invention is to provide an improved interleaver with a tendency to maximally spread the error-bursts generated by an error-burst channel or decoder, independent of the error-burst length. It is another object of this invention to use golden section increments to achieve desirable spreading properties. In addressing these objects, the invention makes use of the golden section, which is easy to compute for any block size, and is unique for that block size. In other words, the block size uniquely defines a golden section increment in accordance with this invention, without having to perform a time consuming search for the best increment value. A number of interleaver embodiments, based on this golden section increment, are provided by this invention. The term interleaver is also used to refer to a de-interleaver. With this invention, there is no concept of interleaver depth and no need to design the interleaver for a particular channel type or for a worst case error-burst length. For Turbo-codes it is also beneficial to obtain good spreading for elements r apart, where r is the repetition period of the feedback polynomial in the RSC encoder, as well as for adjacent elements. As an example, a good binary, rate ½, RSC encoder has a repetition period of r=2 m −1, where k and m=k−1 are the constraint length and memory, respectively, of the RSC encoder. In accordance with an aspect of this invention there is provided an interleaving system for rearranging a stream of N input elements into a stream of N output elements, said interleaving system comprising: (a) an element memory; (b) an indexer for generating a sequence of input indexes and a sequence of output indexes, wherein at least one of said sequences of indexes is defined in terms of a golden section g equal to ({square root over (5−1)})/2; (c) an input module coupled to said indexer for writing said stream of N input elements into said element memory according to said sequence of input indexes; and (d) an output module coupled to said indexer for reading said stream of N output element from said element memory according to said sequence of output indexes. The interleaving system can further comprise an index memory for storing a sequence of index offsets corresponding to the at least one of said sequences of indexes. Alternatively, the indexer comprises an index memory for storing the at least one of said sequences of indexes. Another alternative is for the indexer to comprise: (i) an index memory for storing a sequence of input index offsets; and (ii) a nominal index generator coupled to said index memory for generating a sequence of nominal input indexes; wherein the indexer generates the sequence of input indexes by adding said sequence of input index offsets to said sequence of nominal input indexes. Yet another alternative is for the indexer to comprise: (i) an index memory for storing a sequence of output index offsets; (ii) a nominal index generator coupled to said index memory for generating a sequence of nominal output indexes; wherein the indexer generates the sequence of output indexes by adding said sequence of output index offsets to said sequence of nominal output indexes. In a first embodiment of this invention, a golden relative prime interleaver is provided wherein the indexer generates the at least one of said sequences of indexes as a sequence i with elements defined as i(n)=s+np, modulo N, where s is a pre-selected integer starting index, p is an integer index increment which is prime relative to N, defined in terms of g, and n is an integer progressively rising from 0 to N−1. The indexer gives p a value close to a real value c=N(g m +j)/r, where m is a pre-selected non-zero integer, r is a non-zero integer defining a distance between any pair of input elements that are to be maximally spread, and j is a pre-selected integer modulo r. In determining the value of p, one approach is to round p to one of a pair of values immediately above and below c. Alternatively, the value of p is selected to maximize a minimum difference between pairs of interleaver indexes within i up to a pre-selected maximum number of elements. Yet another approach is to select the value of p so as to maximize a weighted sum of minimum differences between pairs of interleaver indexes within i for all numbers of elements from 2 up to a pre-selected maximum number of elements. Preferably, r=1, j=0 and m is a non-zero integer having an absolute value less than 10. It is also preferred to have one sequence of said sequences of indexes to rise from zero to N−1 by an index increment of 1. The golden relative prime interleavers are particularly attractive because they are simple to implement and require little or no additional processing and memory, compared to no interleaving. In a second embodiment of this invention, a golden vector interleaver is provided, wherein the indexer comprises: (i) a vector generator for generating a golden vector v with elements defined as v(n)=s+nc, modulo N, where s is a pre-selected real starting value, c is a real increment value defined in terms of g, and n is an integer progressively rising from 0 to N−1; (ii) sorting means responsive to said vector generator for finding a sort vector z determined from a(n)=v(z(n)), for n=0 . . . N−1, where a contains the elements of v sorted in one of rising and descending orders; and (iii) assigning means responsive to said sorting means for assigning the at least one of said sequences of indexes i with elements defined by one of i(n)=z(n) and i(z(n))=n, for n=0 . . . N−1. In one aspect of this second embodiment, a dithered golden vector interleaver is provided, wherein the vector generator uses a dither vector d with an n'th real dithering component d(n) of a prescribed distribution D for generating said golden vector such that v(n)=s+nc+d(n), modulo N. Preferably, c=N(g m +j)/r, where m is a pre-selected non-zero integer, r is a non-zero integer defining a distance between any pair of input elements that are to be maximally spread, and j is a pre-selected integer modulo r. Alternatively, the value of c is rounded to one of a pair of integer values immediately above and below the real value of N(g m +j)/r. Preferably, r=1,j=0 and m is a non-zero integer having an absolute value less than 10. It is also preferred to have one of said sequences of indexes rise from zero to N−1 by an index increment of 1. The dithered golden vector interleaver has the desirable spreading properties of the golden vector interleaver, but also has the randomness found beneficial for Turbo-codes. In a practical embodiment of this invention, at least one interleaving system forms part of a tail-biting Turbo-code encoder comprising a plurality of tail-biting systematic convolutional encoders operating in parallel, wherein each of said at least one interleaving system is positioned at an input of at least one of said plurality of tail-biting systematic convolutional encoders. In another practical embodiment of this invention, at least one interleaving system forms part of a Turbo-code encoder comprising a plurality of systematic convolutional encoders operating in parallel, wherein each of said at least one interleaving system is positioned at an input of at least one of said plurality of systematic convolutional encoders. In another aspect of the present invention, there is provided an interleaving method for rearranging a stream of N input elements into a stream of N output elements, said interleaving method comprising the steps of: (a) generating a sequence of input indexes and a sequence of output indexes, wherein at least one of said sequences of indexes is defined in terms of a golden section g equal to ({square root over (5−1)})/2; (b) writing said stream of N input elements into an element memory according to said sequence of input indexes; and (c) reading said stream of N output element from said element memory according to said sequence of output indexes. Alternative embodiments of this method are provided bearing similar limitations as those provided for the interleaving system defined above. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments of the invention will now be further described with references to the drawings in which same reference numerals designate similar parts throughout the figures thereof, and wherein: FIG. 1 illustrates, in a block diagram, a Turbo-code encoder using two RSC codes with puncturing according to prior art; FIG. 2 illustrates, in a block diagram, a Turbo-code decoder using two log-MAP component decoders according to prior art; FIG. 3 gives an illustration of the golden section principle; FIG. 4 illustrates, in a block diagram, an interleaver (or a de-interleaver) where the input and output indexes are generated in terms of the golden section value g, in accordance with a first embodiment of this invention; FIG. 5 illustrates, in a block diagram, an interleaver (or a de-interleaver) where the input and output indexes are generated in terms of the golden section value g, and index offsets stored in memory, in accordance with a second embodiment of this invention; FIG. 6 illustrates, in a flow diagram, a method used to generate the indexes for a golden relative prime interleaver embodiment based on the interleaver shown in FIG. 4; FIG. 7 illustrates, in a flow diagram, a method used to generate the indexes for a golden vector interleaver embodiment based on the interleaver shown in FIG. 5; FIG. 8 illustrates, in a flow diagram, a method used to generate the indexes for a dithered golden vector interleaver embodiment based on the interleaver shown in FIG. 5; FIG. 9 shows in a graph minimum distances between points versus number of points with a golden section increment, as shown in FIG. 3; FIG. 10 shows in a graph minimum differences between interleaver indexes versus number of elements considered with a golden relative prime interleaver, as shown in FIG. 6, where N=1028, p=393, area under curve=4620; and FIG. 11 shows in a graph minimum differences between interleaver indexes versus number of elements considered with a golden vector interleaver, as shown in FIG. 6, where N=1028, area under curve=5250. DESCRIPTION OF THE INVENTION The golden section arises in many interesting mathematical problems. FIG. 3 illustrates the golden section principle in relation to the interleaving problem of interest. The term interleaving is also used herein to refer to de-interleaving. Given a line segment of length l, the problem is to divide it into a long segment of length g and a shorter segment of length 1−g, such that the ratio of the longer segment to the entire segment is the same as the ratio of the shorter segment to the longer segment. That is, g 1 = 1 - g g ( 1 ) Solving this simple quadratic equation for g gives the golden section value g = 5 - 1 2 ≈ 0.618 ( 2 ) Now consider points generated by starting at 0 and adding increments of g, using modulo-1 arithmetic. After the first increment there are two points at 0 and g that are 1−g apart, using modulo-1 arithmetic. Modulo distances are used to allow for the option of having the first point start anywhere along the line segment. From equation (1), the distance of 1−g is the same as g 2 . After the second increment the first and third points determine the minimum distance and this distance is g 3 . Again, this follows from the definition of g in equation (1). After the third increment the first and fourth points determined the minimum distance and this distance is g 4 . The minimum distance after the fifth point is the same. The minimum distance after the sixth point is g 5 . This trend continues, with the minimum distance never decreasing by more than a factor of g when it does decrease. This property follows directly from the definition of the golden section as provided in equation (1). The same distances can also be generated with the complement increment of (1−g)=g 2 ≈0.382. Higher powers of g can also be used for the increment value, but the initial minimum distances are reduced to the smaller increment value. FIG. 9 shows a plot of minimum distances versus the number of points considered, as points are added using an increment of g with modulo-1 arithmetic. FIG. 9 also shows an upper bound for each specific number of points. That is, given n points, but only n points, they could be uniformly spaced with a minimum distance of 1/n. Of course, the golden section increment results are valid for all numbers of points at the same time. The upper bound is not. Even so, the golden section increment results are seen to track the upper bound quite closely. Note that even when the minimum distance drops, most points will still be at the previous minimum distance from their neighbours, with the average distance between points equal to the upper bound. The properties illustrated in FIG. 9 are desirable for interleavers in general, but in particular are desirable for Turbo-code interleavers. It is now shown how this property of the golden section increment can be used in practical interleavers according to alternative embodiments of this invention. FIG. 4 illustrates, in a block diagram, an interleaving system (also called an interleaver) using golden section increments, in accordance with a first embodiment of this invention. The same system is alternatively useable for de-interleaving, as will be evident from the discussion further below. In the first embodiment, a stream of N input elements s in is received by input means, in this embodiment input module 1 , which is coupled to an element memory 2 and an index generator 4 (also called an indexer). The input module writes this stream s in into a storage vector x, which is stored into the element memory 2 , using a sequence of interleaving input indexes i in . Output means, in this embodiment output module 3 , is also coupled to memory 2 and the indexer 4 . The output module 3 reads out a stream of interleaved elements s out from the storage vector x using the sequence of output indexes i out . The indexer 4 generates interleaving index sequences i in and i out , at least one of which is generated in terms of a golden section value g, calculated as g=({square root over (5−1)})/2. In this particular embodiment, the sequence of input indexes i n is generated in terms of g, whereas the sequence of output indexes i out is generated using an increment of 1; that is the storage vector x is read out sequentially. However, in an alternative embodiment of the present invention, the sequence of output indexes i out is generated in terms of g, whereas the sequence of input indexes i in is generated using an increment of 1; that is the storage vector x is read in sequentially. In yet another alternative embodiment of the invention, both i in and i out are generated in terms of g, and are possibly time varying from one input stream to another input stream. In one example, the input indexes for a subsequent input sequence take on the values of the output indexes for the previous output sequence, to facilitate immediate reuse of the storage vector x, on an element-by-element basis, thereby reducing the storage requirement. FIG. 5 illustrates, in a block diagram, an interleaving system using golden section increments, in accordance with a second embodiment of this invention. The same system is alternatively useable for de-interleaving, as will be evident from the discussion further below. In the second embodiment, the interleaver has a similar structure, and operates in a similar way, to that of the first embodiment as shown in FIG. 4, but with the addition of an index memory 5 that stores sequences of interleaver index offsets, o in and o out and inputs them to the indexer 4 . The indexer 4 is still required to generate nominal input and output indexes, using simple calculations, to which the index offsets are added to calculate i in and i out . Index offsets are stored instead of full indexes to save memory. This is explained in more detail below. The interleaving system shown on FIG. 5 is used to implement golden vector as well as dithered golden vector interleaver embodiments, described in more detail below. FIGS. 4 and 5 also represent de-interleavers. The de-interleaver corresponding to a specific interleaver can be implemented in a number of alternative embodiments. For example, the de-interleaver can be implemented using the same index sequences, i in and i out , but where the values of i in and i out are swapped. In one embodiment the interleaver inputs s in into the element memory 2 using write index sequence i in , calculated using an index increment of 1, and outputs s out from the element memory 2 using read index sequence i out , calculated in terms of golden section value g. The corresponding de-interleaver uses indexes k in =i out for writing its inputs and uses indexes k out =i in for reading its outputs. Alternatively, the de-interleaver inputs using k in =i in and uses the appropriate de-interleaving index sequence k out , which undoes the interleaving process. In this case, k out (i out (n))=n, n=0 . . . N−1. Several other combinations of k in and k out are also possible for several alternative embodiments of the de-interleaver. In the preferred embodiments described below, i in is calculated using an index increment of 1, and the interleaving index sequence that actually performs the interleaving, i out , will simply be referred to as i. FIG. 6 shows a method used to generate the indexes for a golden relative prime interleaver embodiment based on the interleaver shown in FIG. 4 . This method starts by a first step 10 of computing the golden value g, as defined in (2) above, followed by a second step 11 of computing the real (non-integer) increment c, as defined in (4) below. Using this real increment c, a third step 12 selects an integer index increment p which is relative prime to the interleaver length N to ensure that each element is read out once and only once. The elements of the interleaving index sequence i are calculated as follows:   i ( n )= s+np , modulo N , n =0 . . . N− 1  (3) where s is an integer starting index, and n has an integer value progressively rising from 0 to N−1. The starting index s is preferably set to 0. However, other integer values of s can be selected in alternative embodiments. The integer relative prime increment p, is chosen “close” (as further defined below) to one of the non-integer values of c=N ( g m +j )/ r   (4) where g is the golden section value, m is any positive integer greater than zero, r is the index spacing (distance) between nearby elements to be maximally spread, and j is any integer modulo r. The preferred values for m are 1 and 2. Alternatively, m has one of other relatively small integer values. In a simplified implementation of this embodiment, j is set to 0 and r is set to 1. Preferably for Turbo-codes, greater values of j and r are used to obtain the best spreading for elements spaced apart by r, where r is the repetition period of the RSC encoder, rather than simply for adjacent elements. With this in mind, the preferred choices for j and r are values that result in spreading by approximate golden section spacing for adjacent elements, as well as those spaced by r. For example, j=9 and r=15 are preferred for a memory-4 Turbo-code with an RSC code repetition period of r=15. Being “close” is defined as falling within a narrow window surrounding the exact real value of c, derived as above from the golden section value g. In the simplest implementation the relative prime p is selected to have the closest value to c, for predetermined values of N, m, j, and r. In those embodiments having j=0 and r=1, the relative prime p is selected to be closest to Ng m . The result is a golden relative prime interleaver with quantization error. For large blocks, the quantization error is usually not significant for short error-burst lengths, but can grow to be significant after many increments. The quantization error problem is mitigated by performing a search for the best relative prime increment p in the vicinity of Ng m , by using a minimum difference between interleaver indexes for a maximum number of elements considered, as a measure of the spreading quality of an interleaver. Alternatively, the best relative prime increment p, in the vicinity of Ng m , is determined by a sum (or weighted sum) of minimum differences between interleaver indexes for all numbers from 2 up to a maximum number of elements considered. In this case, the best choice of p close to Ng m is that which maximizes an area under the minimum distance curve, as shown in FIGS. 9 and 10. In the golden relative prime interleaver described above, the storage vector x is not physically interleaved, but is simply read out in an interleaved order when required, without necessarily requiring a memory to store either the interleaver indexes or any interleaved results. In other words, the n'th element of the interleaved output s out (n) is simply read out of the storage vector x using the interleaving index i(n), calculated using modulo arithmetic. As interleaving is simply inherent in the reading and writing of the storage vector x, a convenient implementation of the embodiment of FIG. 4 is to use a digital signal processor (DSP) chip. Most general purpose DSP's available today offer this kind of modulo indexing to implement circular buffers. Thus, there is no need for any additional processing or memory than that required to store and read an uninterleaved vector. FIG. 10 shows the spreading properties for an interleaving method as shown in FIG. 6, having a size N=1028 (used in a Turbo-code encoder with 1024 information bits and 4 flush bits per block), j=0, r=1, m=2 and a relative prime increment of p=393. The value of c=Ng 2 is approximately 392.7. The value of p=393 is the closest relative prime. As can be seen, this golden relative prime interleaver performs well in tracking the upper bound, but does not appear to be as good as the curve shown in FIG. 9 . The area under the entire curve is 4620. This spreading measure is used to compare the performance of other embodiments discussed further below. The corresponding golden relative prime de-interleaver, also represented by FIG. 4, performs de-interleaving by writing into x (instead of reading from x) using the same interleaver indexes as described above. Alternatively, the de-interleaver writes the elements with an index increment of 1 and reads out the de-interleaved elements using an index increment of q, where pq=1, modulo N. Note that golden relative prime interleavers (and de-interleavers) do not necessarily require any memory to store the interleaver indexes, as the indexes are easily calculated as required, in either hardware or software. This is why FIG. 4 does not show any index memory. Alternatively, the indexes are stored in index memory 5 , as shown in FIG. 5 . FIG. 7 shows a method used to generate the indexes for a golden vector interleaver embodiment based on the interleaver shown in FIG. 5 . This interleaving method does not use integer relative primes and integer modulo arithmetic, but rather is based on sorting real-valued numbers derived from the golden section. A first step 20 is to compute the golden section value g. A second step 21 is to compute the real increment value c=N(g m +j)/r, where N is the interleaver length, m is any positive integer greater than zero, r is the index spacing (distance) between nearby elements to be maximally spread, and j is any integer modulo r. A third step 22 is to generate real-valued golden vector v. The elements of v are calculated as follows: v ( n )= s+nc , modulo N, n= 0 . . . N−1  (5) where s is any real starting value. The fourth step 23 is to sort golden vector v, into an increasing (or alternatively a decreasing) order, and find the index vector z that defines this sort. That is, find sort vector z such that a(n)=v(z(n)), n=0 . . . N−1, where a=sort(v). A fifth step 24 then assigns the golden vector interleaver indexes according to i(z(n))=n, n=0 . . . N−1. Vector z could also be used directly. In fact, vector z is the de-interleaver for i. The starting value s is preferably set to 0. However, other real values of s can be selected in alternative embodiments. The preferred values for m are 1 and 2. Alternatively, m has one of other relatively small integer values. In a simplified implementation of this embodiment, j is set to 0 and r is set to 1. Preferably for Turbo-codes, greater values of j and r are used to obtain the best spreading for elements spaced apart by r, where r is the repetition period of the RSC encoder, rather than simply for adjacent elements. With this in mind, the preferred choices for j and r are values that result in spreading by approximate golden section spacing for adjacent elements, as well as those spaced by r. For example, j=9 and r=15 are preferred for a memory-4 Turbo-code with an RSC code repetition period of r=15. The golden vector interleaver illustrated by FIGS. 5 and 7 does not suffer from accumulating quantization errors, as does the golden relative prime interleaver illustrated by FIGS. 4 and 6. In the golden vector interleaver case, a quantization error only occurs in the final assignment of the indexes. On the other hand, the golden vector interleaver cannot be implemented using the simple modulo-increment indexing method described above for the golden relative prime embodiment. In contrast, the golden vector interleaver indexes must be pre-computed and stored in index memory 5 as shown in FIG. 5 for each block size of interest. If the full indexes are stored, then the size of the index memory can be excessive. For example, an interleaver of length 2 16 elements would require 16×2 16 bits of index memory. By comparison, the storage vector x typically requires only 8-bit words to be stored in the element memory 2 , or half of the memory required for index memory 5 . The required size of the index memory 5 is significantly reduced when only storing index offsets. As an example, the n'th index is readily calculated as required using i(n)=floor [v(n)]+o(n), where the floor function extracts the integer part, also called the nominal index, v(n) is calculated using real modulo N arithmetic as in (5), and by definition o(n) is the required index offset stored in the index memory 5 . The number of bits that are required to store each index offset is only one or two. Thus, for the example above, the index memory is reduced to 2×2 16 bits, or about ¼ of that required for the storage vector x. This embodiment is represented by FIG. 5 . FIG. 11 shows the spreading properties for a golden vector interleaver having a size N=1028 (used in a Turbo encoder with 1024 data bits and 4 flush bits per block), j=0, r=1, and m=2. The value of real increment c=Ng 2 is approximately 392.7. As can be seen from FIG. 11, the golden vector interleaver performs very well in tracking the theoretical upper bound, and tracks it better than the golden relative prime interleaver curve shown in FIG. 10 . Note that the area under the curve has increased from 4620, for the golden relative prime interleaver, to 5250, for the golden vector interleaver, indicating that the golden vector interleaver is better at spreading out error-bursts of arbitrary length. It has been found for Turbo-codes that interleavers with some randomness tend to perform better than completely structured interleavers, especially for large block sizes on the order of 1000 or more bits. However, the spreading properties of the golden vector interleaver are still very desirable, both to maintain a good minimum distance (a steep error curve) and to ensure rapid convergence by efficiently spreading error-bursts throughout the block. These two features are encompassed in the dithered golden vector indexing method of FIG. 8 . The interleaver is again implemented using the embodiment shown in FIG. 5 . This method consists of first to fifth steps 30 to 34 similar to the first to fifth steps 20 to 24 respectively shown in FIG. 7 . The only difference between the golden vector method of FIG. 7 and the dithered golden vector method of FIG. 8 is the introduction in the third step 32 of FIG. 8 of a real perturbation (dither) vector d, having a distribution D, included in a golden vector v given by: v ( n )= s+nc+d ( n ), modulo N, n= 0 . . . N− 1,  (6) where d(n) is the n'th dither component. The distribution *D of d has prescribed parameters (e.g. width and standard deviation) with its parameters being scalable with N. In one embodiment, the added dither belongs to a uniform random distribution confined between 0 and NW D , where W D is the normalized width of the dither distribution. In an alternative embodiment, the distribution is pseudo-random and is easily calculated using a simple formula, such as that used to generate maximal-length-shift-register-sequences (m-sequences). The dithered golden vector v is sorted and the interleaver indexes are generated in a similar manner to the golden vector embodiment described above. Based on experimental findings for Turbo-codes, a crude rule of thumb for any block size is to use W D ≈0.01. The result is that for small blocks, on the order of 1000 bits or less, the effect of the dither component is small. For large blocks, on the order of 1000 bits or more, the effect of the dither component naturally increases as the block size increases. In practice, the optimum amount of dither for a specific Turbo-code is a function of the block size and the code rate obtained with puncturing. Similar to the golden vector interleaver, the dithered golden vector interleaver requires the use of index memory for storing pre-computed indexes therein, and therefore cannot be implemented using the simpler method of modulo-increment indexing. The size of index memory can be large if the full indexes are stored, as described previously for the golden vector interleaver. As for the golden vector interleaver, the required amount of index memory can be significantly reduced by only storing index offsets. As an example, the n'th index is readily calculated as required using i(n)=floor [v(n)]+o(n), where the floor function extracts the integer part, also called the nominal index, v(n) is calculated using real modulo N arithmetic as in (6), and by definition o(n) is the required index offset stored in the index memory 5 of FIG. 5 . The number of bits that are required to store each index offset is typically three or four. Thus, for the example above, the index memory is reduced to 4×2 16 bits, or about ½ of that required for the storage vector x. Alternatively, (5) is used to approximate v(n) and the effect of the dither portion is included in the index offsets, without having to compute the dither component in the interleaver. The amount of index memory required is then a function of the width of the dither distribution, but the savings in memory can still be significant. This embodiment is again represented by FIG. 5 . The dithered golden vector interleaver is found to maintain most of the desirable spreading properties of the golden vector embodiment, but is also capable of adding randomness to the interleaver to improve Turbo-code performance for large blocks, in the order of 1000 or more bits. In contrast, the golden relative prime embodiment is suitable for smaller blocks in the order of 1000 or fewer bits because it requires relatively less processing and smaller memory to implement, and provides close to the same performance as the dithered golden embodiment for those block sizes. A modification to the dithered golden vector interleaver, illustrated by FIGS. 5 and 8, is to round c, as defined in (4), either up or down to the nearest integer value. This constraint ensures that N times c, modulo N, is equal to zero, which in turn ensures that the resulting spreading properties are valid, in a modulo sense, for both the interleaver and the corresponding de-interleaver. Without this constraint, the spreading properties of the de-interleaver, measured using modulo-N arithmetic, are subject to degradation due to edge effects. This is a desirable constraint for tail-biting Turbo-codes, where the modulo-N spreading properties of the de-interleaver are just as important as the modulo-N spreading properties of the interleaver. Note that this constraint is not as severe as selecting the closest relative prime, as is the case for the golden relative prime interleaver. The dither step 32 and sorting step 33 ensure that a valid interleaver will be generated when this constraint is in effect. Although the description above concerning Turbo-codes is directed to Turbo-codes with two constituent RSC encoders and one interleaver, the same described interleaving techniques are also applicable to generalized Turbo-codes with two or more different interleavers. In the latter case, the interaction between the different interleavers becomes important. A solution that provides good relative spreading between all interleaved sequences is to use different small values of m (i.e. different powers of g) for each of the different interleavers. It is to be understood that most of the discussion above applied to the term “interleaver” applies equally to the term “de-interleaver”, and that interleaving and de-interleaving are symmetrical and inter-dependent processes. Thus, the term “interleaver” is used to refer to either an interleaver or a de-interleaver. Of course, numerous variations and adaptations may be made to the particular embodiments of the invention described above, without departing from the spirit and scope of the invention, which is defined in the claims.

Interleavers based on golden-section increments are disclosed for use with Turbo and Turbo-like error-correcting codes. The interleavers have a tendency to maximally spread the error-bursts generated by an error-burst channel or decoder, independent of the error-burst length. The code block size uniquely defines a golden section increment without having to perform a time consuming search for the best increment value. The disclosed embodiments include golden relative prime interleavers, golden vector interleavers and dithered golden vector interleavers. Also disclosed are methods to reduce the size of memory required for storing the interleaving indexes.

[0001] This application claims the benefit of U.S. Provisional Application No. 61/969321, filed Mar. 24, 2014 BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] This invention relates to fabric marking and cutting devices that are used in sewing, such as quilting to mark and cut specific angular orientation on the fabric. [0004] 2. Description of Prior Art [0005] Prior art devices of this type have provided a variety of different cutting guides; see for example U.S. Pat. Nos. 4,349,966, 5,579,670, 6,925,724 and Design Patent D374,404. [0006] U.S. Pat. No. 4,349,966 is directed to an aligning guide and measuring device having a flat with a raised flange along one edge. [0007] U.S. Pat. No. 5,579,670 discloses a method and system for making quilting pieces having a template and a cutting guide with a rail along one edge thereof. [0008] U.S. Pat. No. 6,925,724 illustrates a square or rectangular quilting ruler with sets of equally spaced rulings running parallel thereto and at right angles so as to be visible when in associated use. [0009] U.S. Pat. No. 7,568,295 claims a quilting tool having a transparent parallelogram plate and guidelines associated thereon. [0010] Finally, in Design Patent D374,404, a quilting ruler is shown having a rectangular surface with a flange inwardly of one edge. SUMMARY OF THE INVENTION [0011] A fabric alignment, marking and cutting guide having a self-healing fabric placement surface on which the alignment guide with a top and side raised material engagement edge surfaces are positioned. A hinged transparent triangle guide plate extends from one raised surface for select placement over fabric positioned and aligned on the cutting surface for accurate repetitive diagonal marking and cuts there along. DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a perspective view of the fabric alignment marking and cutting guide of the invention. [0013] FIG. 2 is a top plan view thereof shown in use by marking for cutting. [0014] FIG. 3 is a top plan view illustrating alternate material placement on the cutting surface with guide edge engagement for cutting. [0015] FIG. 4 is a top plan view of an alternate use configuration with an independent straight edge. DETAILED DESCRIPTION OF THE INVENTION [0016] Referring to FIG. 1 of the drawings, a fabric alignment marking and cutting guide 10 of the invention can be seen having a support base 11 with spaced oppositely disposed parallel top and bottom edges 12 and 13 and corresponding spaced parallel perimeter side edges 14 and 15 defining a square base configuration. Preferably the base material is of a self-healing configuration so that it can be effectively cut upon without permanent markings affecting future cutting as will be well known and understood by those skilled in the art. [0017] A pair of upstanding perimeter flat guide angles 16 and 17 are positioned at right angles to one another along and extend inwardly from the respective top edge 12 and the side edge 14 of the base 11 . The guide angles 16 and 17 have effacing ends 16 A and 17 A which are in spaced angular orientation to one another forming a cutting gap at 18 therebetween that aligns with the primary diagonal line D illustrated by a line indicia positioned on the base 11 and a secondary parallel line D′ for aligning to mark ¼ inch from the edge of fabrics as will be described in greater detail hereinafter. [0018] A right angle triangular transparent guide panel 19 is hinged along one side to the perimeter guide angle 16 by a selective hinge configuration 20 . A lifting tab 21 is formed integrally with and extends from a free side edge surface 22 adjacent the panel's defined angular edge cutting surface 23 . The hinged configuration 20 may be of any continuous (piano type) or multiple spaced hinged elements so as to assure edge orientation when selectively operated from a first flat base engagement position to an upstanding position as seen in solid and broken lines in FIG. 1 of the drawings. [0019] It will be seen that the cutting guide edge surface 23 of the hinged triangular guide transparent guide panel 19 defines a “true” diagonal across a surface S of the support base 11 and is correspondingly in alignment between the hereinbefore described end gap 18 between the respective guide angles 16 and 17 which will allow for a continuous cutting action therealong as will be described in detail hereinafter. [0020] In use, the fabric alignment, marking and cutting guide 10 , as seen in FIGS. 2 and 3 of the drawings (in this example) a fabric square 24 to be cut is positioned on the support base 11 's surface S which is divided into equal portions by a cross gridline pattern 25 . The transparent guide panel 19 is raised and the fabric square 24 is placed on the grid line supporting base 11 surface S in abutting relationship to the respective perimeter guide angles 16 and 17 . The guide panel 19 is then lowered onto the fabric square 24 holding it firmly in place. It will be seen that this provides a true and accurate diagonal guide there across for marking M or cutting along the guide edge surface 23 of the guide panel 19 which in this example for cutting an illustrative rotary cutter representation 26 is shown graphically in FIG. 3 of the drawings and is well known in the art can pass along against the guide edge surface 23 cutting the fabric panel 24 diagonally and proceed through the angle gap 18 in a single continuous action or conversely begin at the angle gap 18 and pass along the guide edge surface 23 cutting the fabric as noted. [0021] Alternate fabric square placement is possible and can be seen as illustrated in FIG. 3 of the drawings wherein a fabric square 26 is aligned on the base 11 surface S by use of the gridline pattern 25 and a diagonal marking and a cut can be made, again by using the triangular guide panel 19 positioned thereover, as described. [0022] It will be evident from the above description that the divided grid line pattern 25 on the base 11 can also be used independently of the guide panel 19 as seen in FIG. 4 of the drawings as follows. A fabric square 27 can therefore be positioned on the base surface S by the alignment with the gridline pattern 25 and independent straight edge 28 may be used to overlie and act as a marking guide via a marker M, in broken lines, and then a cutting edge guide for a rotary cutter representation 29 as illustrated. [0023] The support base 11 in this example, as noted, is preferably made of a self-healing cutting mat surface of a ⅛ inch thickness and divided by the right angular cross gridline pattern 25 in equal incremental increments, such as one-inch in this illustration or other dimensional aspects chosen for alternate applications as would be evident to those skilled in the art. Additionally, a secondary guide line D′ can be seen in spaced relation to the primary diagonal line D which would allow for aligning to mark ¼ inch from the edge of fabrics. [0024] It will be seen that incremental indicia measurements are marked along each of the guide angles 16 and 17 , in this example at one-inch and ⅛ inch intervals and may be of different colors for easy identification. The transparent movable guide edge panel 19 is preferably made of synthetic resin material with a non-slip bottom surface BS for engagement against the fabric to assure stability thereto while marking or cutting. [0025] It will thus be seen that a new and novel fabric alignment marking and cutting guide of the invention has been illustrated and described and will provide ability to selectively mark diagonal lines on square fabrics fast, easy and accurately. It is evident that the guide is a time saving device when marking the squares and that the straight edge corner liners will assure that the diagonal mark is accurate and the right triangle remains stationary when marking to assure the diagonal mark is also accurate. The cutting base 11 can be used as a cutting surface for rotary cutters, as described, and wherein the right angle panel 19 can be used to guide the rotary blade when cutting diagonal lines as hereinbefore described. [0026] It will thus be evident that various changes and modifications may be made thereto without departing from the spirit of the invention. Therefore I claim:

A fabric alignment, marking and/or cutting guide that allows for accurate marking, and/or cutting of fabric along the diagonal using a multiple axis fixed edge alignment and a movable triangular angle. The alignment guide has a square cutting board with right angularly positioned upstanding angular edge surfaces for material engagement. A transparent hinged triangular cutting guide plate extends from one alignment edge surface defining a true diagonal line guide edge across a material square to be marked and cut positioned on the cutting board under the triangle guide plate.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the priority of Korean Patent Application Nos. 10-2009-0127546 filed on Dec. 18, 2009, and 10-2010-0035945 filed on Apr. 19, 2010, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wideband receivers, and more particularly, to a wideband receiver that has a smaller area and consumes less power and can prevent harmonic mixing occurring due to an increase in the number of communications systems using wideband. 2. Description of the Related Art An application using wideband, such as a digital TV, frequently undergoes harmonic mixing as shown in FIGS. 1A , 1 B and 1 C. As shown in FIG. 1A , as for wideband applications, undesirable signals are present at frequencies three or five times the magnitude of a carrier frequency of an input signal (an RF signal). By a frequency three or five times the magnitude of a frequency of a local oscillator (LO) signal, shown in FIG. 1B , these signals are moved down to baseband frequencies together with a desired signal when the frequency of the desired signal is down-converted to baseband by a down-conversion mixer, which is illustrated in FIG. 1C . In order to solve the above-described problem of harmonic mixing, in the related art, a dual conversion receiver has been used. As shown in FIG. 2 , a dual conversion receiver amplifies an input signal RFin by a wideband low-noise amplifier (hereinafter, referred to as an “LNA”) 211 and up-converts the amplified input signal to high intermediate frequency (IF) by an up-conversion mixer 212 . The input signal being up-converted is filtered through a narrowband surface acoustic wave (SAW) filter 213 , is then moved to low IF by down-conversion mixers 221 and 222 , and is finally output via IF variable gain amplifiers (hereinafter, referred to as “VGAs”) 223 and 224 and low pass filters (hereinafter, referred to as “LPFs”) 225 and 226 . However, the dual conversion receiver having the above-described configuration and performing the above-described operation has various problems as follows. First, the use of additional external components, such as the narrowband SAW filter 213 , causes an increase in manufacturing costs. Besides, unlike existing receivers, the dual conversion receiver requires two frequency synthesizers 214 and 228 and two or more mixers, that is, the up-conversion mixer 212 and the down-conversion mixers 221 , and 222 , thereby increasing the size of the receiver and the amount of power being consumed. In order to solve these problems of the dual conversion receiver, in the related art, another receiver that includes a harmonic suppression mixer having a plurality of mixers connected in parallel with each other was additionally proposed. However, since the harmonic suppression mixer has a larger area and consumes more power than existing mixers, the area and power consumption of the receiver having the harmonic suppression mixer therein are therefore increased. Besides, the harmonic suppression mixer requires a plurality of multi-phase local oscillator signals, and accurate phase differences need to exist between the plurality of local oscillator signals. For this reason, additional circuits need to be added in order to control the phase differences between the plurality of local oscillator signals, which result in the receiver having a higher area and high power consumption. SUMMARY OF THE INVENTION An aspect of the present invention provides a wideband receiver having new architecture that has a smaller area and consumes less power and can prevent harmonic mixing occurring due to an increase in the number of communications systems using wideband. According to an aspect of the present invention, there is provided a wideband receiver including: an front-end unit receiving and performing low-pass filtering on a wideband input signal in a continuous-time domain; and a down-conversion unit sampling and holding an output signal of the front-end unit according to a local oscillator signal and performing low-pass filtering on the output signal in a discrete tie domain. The front-end unit may include: a wideband low-noise amplifier receiving and amplifying the wideband input signal; and at least one tunable low pass filter changing cutoff frequency according to a frequency of the wideband input signal and performing low-pass filtering on the wideband input signal. The at least one tunable low pass filter may include: first and second resistors connected in series between an input terminal and an output terminal; a first capacitor connected between a ground and a contact point between the output terminal and the second resistor; a second capacitor and an output resistor connected between the ground and a contact point between the first resistor and the second resistor; and a buffer connected between the output terminal and a contact point between the second capacitor and the output resistor. The buffer may be configured as an operational amplifier having a gain of 1. The at least one tunable low pass filter may change the cutoff frequency by changing a device value of at least one of the first and second resistors and the first and second capacitors. The at least tunable low pass filter further may include: a first transistor of a first conductivity type having a gate connected to the input terminal and a source to which a driving voltage is applied; a first transistor of a second conductivity type having a gate and a drain connected in common to a drain of the first transistor of the first conductivity type; and a second transistor of a first conductivity having a gate and a drain connected in common to the output terminal and a source connected to the driving voltage terminal. The buffer may be configured as a second transistor of a second conductivity type having a gate connected to the first capacitor, a drain connected to the drain of the second transistor of the first conductivity type, and a source connected to the second capacitor. The down-conversion unit may include: a clock generator generating a clock; a phase shifter shifting a clock with a phase difference of 90° to thereby generate the local oscillator signal required to restore an I/Q signal; two sample and hold circuits sampling and holding the output signal of the front-end unit according to the local oscillator signal in the discrete-time domain, down-converting the output signal of the front-end unit to baseband, and converting the output signal into a signal in the discrete-time domain; and two discrete-time low pass filters performing low-pass filtering on respective outputs of the two sample and hold circuits in the discrete-time domain. Each of the two sample and hold circuits may include: a first transistor having a drain connected to a first input terminal and a gate to which a local oscillator signal is input; a second transistor having a drain connected to a second input terminal and a gate to which the local oscillator signal is input; a third transistor having a drain connected to a source of the first transistor, a gate to which an inverted local oscillator signal is input, and a source connected to an output terminal; a fourth transistor having a drain connected to a source of the second transistor, a gate to which the inverted local oscillator signal is input, and a source connected to a bias voltage; a fifth transistor having a drain connected to the output terminal and a gate to which the local oscillation signal is input; a first capacitor connected between the source of the first transistor and the source of the second transistor; a second capacitor connected between the output terminal and a source of the fifth transistor; and a third capacitor connected between the second capacitor and a ground. The two sample and hold circuits may receive respective output signals of the front-end unit in the form of a differential signal pair through the first and second input terminals. The clock generator may vary a frequency of the clock. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIGS. 1A , 1 B, and 1 C are views illustrating harmonic mixing; FIG. 2 is a view illustrating a dual conversion receiver according to the related art; FIG. 3 is a view illustrating a wideband receiver according to an exemplary embodiment of the present invention; FIG. 4 is a view illustrating a tunable LPF according to an exemplary embodiment of the present invention; FIG. 5 is a view illustrating a tunable LPF according to another exemplary embodiment of the present invention; FIG. 6 is a view illustrating a tunable LPF according to another exemplary embodiment of the present invention; FIGS. 7A and 7B are graphs illustrating the filter characteristics of the tunable LPF of FIG. 5 ; FIGS. 8A and 8B are graphs illustrating the filter characteristics of the tunable LPF of FIG. 6 ; and FIG. 9 is a view illustrating a sample and hold circuit according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As the present invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in drawings and described in detail in the written description. However, this is not intended to limit the present invention to particular modes of practice, and it is to be appreciated that all changes, equivalents, and substitutes that do not depart from the spirit and technical scope of the present invention are encompassed in the present invention. While such terms as “first” and “second,” etc., may be used to describe various components, such components must not be limited to the above terms. The above terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component without departing from the scope of the rights of the present invention, and likewise, a second component may be referred to as a first component. When a component is mentioned to be “connected” to or “accessing” another component, this may mean that it is directly connected to or accessing the other component, but it is to be understood that another component may exist in-between. On the other hand, when a component is mentioned as being “directly connected” to or “directly accessing” another component, it is to be understood that there are no other components in-between. The terms used in the present application are merely used to describe particular embodiments, and are not intended to limit the present invention. An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context. In the present application, it is to be understood that the terms such as “including” or “having,” etc., are intended to indicate the existence of the features, numbers, operations, actions, components, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, operations, actions, components, parts, or combinations thereof may exist or may be added. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meanings as those generally understood by those with ordinary knowledge in the field of art to which the present invention belongs. Such terms as those defined in a generally used dictionary are to be interpreted to have meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present application. Embodiments of the present invention will be described below in detail with reference to the accompanying drawings, where those components are rendered the same reference number that are the same or correspond to, regardless of the figure number, and redundant explanations are omitted. FIG. 3 is a view illustrating a wideband receiver according to an exemplary embodiment of the invention. Referring to FIG. 3 , a wideband receiver according to this embodiment includes an front-end unit 310 and a down-conversion unit 320 . The front-end unit 310 receives and performs low-pass filtering on a wideband input signal in the continuous-time domain. The down-conversion unit 320 samples and holds an output signal from the front-end unit 310 according to a local oscillator signal and performs low-pass filtering on the output signal in the discrete-time domain. The front-end unit 310 includes a wideband LNA 311 and a tunable low pass filter (hereinafter, referred to as a “tunable LPF”) 312 . The wideband LNA 311 receives and amplifies the wideband input signal RFin. The tunable LPF 312 can change cutoff frequency and performs low-pass filtering on the input signal according to the cutoff frequency in the continuous-time domain. Here, the tunable LPF 312 may be a high pass filter in order to remove signals present at frequencies higher than a desired frequency to thereby prevent harmonic mixing. Furthermore, since the amplitude of an undesirable signal cannot be reduced to a desired level or less unless the cutoff frequency (or 3 dB frequency) is changed according to the frequency of the input signal RFin, the cutoff frequency can be changed according to the frequency of the input signal RFin. The down-conversion unit 320 includes a clock generator 321 , a phase shifter 322 , two sample and hold circuits (hereinafter, referred to as “SAH circuits”) 323 and 324 , and discrete-time low pass filters (hereinafter, referred to as “DT LPFs”) 325 and 326 . The clock generator 321 generates a clock. The phase shifter 322 shifts the clock with a phase difference of 90° to thereby generate a local oscillator signal LO required to restore an I/Q signal. The SAH circuits 323 and 324 each sample and hold a signal, being output from the front-end unit 310 , according to the local oscillator signal LO in the discrete-time domain, down-convert the signal to baseband, and then convert the signal to a signal in the discrete-time domain. The DT LPFs 325 and 326 perform low-pass filtering on respective outputs from the SAH circuits 323 and 324 in the discrete-time domain. Here, according to the known art, the DT LPFs 325 and 326 may be IIR (infinite impulse response) filters or FIR (finite impulse response) filters. A detailed description thereof will be omitted. That is, as the down-conversion unit 320 uses the SAH circuits 323 and 324 and the DT LPFs 325 and 326 that are operable in the discrete-time domain, the down-conversion unit 320 can be operated in the discrete-time domain. Here, the operating characteristics of the down-conversion unit 320 can be varied by changing the frequency of the clock, being generated by the clock generator 321 . In particular, the filtering characteristics of the DT LPFs 325 and 326 can be easily changed according to the frequency of the clock, so that the wideband receiver according to the exemplary embodiment of the invention can be used in various manners in another applications as well as digital TVs. Furthermore, the DT LPFs 325 and 326 also serve as decimation filters used to reduce respective sampling frequencies of the SAH circuits 323 and 324 . In comparison with LPFs operating in the continuous-time domain, the DT LPFs 325 and 326 are less sensitive to process, voltage and temperature variations, thereby increasing the reliability of the operation of the wideband receiver. FIG. 4 is a view illustrating a tunable LPF according to an exemplary embodiment of the invention. As shown in FIG. 4 , a tunable LPF 312 - 1 has a structure of a Sallen-Key filter. More specifically, the tunable LPF 312 - 1 includes first and second resistors R 1 and R 2 connected in series between an input terminal IN and an output terminal OUT, a first capacitor C 1 connected between a ground and a contact point between the output terminal OUT and the second resistor R 2 , a second capacitor C 2 and an output resistor Rout connected in series between the ground and a contact point between the first resistor R 1 and the second resistor R 2 , and a buffer B connected between the output terminal OUT and a contact point between the second capacitor C 2 and the output resistor Rout. Here, the buffer B may be configured as an operational amplifier having a gain of “1”. The tunable LPF having the above-described configuration determines the cutoff frequency fcutoff according to Equation 1. f cutoff = 1 2 ⁢ π ⁢ C ⁢ ⁢ 1 ⁢ C ⁢ ⁢ 2 ⁢ R ⁢ ⁢ 1 ⁢ R ⁢ ⁢ 2 Equation ⁢ ⁢ 1 Referring to Equation 1, it can be seen that the cutoff frequency fcutoff of the tunable LPF is determined by device values of the first and second resistors R 1 and R 2 and the first and second capacitors C 1 and C 2 . In the present invention, therefore, at least one of the first and second resistors R 1 and R 2 and the first and second capacitors C 1 and C 2 is realized as an array or variable device, and a device value thereof is changed according to the frequency of the input signal RFin, so that the cutoff frequency fcutoff is finally changed. Generally, when both the input and output of the LPF are voltages, linearity in a low frequency band may be reduced. In particular, since the V-I characteristic of the transistor is not linear, if V-I conversion continues to be performed, the linearity in the low frequency band can be further reduced. Thus, in the present invention, as shown in FIG. 5 , components are added in order to convert voltages at the input terminal IN and the output terminal OUT of the tunable LPF, shown in FIG. 4 , into currents, so that the input of the LPF is changed into a current. FIG. 5 is a view illustrating a tunable LPF according to another exemplary embodiment of the invention. Referring to FIG. 5 , a tunable LPF 312 - 2 includes the first through third output resistors R 1 , R 2 , and Rout, the first and second capacitors C 1 and C 2 , and the buffer B as shown in FIG. 4 . The tunable LPF 312 - 2 further includes a first PMOS transistor PM 1 , a first NMOS transistor NM 1 , an output resistor Rout, and a second PMOS transistor PM 2 . The first PMOS transistor PM 1 has a gate connected to an input terminal IN and a source to which a driving voltage Vdd is applied. The first NMOS transistor NM 1 has a gate and a drain connected in common to a drain of the first PMOS transistor PM 1 . The output resistor Rout is connected to a source of the first NMOS transistor NM 1 . The second PMOS transistor PM 2 has a gate and a drain connected in common to an output terminal OUT and a source connected to a driving voltage Vdd terminal. That is, as the first PMOS transistor PM 1 and the first NMOS transistor NM 1 are added to the input terminal IN of the tunable LPF 312 - 2 , shown in FIG. 5 , and the second PMOS transistor PM 2 is added to the output terminal OUT thereof, the tunable LPF 312 - 2 converts an input voltage and an output voltage into an input current and an output current, respectively, by using the added components. Furthermore, as shown in FIG. 5 , the buffer B, shown in FIG. 4 , may be realized as a second NMOS transistor NM 2 having a gate connected to the first capacitor C 1 , a drain connected to the drain of the second PMOS transistor PM 2 , and a source connected to the second capacitor C 2 . Basically, a transistor can be driven using power smaller than that of an operational amplifier, in the case that a buffer of the operational amplifier is replaced with a transistor, the amount of power being consumed by the tunable LPF can be reduced. Furthermore, when a rejection ratio of the tunable LPF having the configuration as shown in FIGS. 4 and 5 is not high enough, a plurality of tunable LPFs are connected in series with each other as shown in FIG. 6 , so that a rejection ratio with respect to an undesirable signal can be improved. FIG. 6 is a view illustrating a tunable LPF according to another exemplary embodiment of the invention. Referring to FIG. 6 , a tunable LPF 312 - 3 has a plurality of tunable LPFs 312 - 2 as shown in FIG. 4 or FIG. 5 , connected in series with each other. When the tunable LPFs, shown in FIG. 6 , are configured using the tunable LPFs 312 - 2 as shown in FIG. 5 , a second PMOS transistor PM 2 of the tunable LPF 312 - 2 , provided at a front stage, and a first PMOS transistor PM 1 of the tunable LPF 312 - 2 , provided at a rear stage, are connected in a current mirror configuration. As a result, an output current of the tunable LPF 312 - 2 , provided at the front stage, is thereby applied as an input current of the tunable LPF 312 - 2 , provided at the rear stage. FIGS. 7A and 7B are views illustrating the filter characteristics of the tunable LPF as shown in FIG. 5 . FIGS. 8A and 8B are views illustrating the filter characteristics of the tunable LPF as shown in FIG. 6 . As shown in FIGS. 7A and 7B and 8 A and 8 B, a tunable LPF according to an exemplary embodiment of the invention can optionally control the cutoff frequency by changing device values of resistors and capacitors. That is, as shown in FIGS. 7A and 7B and 8 A, a cutoff frequency may be set to 80 MHz. Alternatively, as shown in FIGS. 7A and 7B and 8 B, a cutoff frequency may be set to 1 GHz. Through a comparison between the drawings of FIGS. 7A and 7B and FIGS. 8A and 8B , it can be seen that the tunable LPFs, shown in FIG. 6 , have a higher rejection ratio than the tunable LPF, shown in FIG. 5 . That is, by connecting the tunable LPFs, as shown in FIG. 5 , in series with each other, a rejection ratio with respect to an undesirable signal can be increased. FIG. 9 is a view illustrating an SAH circuit according to an exemplary embodiment of the invention. As shown in FIG. 9 , each of the SAH circuits 323 and 324 includes a first transistor M 1 , a second transistor M 2 , a third transistor M 3 , a fourth transistor M 4 , a fifth capacitor M 5 , a first capacitor C 1 , a second capacitor C 2 , and a third capacitor C 3 . The first transistor M 1 has a drain connected to a first input terminal INP and a gate to which a local oscillator signal LO+ is input. The second transistor M 2 has a drain connected to a second input terminal INN and a gate to which a local oscillator signal LO+ is input. The third transistor M 3 has a drain connected to a source of the first transistor M 1 , a gate to which an inverted local oscillator signal LO− is input, and a source connected to an output terminal OUT. The fourth transistor M 4 has a drain connected to a source of the second transistor M 2 , a gate to which the inverted local oscillator signal LO− is input, and a source connected to a bias voltage VBIAS terminal. The fifth transistor M 5 has a drain connected to the output terminal OUT and a gate to which the local oscillator signal LO+ is input. The first capacitor C 1 is connected between the source of the first transistor M 1 and the source of the second transistor M 2 . The second capacitor C 2 is connected between the output terminal OUT and a source of the fifth capacitor M 5 . The third capacitor C 3 is connected between the second capacitor C 2 and a ground. Here, the SAH circuit has a differential structure receiving an output of the tunable LPF 312 and a local oscillator signal from the phase shifter 322 in the form of a differential signal pair. Hereinafter, the operation of the SAH circuit will be described. First, when a local oscillator signal pair consisting of a local oscillator signal LO+ and an inverted local oscillator signal LO− and having a first value is applied (for example, a local oscillator signal LO+ has a high level and an inverted local oscillator signal LO− is a low level), the first, second, and fifth capacitors M 1 , M 2 , and M 5 are turned on, and the third and fourth transistors M 3 and M 4 are turned off. Both ends of the first capacitor C 1 are then connected to the first and second input terminals INP and INN, respectively, a signal value of the input signal pair is stored in the first capacitor C 1 . Subsequently, when a local oscillator signal pair consisting of a local oscillator signal LO+ and an inverted local oscillator signal LO− and having a second value is applied (for example, the local oscillator signal LO has a low level, and the inverted local oscillator signal LO− has a high level), the first, second, and fifth capacitors M 1 , M 2 , and M 5 are turned off, and the third and fourth transistors M 3 and M 4 are turned on. The signal value of the input signal pair, stored in the first capacitor C 1 , is finally output to the third transistor M 3 and the second capacitor C 2 . That is, the SAH circuit, as shown in FIGS. 8A and 8B , samples the signal value of the input signal pair in a half period of the local oscillator signal pair consisting of the local oscillator signal LO+ and the inverted local oscillator signal LO−, and outputs the sampled signal value to the output terminal OUT. As set forth above, according to exemplary embodiments of the invention, a wideband receiver receives and performs low-pass filtering on a wideband input signal in the continuous-time domain, down-converts the wideband input signal, and performs low-pass filtering on the wideband input signal in the discrete-time domain. Therefore, a large number of PLLs and mixers are not required, so that the wideband receiver has a small area and consumes less power and can prevent harmonic mixing. Furthermore, since a down-conversion unit is operated in the discrete-time domain, the filtering characteristics of the down-conversion unit can be varied by changing the frequency of a clock required to operate the down-conversion unit. While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.

Provided is a wideband receiver that has a smaller area and consumes less power and can prevent harmonic mixing occurring due to an increase in the number of communications systems using wideband. A wideband receiver according to an aspect of the invention may include: an front-end unit receiving and performing low-pass filtering on a wideband input signal in a continuous-time domain; and a down-conversion unit sampling and holding an output signal of the front-end unit according to a local oscillator signal and performing low-pass filtering on the output signal in a discrete tie domain.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. patent application Ser. No. 13/624,020 filed Sep. 21, 2012, the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND [0002] 1. Technical Field [0003] The present invention relates to electronic authentication. [0004] 2. Discussion of the Related Art [0005] Authentication using mobile devices is a growing commodity. However, using a set of challenges like pre-defined passwords or pin numbers introduces a risk of compromising the integrity of the authentication process. From badge readers, to financial transactions based on near field communication, the risk of presenting a static/pre-defined set of credentials is part of the problem, not part of the solution. For example, if a badge has to present the same code to a reader, a mobile device has to present the same set of credentials (e.g., password, PIN number, etc.) to complete a transaction, or a credit card has the same information stored in a magnetic field, hackers may find ways to break into these static vaults and acquire credentials. BRIEF SUMMARY [0006] The present invention discloses a system and method for generating a master key and subsequent images which contain a combination of meaningful and non-meaningful information. The master key image contains a list of meaningful polygons (or other descriptors) which allow the reader of the these transmitted images to assemble a virtual aggregate key. The resultant key is therefore never transmitted but is rather assembled dynamically from the sequence of images. [0007] In an exemplary embodiment of the present invention, the method includes: receiving, at a first device, a challenge provided from a second device, wherein the challenge includes an encoding algorithm and a request for credentials from the first device; and outputting, from the first device to the second device, a response to the challenge, wherein the response includes at least one image, the at least one image including an article of evidence arranged according to the encoding algorithm. [0008] The encoding algorithm identifies where the article of evidence is to be positioned in the at least one image. [0009] The article of evidence is included within a polygon in the at least one image. [0010] The at least one image includes a bar code. [0011] The first device includes a mobile device. [0012] The second device includes a server. [0013] The method further comprises: authenticating the first device in response to the challenge response; and permitting the first device to access a desired resource in response to the authentication of the first device, wherein the authenticating and permitting are performed using the second device. [0014] The first device or the second device is a program or a virtual device. [0015] The at least one image includes a quick response code. [0016] In an exemplary embodiment of the present invention, the method includes: receiving, at a first device, a challenge from a second device, wherein the challenge includes a request for credentials from the first device; and outputting, from the first device to the second device, a response to the challenge, wherein the response includes an encoding algorithm and at least one image that includes an article of evidence arranged according to the encoding algorithm. [0017] The encoding algorithm is included in an image. [0018] The method further comprises extracting, at the second device, the article of evidence from the at least one image according to the encoding algorithm. [0019] In an exemplary embodiment of the present invention, the method includes: receiving, at a first device, a challenge request from a second device, wherein the challenge request includes a request for credentials from the first device and an identification of areas where the credentials are to be included in images; generating, with the first device, a plurality of images, wherein at least one image includes at least one article of evidence indicative of at least one of the credentials, and the at least one article of evidence is arranged in the image as indicated by the area corresponding thereto; providing, from the first device, the plurality of images as a composite image to the second device; providing the composite image to a third device from the second device; and validating, at the third device, the first device using the composite image. [0020] Prior to the challenge request being sent to the first device from the second device, the challenge request is generated in the third device and provided to the second device based on an initial communication between the first and second devices. [0021] The first device includes a mobile device, the second device includes a validator and the third device includes a server. [0022] In an exemplary embodiment of the present invention, the method includes receiving, at a first device, a challenge request from a second device, wherein the challenge request includes a request for credentials from the first device; generating, with the first device, a plurality of images, wherein each image includes at least one article of evidence indicative of at least one of the credentials, and the at least one article of evidence is arranged in the image according to an encoding algorithm; providing, the plurality of images as a composite image to a third device; and providing the composite image to the second device from the third device. [0023] The first device includes a mobile device, the second device includes a server and the third device includes a validator. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0024] FIG. 1 illustrates a challenge request and a challenge response according to an exemplary embodiment of the present invention; [0025] FIG. 2 illustrates images included in a challenge response according to an exemplary embodiment of the present invention; [0026] FIG. 3 illustrates a challenge request and a challenge response according to an exemplary embodiment of the present invention; [0027] FIG. 4 illustrates images included in a challenge response according to an exemplary embodiment of the present invention; [0028] FIG. 5 illustrates an authentication flow between a mobile device, validator and server according to an exemplary embodiment of the present invention; [0029] FIG. 6 illustrates an authentication flow between a mobile device, validator and server according to an exemplary embodiment of the present invention; and [0030] FIG. 7 illustrates an apparatus for implementing an exemplary embodiment of the present invention. DETAILED DESCRIPTION [0031] The invention disclosed herein introduces two main concepts that work in concert to provide the needed level of security to ensure a random and unique authentication process. [0032] First, the invention elevates the security challenge to be dynamic and not stored on a mobile device. For example, the server generates a new challenge and provides it to the mobile device. An application/logic layer in the mobile device will respond and stream the challenge response. Then, resource access is granted by the server, e.g., meaning authentication completion. As a result, predicting the type of challenge and the outcome of that challenge is virtually impossible. [0033] Second, the invention minimizes identity theft as an identity is represented as a series of articles that are dependant on one another. Getting a hold of any single article is useless. Getting a hold of all of them without knowing how to assemble them is useless as well. [0034] In accordance with exemplary embodiments of the present invention, a mobile device may be a smart phone, a tablet, a laptop, a smart card, for example, a validator may be a badge reader, a credit card reader, a proxy server, for example, and the server may be cloud based, for example. The validator may also be a program in the cloud. Further, a non-portable compute device may be used in place of the mobile device. Further, the mobile device, validator and server may be a program or a virtual device. [0035] In accordance with exemplary embodiments of the present invention, a requested resource may be access to a protected room, access to a digital file, access to email, or access to any other digital or physical assets, for example. [0036] A method in accordance with an exemplary embodiment of the present invention will now be discussed. More particularly, a method for authentication between a mobile device and a server is disclosed hereafter with reference to FIGS. 1 and 2 . [0037] As shown in FIG. 1 , a mobile device and a server are in communication with each other. The initiation of this communication may occur as the result of the mobile device requesting a resource from the server via a middleman. The initiation process will be discussed later. In response to the resource request, the server provides a challenge request to the mobile device ( 1 ). The challenge request contains credentials that the server wants from the mobile device as well as an encoding algorithm. The encoding algorithm indicates how the credentials are to be encoded by the mobile device. The encoding algorithm may be described within a descriptor file included in a descriptor/manifest image, for example. [0038] More specifically, the challenge request may ask the mobile device to provide the following as credentials: device model, GPS chip type, processor chip type, etc. As it pertains to encoding, the challenge request may ask the mobile device to provide each of these credentials in a separate image and to group these images as a composite image. Further, with regard to encoding, the challenge request may ask the mobile device to put the credentials in specific areas of the images. For example, the challenge request may require the device model to be put in polygon X in position X of image X, the GPS chip type to be put in polygon Y in position Y of image Y and the processor chip type to be put in polygon Z in position Z of image Z. [0039] Although the above challenge request asks for credentials pertaining to hardware aspects of the mobile device, the credentials are not limited thereto. For example, the requested credentials may include the name of a user, the operating system of the device, the user's password, device attributes, compute node attributes (e.g., MAC address). More than one credential may be put in a single image. The composite image may be animated. [0040] The mobile device may provide a response to the challenge request ( 2 ). The challenge response may include the encoded credentials. An example of the challenge response is shown in FIG. 2 . [0041] For example, image A may include the device model in polygon 1 in the location of image A specified by the server. Image B may include the GPS chip type in polygon 2 in the location of image B specified by the server. Image C may include the processor chip type in polygon 3 in the location of image C specified by the server. Image D may include the device's build number in polygon 4 in the location of image D specified by the server. The combination of all these images is shown as the composite image in FIG. 2 . [0042] Although quick response (QR) codes are shown as the images in FIG. 2 , other types of barcodes may be used as the images. Further, non-barcode images may be used as well. For example, an image of the mobile device's user may be chosen by the server as the image in which to embed the requested credentials. In this case, the server may tell the mobile device to insert the device type into the right eye of the user, the GPS chip type into the left eye of the user and a password into the mouth of the user. [0043] As can be seen, with the type of challenge request disclosed above, the challenge response encoding permutations are almost infinite. [0044] Upon receipt of the challenge response from the mobile device, the server may authenticate credentials therein and provide the mobile device with the requested resource. Authentication is possible, since the server knows the encoding of the data in the composite image. On the other hand, the authentication may be performed by the middleman. This is will be discussed later. [0045] A method in accordance with an exemplary embodiment of the present invention will now be discussed. More particularly, a method for authentication between a mobile device and a server is disclosed hereafter with reference to FIGS. 3 and 4 . [0046] As shown in FIG. 3 , the server provides a challenge request to the mobile device ( 1 ). However, unlike that shown in FIG. 1 , the challenge request only includes the credentials that the server wants from the mobile device. The mobile device may provide a response to the challenge request ( 2 ). Unlike the challenge response shown in FIG. 2 , the challenge response may include an encoding algorithm and the encoded credentials. The encoding algorithm may be selected by the mobile device. An example of the challenge response is shown in FIG. 4 . [0047] For example, descriptor/manifest image contains the encoding algorithm details. In other words, it identifies the credentials 1-4 and where the credentials are to be found in each of images A-D. In more detail, the encoding algorithm is described within a descriptor file within the descriptor/manifest image. An example descriptor file is shown below. [0000] <descriptor file> <challenge> <article>device model </article> <encoding>Image A, Polygon 1</encoding> </challenge> </ descriptor file> [0048] The descriptor file can be obfuscated using any of a plurality of methods that the server is known to understand. For example, in addition to being included in the descriptor/manifest image, it may encrypted or password protected. Further, the descriptor file may not be a file at all; rather, the information included therein may be dependent on the protocol used for communication. [0049] As mentioned above, the user that is requiring access to some resource is faced with a middleman between the user's device and the server. This interaction will now be discussed with references to FIGS. 5 and 6 . [0050] As shown in FIG. 5 , to initiate a request for a resource access, which in turn initiates an authentication process, a mobile device can be bumped or be in close proximity to a validator (e.g., badge reader), when both devices employ near field communication for example. Any approach used to establish radio or non-radio communication between two or more devices may be used in accordance with this invention. The validator may now act as the middleman between the server and the mobile device. In this scenario, the mobile device knows nothing about the server. [0051] The validator obtains a challenge from the server and provides that challenge to the mobile device. The challenge may be generated by a challenge engine of the server. In accordance with an exemplary embodiment of the present invention, the validator may ask the mobile device to stream a series of processed images using a specified algorithm. The number of images to be streamed back and the algorithm applied on each image may be variable each time the validator is engaged. [0052] As shown in FIG. 5 , the mobile device has the logic needed (e.g., challenge response generator) to translate the challenge communicated and prepare/present a challenge response. The mobile device also has the logic needed (e.g., descriptor file) to encode its data if no encoding algorithm is provided from the server. The challenge response generator of the mobile device generates a plurality of individual images II 0 . . . II n to create a final image II final . Here, the II refer to intelligent images such as QR codes. The final image, which may be the generated series of images or a composite (e.g., aggregated images, such as animated images or video) is streamed back to the validator. The validator can perform extraction of data from sent images then send the data to the server, or it can send the raw challenge response to the server for analysis by its validation engine. [0053] In the exemplary embodiment shown and described with reference to FIG. 5 , the authentication validator is connected to a centralized server, which initiates the authentication challenge dynamically once a mobile device initiates a resource access request within a certain proximity to the validator. This challenge can be unique and different each time the validator is approached/initiated. As a result, it is highly unlikely to commit identity fraud. [0054] FIG. 6 shows an embodiment of the invention in which the server communicates the challenge response directly to the mobile device. The validator acts as the middleman only for the challenge response. In the alternative, the challenge response may be sent directly to the server from the mobile device. [0055] As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. [0056] Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. [0057] A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. [0058] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing. [0059] Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). [0060] Aspects of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processsor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. [0061] These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article or manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. [0062] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. [0063] Referring now to FIG. 7 , according to an exemplary embodiment of the present invention, a computer system 701 can comprise, inter alia, a CPU 702 , a memory 703 and an input/output (I/O) interface 704 . The computer system 701 is generally coupled through the I/O interface 704 to a display 705 and various input devices 706 such as a mouse and keyboard. The support circuits can include circuits such as cache, power supplies, clock circuits, and a communications bus. The memory 703 can include RAM, ROM, disk drive, tape drive, etc., or a combination thereof. Exemplary embodiments of present invention may be implemented as a routine 707 stored in memory 703 (e.g., a non-transitory computer-readable storage medium) and executed by the CPU 702 to process the signal from the signal source 708 . As such, the computer system 701 is a general-purpose computer system that becomes a specific purpose computer system when executing the routine 707 of the present invention. [0064] The computer platform 701 also includes an operating system and micro-instruction code. The various processes and functions described herein may either be part of the micro-instruction code or part of the application program (or a combination thereof) which is executed via the operating system. In addition, various other peripheral devices may be connected to the computer platform such as an additional data storage device and a printing device. [0065] The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical functions(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. [0066] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. [0067] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

A method including: receiving, at a first device, a challenge provided from a second device, wherein the challenge includes an encoding algorithm and a request for credentials from the first device; and outputting, from the first device to the second device, a response to the challenge, wherein the response includes at least one image, the at least one image including an article of evidence arranged according to the encoding algorithm.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 10/949,941, filed Sep. 24, 2004 entitled INTEGRATED COUPLER, which application is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of couplers having the function of sampling part of the power present on a main line towards a secondary line for control and feedback. Couplers are generally used in closed-loop gain-control systems to provide a real measurement of the power. 2. Discussion of the Related Art FIG. 1 very schematically shows an example of a conventional circuit using a coupler. This example relates to the control of a power amplifier 1 (PA) for amplifying a useful signal UTI for a transmit antenna 2 . In this type of application, the transmit power is controlled with a power reference PL. A coupler 3 is interposed between the output of amplifier 1 and antenna 2 to extract data proportional to the power actually transmitted. This data is exploited by a detector 4 (DET) providing a measured value MES to a comparator 5 with required power PL. Comparator 5 provides a control signal REG to amplifier 1 . Two large coupler categories are essentially known. A first category relates to so-called distributed couplers, which are formed from coupled transmission lines. A second category relates to couplers with local components, based on capacitors and inductances. Distributed couplers are directional, that is, they detect the direction of the measured power and are sensitive to dimensional variations of the lines. Such couplers are bulky due to the size of the lines to be formed, especially for radio frequency applications (from several hundreds of MHz to a few GHz). Couplers with local components are non-directional. They have the advantage of having a large passband and of being more compact. As illustrated in FIG. 1 , a coupler is defined by four ports or terminals IN, DIR, CPLD, and ISO. Terminals IN and DIR are on the main line while terminals CPLD and ISO define the coupled secondary line. In FIG. 1 , terminal IN is on the side of power amplifier 1 while terminal DIR is on the side of antenna 2 . Terminal CPLD is the terminal on which is sampled the information proportional to the power in the main line. In a non-directional coupler, to which the present invention applies, terminals IN and DIR are one and the same and terminal ISO generally does not exist. The main parameters of a non-directional coupler are: the coupling factor (generally on the order of from 10 to 30 dB) which corresponds to the path loss between ports IN and CPLD (the other port being loaded with a standardized impedance, generally 50 ohms); and the insertion loss in the desired passband which corresponds to the path loss between ports IN and DIR (the other port being loaded with a standardized impedance, generally 50 ohms) and which is desired to be as small as possible (smaller than 1 dB and preferably on the order of 0.5 dB) to minimize the attenuation of the wanted signal due to the presence of the coupler. FIG. 2 shows the electric diagram of a conventional non-directional coupler with local components. Such a coupler is essentially formed of the association of two cells 31 and 32 respectively forming high-pass and low-pass filters. Cell 31 comprises a capacitor C 31 having a first electrode connected to transmit line 12 (confounded terminals IN and DIR) and having a second electrode connected, by an inductance L 31 , to ground. The second electrode of capacitor C 31 also constitutes an input terminal of cell 32 formed of an inductance L 32 connecting this second electrode to terminal CPLD, terminal CPLD being further grounded by a capacitor C 32 . A disadvantage of passive couplers with local components such as that illustrated in FIG. 2 is linked to the dispersions (on the order of 20%) of the inductive and capacitive components upon manufacturing thereof. Such dispersions are reflected on the coupler parameters, which are given for an operating frequency band. Theoretically, it is also possible to form high-pass and low-pass filters based on resistive and capacitive elements to form a coupler. However, the required number of stages (filter order) results, in practice, in a large size filter. Further, the dispersion problem is also present for resistors. Above all, such structures are, in practice, not integrable in high-frequency applications (over one hundred MHz) more specifically aimed at by the present invention, due to the small required values, especially for capacitors (less than one picofarad). SUMMARY OF THE INVENTION The present invention aims at providing a novel integrable coupler architecture. The present invention more specifically aims at providing a non-directional coupler, the parameters of which are free of the dispersion problems of conventional couplers with local components. The present invention also aims at enabling easy and accurate setting of the values of the coupler components. To achieve these and other objects, the present invention provides a non-directional coupler comprising a semiconductor junction in series with a capacitor, the semiconductor junction being formed so that the threshold frequency short of which it behaves as a rectifier is smaller than the coupler's operating frequency. According to an embodiment of the present invention, said semiconductor junction is formed in an epitaxial layer, the thickness of which conditions the threshold frequency from which the junction no longer has a rectifying function. According to an embodiment of the present invention, said capacitor has a value greater than 10 picofarads. According to an embodiment of the present invention, the semiconductor junction is sized to exhibit, at the coupler's operating frequency, a series capacitance on the order of a few hundreds of femtofarads and a series resistance on the order of a few tens of ohms. The foregoing objects, features, and advantages of the present invention will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 , previously described, are intended to show the state of the art and the problem to solve; FIG. 3 shows the diagram of an embodiment of a coupler according to the present invention; FIG. 4 shows a coupler according to the present invention connected to a detector of a control loop of the type illustrated in FIG. 1 ; FIG. 5 shows in a very simplified cross-section view, an example of the forming of a coupler in a silicon wafer according to the present invention. DETAILED DESCRIPTION The same elements have been designated with the same reference numerals in the different drawings. For clarity, only those components which are necessary to the understanding of the present invention have been shown in the drawings and will be described hereafter. In particular, the exploitation that is made of the measurements performed by a coupler according to the present invention has not been described in detail, the present invention applying whatever the type of measurements performed and whatever the transmit line on which the coupler is connected. A feature of the present invention is to form an integrated coupler in the form of a semiconductor junction (PN) in series with a capacitor. FIG. 3 shows an embodiment of a coupler 3 according to the present invention. A PN junction 35 is connected by a first terminal (indifferently P or N) to transmit line 12 (confounded terminals IN and DIR) while its other terminal is connected to a first electrode of a capacitor 36 having its other electrode defining terminal CPLD of the coupler. According to the present invention, PN junction 35 is used, not as a rectifying element but, at the frequencies desired for the coupler operation, to form a capacitor 351 in series with a resistor 352 , both of very small value. “Very small value” means a capacitance 351 of less than one picofarad and a resistance 352 of less than 100 ohms. The PN junction is thus formed to avoid rectifying the signal at relatively high operating frequencies (greater than some hundred MHz) chosen for the coupler. According to a preferred example, it is formed with an intrinsic area (PIN diode), for example, in an epitaxial layer. Capacitor 36 has the function of blocking the D.C. component. Its value is sufficient to be neglected in the series association with capacitor 351 . Preferably, a value greater than 10 picofarads fulfils these requirements. The function of capacitor 36 will be better understood in relation with the description of FIG. 4 integrating the coupler in its application. FIG. 4 shows a coupler 3 according to the present invention shown in the form of a diode 35 in series with a capacitor 36 , and having its terminal CPLD connected to a detection circuit 4 providing a measurement signal MES for a comparator. Circuit 4 is a conventional circuit, for example, of the type illustrated in FIG. 1 . It comprises a rectifying element 41 (for example, a diode) having its anode connected to terminal CPLD and having its cathode connected, via a capacitor 44 , to ground. The cathode of element 41 is further connected, by a resistor 42 , to terminal MES which is grounded by a capacitor 43 . Capacitors 43 and 44 form with resistor 42 a low-pass filter reducing the ripple of the D.C. signal sampled on terminal MES. Detector 4 further comprises a temperature-compensated bias circuit setting a level Vdc on the anode of diode 41 . This circuit is formed of two resistors 45 and 46 in series between a terminal 47 of application of voltage Vdc and the anode of diode 41 . The midpoint of this series connection is grounded by a diode 48 in series with a resistor 49 . Such an assembly enables obtaining an exploitable level even for low powers of signals carried on main line 12 (smaller than 0 dBm). Without this biasing, diode 41 would be blocked for such levels. However, the presence of this bias voltage requires using capacitor 36 to avoid a continuous biasing of PN junction 35 of coupler 3 , which would null out the desired operation. FIG. 5 illustrates an example of integration in a silicon substrate 7 of a PN junction 35 of a coupler according to the present invention. To obtain the desired absence of a rectifying effect, an epitaxial region 71 is provided between a P+ doped region 72 and N+ doped substrate 7 . This is an example, and the doping types may be inverted. A first (anode) contact 73 is taken on region 72 and a second (cathode) contact 74 is taken on the N+ region that is, on substrate 7 . Other junction configurations may be envisaged provided to respect the absence of a rectifying effect at the desired operating frequencies. For example, the PN junction may be formed from a diode-assembled NPN-type bipolar transistor (connected base and collector). The threshold frequency fs from which the PN junction no longer rectifies the signal is a function of the carrier transit time (designated as tt). This frequency is proportional to the inverse of the transit time. If the main line signal has a frequency greater than threshold frequency fs, the voltage switches from a negative value to a positive value and conversely, with a periodicity smaller than the transit time. The forward incursion is too steep to cause a current and the carrier is carried off by the negative halfwave before recombining, and thus before generating a rectified current. Under such circumstances, the PN junction is considered as a capacitor in series with a resistor. As a first approximation, it can be considered that the transit time essentially is a function of the epitaxial layer thickness and of the carrier diffusion coefficient. More specifically, time tt is proportional to W 2 /D, where W represents the thickness of the epitaxial layer and D represents the carrier diffusion coefficient. For a diffusion coefficient of carriers D on the order of 13 cm 2 /s, which is a usual value in present technologies, frequency fs approximately is 1300/W 2 (fs in MHz and W in μm). Generally, in light dopings used to form the diodes, diffusion coefficient D of the carriers can be considered as being constant. Accordingly, the smaller the thickness of the epitaxial layer, the higher the frequency from which the PN junction does not have a rectifying behavior. It should be noted that the doping level of the regions has but little influence on the threshold frequency of the PN junction. A specific example of application of the present invention relates to couplers used in the field of mobile telephony (GSM and DCS). The value of capacitor 351 is on the order of a few hundreds of femtofarads. This value resulting from the diode forming can be adjusted by setting, according to the desired response and taking into account possible stray capacitances, especially the epitaxy doping, the active surface, and the epitaxy thickness in case of a full depletion. Such a value is compatible with frequencies on the order of one GHz. Similarly, resistive component 352 is on the order of a few tens of ohms, which is compatible with the forming of a PN junction and, again, adjustable according to the desired characteristics, by setting the interval between the P+ and N+ regions. It should be noted that, in case of an integration with the detection circuit, the anode of the diode thus formed directly forms the terminal on which line 12 is connected, that is, the antenna and the output of the power amplifier. An advantage of a PN junction to form the coupler is that, in the form of an active coupler, its parameters are controllable even for small capacitance and resistance values, with a much smaller dispersion (linked to the semiconductor technology). The “active” coupler thus becomes integrable. It can then be integrated on a same chip as that of the detection circuit ( 4 , FIG. 4 ). The values to be given to resistance 352 and capacitance 351 by the configuration of junction 35 are determined by usual modeling and simulation tools according to the desired and/or acceptable coupling factor and insertion loss at the selected operating frequencies. Of course, the present invention is likely to have various alterations, modifications, and improvements which will readily occur to those skilled in the art. In particular, the practical forming of a diode fulfilling the constraints given by the present invention to form a coupler is within the abilities of those skilled in the art based on the functional and sizing indications given hereabove. Further, the present invention applies for a lateral diode as well as for a diode made in a vertical technology and whatever the type of formed diode (PN diode, PIN diode, etc.), provided that it is sufficiently slow with respect to the desired operating frequencies. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present invention. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto.

A non-directional coupler including a semiconductor junction in series with a capacitor, the semiconductor junction being formed so that the threshold frequency short of which it behaves as a rectifier is smaller than the coupler's operating frequency.

CROSS REFERENCE TO RELATED APPLICATION This application claims the priority of German Patent Application No. 103 31 759 dated 14 Jul. 2003, the disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION The invention relates to an apparatus on a draw frame for textile fibre slivers with a drawing system of successively arranged pairs of rollers comprising a bottom and a top roller in which a load can be applied to the top rollers. During operation of a draw frame of the above-mentioned kind, the top rollers are pressed against the bottom rollers by weighted pressing elements in pressing arms. When operation is suspended, the bearings of the top rollers are relieved of the loading by the pressing arms and upon interruption to continuous operation the top output roller or the top output rollers are relieved of loading such that no or only slight pressure is exerted on the fibre slivers. During operation, the pressing arms are closed and the pressing devices press the top rollers onto the associated lower rollers of the drawing system. When operation of the drawing frame is suspended, particularly for a longer time period, the pressure cylinders and hence at the same time the top rollers are relieved of load, so that the rollers (roundness) and their resilient coating are protected against deformation. When the pressing arms are pivoted open while the top rollers remain stationary on the lower rollers, the top rollers exert a pressure on the bottom rollers by virtue of gravity. Since the slivers are positioned between the top and bottom rollers, the top rollers, in their idle state, exert a pressure on the slivers. During operation, particularly at high sliver speeds of 1,000 m/min and above, the rollers heat up substantially. The fibres frequently contain substances that become sticky when heated, for example, honeydew in the case of cotton and lubricating agents in the case of synthetic fibres. When the draw frame is at a standstill for a relatively long period—especially for longer than the time required to exchange full for empty cans at the output end of the draw frame—for example, on sliver rupture, when exchanging empty for full cans at the input end of the draw frame, during operational disturbances and the like, the top output roller(s) in particular, at the roller nip with the bottom output rollers, press against the substances clinging to the fibres and the substances become sticky owing to the heat. The disadvantage of this is that the slivers stick firmly especially to the top roller or top rollers and, when operation resumes, are entrained by the rotating roller and wind undesirably around the roller. This causes considerable disturbance to operation, since the drawing system is immediately stopped and the wrapped-round sliver has to be manually removed. In particular, the incident can often not be immediately resolved, which leads to delays and thus to production losses. In a known apparatus (DE 198 39 885 A1), at least one separately controllable pneumatic valve for the pneumatic cylinder is associated with the top output roller and/or the top output rollers and at least one adjustable carrier lever or similar for the top output roller is associated with the pneumatic cylinder. By pulling in the ram, the carrier lever is drawn up and with it, the associated top roller bearing. In order to realise two loading functions of the pressure cylinder, that is, a push function and a pull function, a complicated valve device with corresponding valve control (separately controllable pneumatic valve) is required. It is an aim of the invention further to improve an apparatus of the kind described in the introduction, and to provide a draw frame which avoids or mitigates the said disadvantages and in which in particular the undesirable formation of windings is avoided or reduced. SUMMARY OF THE INVENTION The invention provides a draw frame for textile fibre slivers having a drawing system comprising: a first roller assembly and a second roller assembly, said first and second roller assemblies being arranged one after the other and each comprising a bottom roller and a top roller having first and second top roller bearings; a loading arrangement for applying a load to said top rollers so as to press said top rollers against said respective bottom rollers, which load can be substantially relieved by the loading arrangement; and a lifting arrangement for lifting a said top roller from a said bottom roller when said load is substantially relieved. Advantageously, the lifting arrangement comprises: a first resiliently loaded element associated with a first top roller bearing of a said top roller; a second resiliently loaded element associated with a second top roller bearing of that roller; said first and second resiliently loaded elements being arranged for lifting said first and second top roller bearings when the load applied by the loading arrangement is substantially relieved. Advantageously, the lifting arrangement comprises first and second resilient loading elements for loading said first and second resiliently loaded elements. When operation is interrupted, the bearing pressure of the top rollers on the fibre slivers is absent or substantially absent and, in particular, the top roller engages only slightly or not at all with the fibre material, so that heating of substances in the fibre material, and thus the adhesive effect, are avoided. The fibre slivers are thus effectively prevented from undesirably adhering to the rollers, so that entrainment upon re-start and hence the formation of a winding around the rollers does not occur. Because a resilient element, preferably a mechanical compression spring, is provided to lift the top roller bearing, a substantial structural simplification is achieved. Unlike the known apparatus, a separately controllable valve control for lifting the top roller is not present. A particular advantage is the fact that each time the top roller bearings are relieved of the pressure exerted by, for example, a pneumatic ram (that is, the pressure is reduced or removed), the resilient element automatically relaxes, and as a result, the top roller bearings are lifted from the bottom roller bearings including the top rollers from the bottom rollers. Advantageously, at least one said resiliently loaded element is a driver element. At least one said loaded element is advantageously loaded by a spring, for example, a compression spring. Advantageously, as driver element an angle lever, angled plate or the like is provided. Advantageously, one angle arm of the driver element engages beneath the top roller bearing or the bearing stub. Advantageously, the free end of a resilient element, for example, compression spring, loads the driver element. Advantageously, a resilient element, for example, compression spring, is supported on a fixed bearing. Advantageously, the line of action of the ram and the line of action of at least one resilient element, for example, compression spring, run substantially axially parallel to one another. Advantageously, at least one resilient element, for example, compression spring, is tensioned in continuous operation. Advantageously, each time the pressing elements are relieved of loading, a said resilient element, for example, compression spring, relaxes. Advantageously, the relaxation of the resilient element, for example, compression spring, is effected automatically. Advantageously, lifting of the top roller bearings or the bearing stubs is effected upon extended interruption of continuous operation. Advantageously, lifting of the top roller bearings or the bearing stubs is effected within a short time. Advantageously, upon continuation of continuous operation, the loading of the top rollers and the tensioning of the resilient elements, for example, compression springs, are effected automatically. Advantageously, upon continuation of continuous operation, the loading of the top rollers and the tensioning of the resilient elements, for example, compression springs, are effected simultaneously. Advantageously, a 4-over-3 drawing system is present, the top roller nearest the output—viewed in the direction of travel of the textile fibre material—is relieved of loading. Advantageously, the top roller is a deflecting roller. Advantageously, at least one top output roller is lifted away from the bottom output roller. Advantageously, a spacing is present between the top output roller and/or the top output rollers and the fibre slivers. Advantageously, upon machine standstill at least one top roller is capable of being bought automatically out of contact with the fibres. Advantageously, the last top roller in the material running direction is capable of being brought automatically out of contact with the fibres. Advantageously, upon re-start of the machine the previously lifted roller is capable of being returned automatically into engagement under pressure loading. Advantageously, a mechanical element is provided as resilient element. Advantageously, adjustment devices, for example, threaded pins or the like, are provided for adjustment of the position of the driver element. The invention also provides a draw frame for textile fibre slivers, having a drawing system comprising a roller to which in use a load can be applied, the load being relievable when the draw frame is not in operation, the draw frame further comprising a lifting arrangement for lifting said roller away from a second roller with which it is in co-operation during operation of the draw frame, when the load is relieved. Moreover, the invention provides apparatus on a draw frame for textile fibre slivers with loading of the top rollers of the drawing system of successively arranged pairs of rollers comprising a bottom and a top roller, in which, during operation, the top rollers are pressed against the bottom rollers by weighted pressing elements in pressing arms, wherein the bearings of the top rollers, at standstill, are relieved of the loading by the pressing arms and the top output roller or the top output rollers is/are capable of being relieved of pressure on interruption to continuous operation so that no or only slight pressure is exerted on the fibre slivers, wherein respective resiliently loaded elements are associated with the bearings of at least one top roller and lift the top roller bearings when the pressing elements are relieved of loading. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of the drawing system of a draw frame with an arrangement according to the invention; FIG. 2 shows part of FIG. 1 in the section corresponding to K-K ( FIG. 1 ) with a pneumatic top roller loading device; FIG. 3 is a front view of a pressing arm with integral housing and two rams, FIG. 3 a is a perspective view of pressing arm shown in FIG. 3 ; FIG. 4 a is a front view, partly in section, of a top roller bearing loaded by a ram on one side and a bearing stub loaded by a tensioned spring, top and bottom roller being located one on top of the other with no gap between them; FIG. 4 b shows a the top roller bearing of FIG. 4 a relieved of loading by the ram and the bearing stub lofted with the relaxed spring, top roller and bottom roller having a gap between them; FIG. 4 c shows in detail the spring-loaded angle lever shown in FIGS. 4 a and 4 b; FIG. 5 a is a front view, partly in section, of a top roller bearing of the top roller of FIGS. 4 a to 4 c , loaded by a ram and a bearing stub loaded with a tensioned spring, top and bottom roller (as in FIG. 4 a ) being located one on top of the other; FIG. 5 b shows the top roller bearing relieved of loading by the ram and the bearing stub lifted with the relaxed spring, top roller and bottom roller (as in FIG. 4 b ) having a gap between them; FIG. 5 c shows in detail the spring-loaded angle lever shown in FIGS. 5 a and 5 b; FIG. 6 a shows a drawing system of a draw frame according to the invention in operation with the top rollers loaded, and FIG. 6 b shows the drawing system of FIG. 6 a when operation is suspended, with the top rollers relieved of load and with the top output roller (deflecting roller) lifted. DESCRIPTION OF PREFERRED EMBODIMENTS With reference to FIG. 1 , a drawing system S of a draw frame, for example, an HSR (Trade Mark) draw frame made by Trütrutzschler GmbH & Co. KG of Mömonchengladbach, Germany, is provided. The drawing system S is designed as a 4-over-3 drawing system, that is, it comprises three bottom rollers I, II, III (I being the bottom output roller, II the middle bottom roller, III the bottom intake roller) and four top rollers 1 , 2 , 3 , 4 . Drafting of the composite sliver 5 from a plurality of fibre slivers takes place in the drawing system S. The draft is made up from the preliminary draft and the main draft, and the roller pairs 4 /III and 3 /II form the preliminary drafting zone and the roller pairs 3 /II and 1 , 2 /I form the main drafting zone. The bottom output roller I is driven by the main motor (not shown) and hence determines the rate of delivery. The bottom intake and middle bottom rollers III and II respectively are driven by a variable speed motor (not shown). The top rollers 1 to 4 are pressed against the bottom rollers I, II, III by pressing elements 9 1 to 9 4 (weighting device) in pressing arms 11 a to 11 d pivotable about pivot bearings (for example, as shown in FIGS. 3 and 4 a ), and are hence driven by way of frictional engagement. The direction of rotation of the rollers I, II, III; 1 , 2 , 3 , 4 is indicated by curved arrows. The composite fibre sliver 5 , which consists of a plurality of fibre slivers, runs in direction A. The bottom rollers I, II, III are mounted in bearers 14 (see FIG. 3 ) which are arranged on the machine frame 15 . Referring to FIG. 2 , an upper supporting element 12 and a lower holding element 13 a are associated with the pneumatic cylinder 9 . The pneumatic cylinder 9 forms a cylinder unit having a cylinder cavity 17 comprising two parts 17 a and 17 b , in which a piston 18 is guided by means of a ram 19 in a sliding bushing 20 . The roller journal 4 a of the pressure roller 4 passes right through an opening in a holding plate 27 a and engages in a bearing 22 a . The bearing 22 a receiving the pressure roller 4 extends into a space between the ram 19 and the roller journal IIIa of the bottom roller III. The bearing 22 a is mounted on the holding element 13 a . A diaphragm 16 divides the cylinder cavity 17 into pressure regions. In order to generate pressure in the upper part 17 a of the cylinder cavity 17 , compressed air p 1 can be admitted to this space by means of a compressed air connection 23 . Air is evacuated from the lower part 17 b of the cylinder cavity 17 through a vent bore 24 . Analogously, air can be evacuated from the upper part of the cylinder cavity 17 and compressed air can be admitted to the lower part of the cylinder cavity 17 . In operation, after a fibre sliver 5 has been guided over the bottom rollers I, II, III, the pressing arms 11 are pivoted into the working position shown in FIG. 4 a and fixed in this position by a fixing device (not shown), so that the pressure rollers I, II, III are able to exert pressure. Application of pressure occurs on the one hand as a consequence of each of the rams 19 being located on the corresponding bearing 22 , and on the other hand in that an overpressure is generated in the void above the diaphragm 16 . The ram 19 therefore presses with its other end on the bearing 22 , in order to generate the said clamping between the top roller 4 and the bottom roller (drive roller) III. The ram 19 is displaceable in the direction of the arrows D, E. Referring to FIGS. 3 , 3 a , the top roller 4 has associated with it a portal-form pressing arm 11 a . (A corresponding pressing arm 11 b , 11 c , 11 d (not shown) is associated with each of the top rollers 2 to 4 ). In the embodiment shown in FIG. 3 , the pressing arm 11 a is in the form of a housing 11 of glass fibre-reinforced plastics and is manufactured by injection moulding. The housing 11 has an inner housing 30 which is an integral component of uniform construction comprising the supporting element 12 , the two bodies of the pressing elements 9 a 1 and 9 a 2 (pressure cylinders), two intermediate elements 31 a and 31 b , and two holding elements 13 a and 13 b . The supporting element 12 is in the form of a channel 12 a of approximately U-shaped cross-section open on one side, pneumatic lines 34 and electrical leads 35 being arranged in the interior of the channel. The open side of the channel 12 a is closable by a removable cover 36 , which consists of glass fibre-reinforced plastics material, has an approximately U-shaped cross-section and is resilient, such that it is fixed by an interference fit on the channel 33 . The housing 30 is preferably of one-piece construction. The integral housing 30 , which combines all the essential function elements for mounting and weighting the respective top rollers 1 to 4 , can thus be manufactured economically. At the same time, in a simple manner the entire pressing arm 11 a to 11 d is rotatable about the centre of rotation 10 and can be locked and unlocked by a locking device 26 (for example, as shown in FIG. 5 a ). The rams 19 a and 19 b are relieved of pressure and hence lifted a distance b 1 , b 2 from the bearings 22 a to 22 b of the top roller 4 (see FIGS. 4 b , 5 b ). In the embodiment of FIG. 4 a , on one side of the top roller 4 the top roller bearing 22 a is pneumatically loaded by the ram 19 a . The top roller 4 and the bottom roller III are located one on top of the other with no gap between them. An angle lever 36 a having two angle arms 36 a I and 36 a II projecting at right angles, one at each end, is mounted on the holding element 13 a as driver element. As FIG. 4 c illustrates, the angle arm 36 a I engages beneath the bearing stub 25 a of the bearing 22 a . The other angle arm 36 a II is resiliently biased by a compression spring 37 , which is supported on the holding element 13 a . The line of action 38 of the compression spring 37 and the line of action 39 of the ram 19 a are parallel with one another. The angle lever 36 a is mounted so that it is displaceable relative to the holding element 13 a in the direction of the arrows F, G, whereby the position of the angle lever 36 a is adjustable (when the pressing arm 11 a is without pressure). According to FIG. 5 a , on the other side of the top roller 4 , the top roller bearing 22 b is pneumatically loaded by the ram 19 b . An angled plate 36 b (see FIG. 5 b ) is arranged as driver element on the holding element 13 b ; at one end of the angled plate an angle arm 36 b I projects at right angles. As FIG. 5 c shows, the angle arm 36 b I engages beneath the bearing stub 25 b of the bearing 22 b . The angled plate 36 b is resiliently biased by a compression spring 40 , which is supported on the holding element 13 b . The line of action 41 of the compression spring 40 and the line of action 42 of the ram 19 b are axially parallel with one another. The angled plate 36 b is mounted so that it is displaceable relative to the holding element 13 b in the direction of the arrows F, G. The reference numeral 43 denotes a latching and unlatching element for the top roller 4 , pivotally mounted around a pivot bearing 44 . A threaded pin 45 acts on the angled plate 36 b , whereby the position of the angled plate 36 b (when the pressing arm 11 a is without pressure) is adjustable. In operation, corresponding to FIGS. 4 a , 5 a , the rams 19 a and 19 b load the top roller bearings 22 a respectively 22 b in direction D. In this way, the bearing stubs 25 a and 25 b mounted on the top roller bearings 22 a , 22 b respectively are also pressed downwards in direction M. Via the angle arm 36 a I and via the angle arm 36 b I , the angle lever 36 a and the angled plate 36 b , and the bearing stubs 25 a and 25 b , are pulled downwards in direction F—against the force of the respective compression springs 37 and 40 . At the same time and automatically, the compression springs 37 and 40 are consequently tensioned in direction N. When operation is suspended, corresponding to FIGS. 4 b , 5 b , and the rams 19 a and 19 b are now relieved of loading in direction E, a gap b 1 respectively b 2 is present between the end of the rams 19 a and 19 b and the top roller bearings 22 a , 22 b respectively. Because the top roller bearings 22 a and 22 b have been relieved of loading, and by virtue of the gaps b 1 and b 2 , the bearing stubs 25 a and 25 b are likewise relieved of loading in direction L. Owing to the relaxation of the compression springs 37 and 40 , the bearing stubs 25 a and 25 b are pulled upwards or lifted in direction G by way of the angle lever 36 a and the angled plate 36 b , by means of the angle arm 36 a I and the angle arm 36 b I respectively. At the same time and automatically, the compression springs 37 and 40 consequently relax in direction O. Referring to FIG. 6 a , in operation the top output rollers 1 and 2 lie on the bottom output roller I with applied loading, the fibre material 5 running through between the top output rollers 1 and 2 and the bottom output roller I. Upon extended stoppage time—which is detected in the electronics control and regulating device, not shown, for the drive motors—the top output roller 1 is relieved of loading and immediately thereafter, as shown in FIG. 6 b , lifted by the distance c away from the fibre material 5 and the bottom output roller I. This prevents the fibre material 5 from adhering via foreign bodies and so on, as a result of pressure, to the top output roller 1 . Because the top output roller 2 is now relieved of loading and hence remains in place by gravity, the fibre material 5 remains firmly clamped and held between the top output roller 2 and the bottom output roller I and, upon re-start, can be guided without problem by the top output roller 1 and the bottom output roller I. Except where the opposite is apparent, the same reference numerals are used to indicate corresponding parts in each of the drawings The invention has been described by the example of pneumatic pressing elements (loading elements). Alternatively, mechanical, hydraulic or electrical pressing elements for loading the top rollers 1 to 4 can be used. In practice, many loops appear around the deflecting roller 1 , usually caused by lubricating agents and adhesive particles present on the fibres. After an operational disturbance in the machine (sliver rupture, coiler can change or the like), the machine attendants are often not able to resolve such incidents immediately. The draw frame relieves the drawing system of loading after an interruption occurs, but the hot deflecting roller 1 lies on the fibres 5 under its own weight. If the deflecting roller 1 lies for an extended period on the sticky fibres 5 , these adhere to the deflecting roller 1 and upon restart, the sticky fibres 5 wrap themselves around the deflecting roller 1 . The measures according to the invention enable the deflecting roller 1 to be lifted by means of a resiliently loaded driver element 36 a , 36 b . By lifting the deflecting roller 1 , the fibres 5 can no longer stick to the roller, and the pressure on the lower roller 1 is reduced, whereby the wrap-round tendency is considerably reduced. The reduction in the wrap-round tendency significantly increases the efficiency of the draw frame when sticky fibres are being processed, because operational disturbances and their elimination are reduced or avoided Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims.

A draw frame for textile fiber slivers has a drawing system of successively arranged assemblies of rollers comprising a bottom and a top roller, in which, during operation, the top rollers are pressed against the bottom rollers by weighted pressing devices. When operation is suspended, the bearings of the top rollers are relieved of the weighting by the pressing devices. On interruption to continuous operation the top output roller or the top output rollers is/are capable of being relieved of loading in such a way that no or only slight pressure is exerted on the fiber slivers. To avoid or reduce undesirable formation of windings in a simple manner, resiliently loaded elements that lift the top roller bearings after the pressing devices have been relieved of loading are associated with the bearings of at least one top roller.